# Advice on Dimmer mod for Gene Cafe



## RA5040

I would like to implement the dimmer mod from CoffeeTime (great article BTW!). I would prefer to use the Varilight IQP1001W dimmer instead of the Varilight HQ9W as it is easier for me to get it (I live in Ireland). They look much the same to me ... but I wonder if the HQ9W was picked for a specific reason, or if any good quality 1000W dimmer would do the job? (I understand from the article that Varilight make good dimmers, so I've stuck to that make).

The article mentions a target cost of £20 for the 230V heater mod (which I would also like to do). I haven't found a heater element for the Gene ... only the £74 Heater Box from BellaBarista. Does anyone know where the element can be purchased or is it necessary to buy the whole heater box?

Thanks

Robert


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## DavecUK

RA5040 said:


> I would like to implement the dimmer mod from CoffeeTime (great article BTW!). I would prefer to use the Varilight IQP1001W dimmer instead of the Varilight HQ9W as it is easier for me to get it (I live in Ireland). They look much the same to me ... but I wonder if the HQ9W was picked for a specific reason, or if any good quality 1000W dimmer would do the job? (I understand from the article that Varilight make good dimmers, so I've stuck to that make).
> 
> The article mentions a target cost of £20 for the 230V heater mod (which I would also like to do). I haven't found a heater element for the Gene ... only the £74 Heater Box from BellaBarista. Does anyone know where the element can be purchased or is it necessary to buy the whole heater box?
> 
> Thanks
> 
> Robert


You have to buy the whole heater box.

I chose the Varilight because when I rang their tech department and told them what I was proposing to do to make it handle the 1300W of the Gene, they said they were doing exactly the same thing to make a 1500W custom version of the dimmer for a big customer. Effectively just increasing the heatsink size. Of course now you can buy SCR controllers from Ebay that will handle 4kW for £6, as I used on the Amazon Dalian -see the separate article on that to find the dimmer.


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## RA5040

DavecUK said:


> You have to buy the whole heater box.
> 
> I chose the Varilight because when I rang their tech department and told them what I was proposing to do to make it handle the 1300W of the Gene, they said they were doing exactly the same thing to make a 1500W custom version of the dimmer for a big customer. Effectively just increasing the heatsink size. Of course now you can buy SCR controllers from Ebay that will handle 4kW for £6, as I used on the Amazon Dalian -see the separate article on that to find the dimmer.


Thanks ... actually I was thinking of using an SCR voltage regulator, but I couldn't find one for 240V (they all seem to be for 220V). Is a 220V SCR OK to use on 240V mains? ... and if so will it give the full voltage to the heater or is there a voltage drop? My mains voltage here seems pretty stable at around 240V.

Pity about the heater element ... £74 + shipping is a bit steep!

Cheers

Robert


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## MediumRoastSteam

Mine says 220V.... it's been working just fine.

Here is my journey when I did my mod.

Gene Cafe CBR-101 Dimmer Mod - MediumRoastSteam take on it

https://r.tapatalk.com/shareLink?share_fid=6813&share_tid=41014&url=https%3A%2F%2Fcoffeeforums%2Eco%2Euk%2Fshowthread%2Ephp%3Ft%3D41014&share_type=t


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## ajohn

This item might interest people into modification / making a bean roaster etc

https://www.ebay.co.uk/itm/12V-30-999-Digital-High-Temperature-Control-Switch-Thermostat-K-Thermocouple/182171883615?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It seems to be a modification of one that usually does up to 99C. My interest stems from using a rotary spit oven for bean roasting as I expect the thermostat in it to be crap - it does do good whole chickens though but from setting for that I know the temp scale is out and that the thermostat has a lot of hysteresis, probably way more than needed to cope with overshoot. Hystereses can be set and the temperature calibrated if needed.

John

-


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## RA5040

ajohn said:


> This item might interest people into modification / making a bean roaster etc
> 
> https://www.ebay.co.uk/itm/12V-30-999-Digital-High-Temperature-Control-Switch-Thermostat-K-Thermocouple/182171883615?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
> 
> It seems to be a modification of one that usually does up to 99C. My interest stems from using a rotary spit oven for bean roasting as I expect the thermostat in it to be crap - it does do good whole chickens though but from setting for that I know the temp scale is out and that the thermostat has a lot of hysteresis, probably way more than needed to cope with overshoot. Hystereses can be set and the temperature calibrated if needed.
> 
> John
> 
> -


Hmmm ... interesting, but I don't see how one would use this practically with a drum roaster though. For your spit roaster you might have a look at the Inkbird BBQ thermometer with bluetooth (available on Amazon). It has a very nice android app that has alarms and graphs.


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## RA5040

Thank you! The idea of using a power monitor in the same box is great!


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## DavecUK

MediumRoastSteam said:


> Mine says 220V.... it's been working just fine.
> 
> Here is my journey when I did my mod.
> 
> Gene Cafe CBR-101 Dimmer Mod - MediumRoastSteam take on it
> 
> https://r.tapatalk.com/shareLink?share_fid=6813&share_tid=41014&url=https%3A%2F%2Fcoffeeforums%2Eco%2Euk%2Fshowthread%2Ephp%3Ft%3D41014&share_type=t


Be great if that was added to the Coffeetime Wiki, you can add it if you want. My original article is 10 years or so old now, so there are much better ways of doing it now.


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## MediumRoastSteam

DavecUK said:


> Be great if that was added to the Coffeetime Wiki, you can add it if you want. My original article is 10 years or so old now, so there are much better ways of doing it now.


I would be a pleasure DavecUK! I'll sort something out at the weekend.


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## RA5040

MediumRoastSteam said:


> Mine says 220V.... it's been working just fine.
> 
> Here is my journey when I did my mod.
> 
> Gene Cafe CBR-101 Dimmer Mod - MediumRoastSteam take on it
> 
> https://r.tapatalk.com/shareLink?share_fid=6813&share_tid=41014&url=https%3A%2F%2Fcoffeeforums%2Eco%2Euk%2Fshowthread%2Ephp%3Ft%3D41014&share_type=t


Great! The idea of having a power meter in the same control box as the voltage regulator is really great!

Do you think it is necessary to have a switch, or would you just run the roast off the VR?

Cheers

Robert


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## MediumRoastSteam

RA5040 said:


> Great! The idea of having a power meter in the same control box as the voltage regulator is really great!
> 
> Do you think it is necessary to have a switch, or would you just run the roast off the VR?
> 
> Cheers
> 
> Robert


I'd put a switch so you can bypass the whole thing all together.


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## RA5040

MediumRoastSteam said:


> I'd put a switch so you can bypass the whole thing all together.


Thanks, I'm looking forward to your article!


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## MediumRoastSteam

RA5040 said:


> Thanks, I'm looking forward to your article!


It's on that thread - the whole wiring diagram, components and everything.


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## MediumRoastSteam

RA5040 said:


> Thanks, I'm looking forward to your article!


It's on that thread - the whole wiring diagram, components and everything.


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## ajohn

RA5040 said:


> I would like to implement the dimmer mod from CoffeeTime (great article BTW!). I would prefer to use the Varilight IQP1001W dimmer instead of the Varilight HQ9W as it is easier for me to get it (I live in Ireland). They look much the same to me ... but I wonder if the HQ9W was picked for a specific reason, or if any good quality 1000W dimmer would do the job? (I understand from the article that Varilight make good dimmers, so I've stuck to that make).
> 
> The article mentions a target cost of £20 for the 230V heater mod (which I would also like to do). I haven't found a heater element for the Gene ... only the £74 Heater Box from BellaBarista. Does anyone know where the element can be purchased or is it necessary to buy the whole heater box?
> 
> Thanks
> 
> Robert


Looking at a Chinese scr which is actually triac regulator I have it uses an ST triac rated at 600v, Max on state voltage at 1.7v @ 28A. So you should expect to see a drop a bit over a volt. Surprised me as I expected to see a Chinese part number. It's one of the ones where the adjustment pot is on leads not soldered to the board. Don't get carried away with 28 amps being mentioned. It's a 15amp device but would need a pretty large heatsink to get near to that. It's this one, 2kw probably is a realistic rating

https://www.amazon.co.uk/gp/product/B075QFQN7S/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Not sure why you want a heater box so no comment.

John

-


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## RA5040

ajohn said:


> Looking at a Chinese scr which is actually triac regulator I have it uses an ST triac rated at 600v, Max on state voltage at 1.7v @ 28A. So you should expect to see a drop a bit over a volt. Surprised me as I expected to see a Chinese part number. It's one of the ones where the adjustment pot is on leads not soldered to the board. Don't get carried away with 28 amps being mentioned. It's a 15amp device but would need a pretty large heatsink to get near to that. It's this one, 2kw probably is a realistic rating
> 
> https://www.amazon.co.uk/gp/product/B075QFQN7S/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
> 
> Not sure why you want a heater box so no comment.
> 
> John
> 
> -


Thanks. I was going to use this one https://www.amazon.co.uk/gp/product/B0154I3ZUY/ref=ox_sc_act_title_3?smid=A38I4T5NBLJJJ3&psc=1, but the one you suggest should be fine too.

The reason for the heater box is explained in this article: http://coffeetimex.wikidot.com/gene-cafe-dimmer-control-mod-stage-2. As far as I understand it's to compensate for low voltages (bad mains, but also for drops due to the dimmer/voltage regulator). I won't do this mod unless I find that I need it as I have good mains voltages here normally.

Robert


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## RA5040

I would appreciate it if someone would check out this circuit for the power mod:









So I'm proposing to:

- disconnect both of the heater connections to the Gene board sockets

- connect the heater live socket on the Gene board either to the voltage regulator, or directly back to the heater via the switch

- connect the heater neutral socket on the Gene board to the voltage regulator and loop it back to the heater

- connect the voltage/current/power meter across the heater

- pass the heater live wire through the current sensing torroid to measure current and power

I'm proposing to use the following parts:

- Voltage Regulator: https://www.amazon.co.uk/gp/product/B0154I3ZUY/ref=ox_sc_act_title_3?smid=A38I4T5NBLJJJ3&psc=1

- Meter: https://www.amazon.co.uk/gp/product/B01F37GFE4/ref=ox_sc_act_title_2?smid=A38I4T5NBLJJJ3&psc=1

- Switch: https://www.amazon.co.uk/gp/product/B00EZI4B9O/ref=ox_sc_act_title_1?smid=A3P5ROKL5A1OLE&psc=1

- Box: https://www.amazon.co.uk/gp/product/B071GRDPZG/ref=ox_sc_act_title_1?smid=A1JQD8FFNWUAB1&psc=1

I'm getting everything from Amazon as it's all free shipping and the prices are pretty good (also great for returns if there's a problem!).

I hope that makes sense and is at least a bit correct









Robert


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## MediumRoastSteam

RA5040 said:


> I would appreciate it if someone would check out this circuit for the power mod:
> 
> View attachment 35259
> 
> 
> So I'm proposing to:
> 
> - disconnect both of the heater connections to the Gene board sockets
> 
> - connect the heater live socket on the Gene board either to the voltage regulator, or directly back to the heater via the switch
> 
> - connect the heater neutral socket on the Gene board to the voltage regulator and loop it back to the heater
> 
> - connect the voltage/current/power meter across the heater
> 
> - pass the heater live wire through the current sensing torroid to measure current and power
> 
> I'm proposing to use the following parts:
> 
> - Voltage Regulator: https://www.amazon.co.uk/gp/product/B0154I3ZUY/ref=ox_sc_act_title_3?smid=A38I4T5NBLJJJ3&psc=1
> 
> - Meter: https://www.amazon.co.uk/gp/product/B01F37GFE4/ref=ox_sc_act_title_2?smid=A38I4T5NBLJJJ3&psc=1
> 
> - Switch: https://www.amazon.co.uk/gp/product/B00EZI4B9O/ref=ox_sc_act_title_1?smid=A3P5ROKL5A1OLE&psc=1
> 
> - Box: https://www.amazon.co.uk/gp/product/B071GRDPZG/ref=ox_sc_act_title_1?smid=A1JQD8FFNWUAB1&psc=1
> 
> I'm getting everything from Amazon as it's all free shipping and the prices are pretty good (also great for returns if there's a problem!).
> 
> I hope that makes sense and is at least a bit correct
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Robert


I like the switch 

Did you see the wiring diagram I made on the thread aforementioned?

I'm not an electrician so can't comment much on your diagram. 

Also do notice that because you (and I) are picking the life and neutral from the heater control board, the meter only comes on when the heater is on. Thus, if the element flicks (you don't that to happen, that's what the mod is for) the display will flick too.

Also the box I chose for mine was thick, and there was no way I could fit / attach the dimmer or the switch well. I had to shave off a lot of the ABS, and, for the dimmer, I resorted to a cut out do Celebrations box which is thinner.


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## ajohn

RA5040 said:


> Thanks. I was going to use this one https://www.amazon.co.uk/gp/product/B0154I3ZUY/ref=ox_sc_act_title_3?smid=A38I4T5NBLJJJ3&psc=1, but the one you suggest should be fine too.
> 
> The reason for the heater box is explained in this article: http://coffeetimex.wikidot.com/gene-cafe-dimmer-control-mod-stage-2. As far as I understand it's to compensate for low voltages (bad mains, but also for drops due to the dimmer/voltage regulator). I won't do this mod unless I find that I need it as I have good mains voltages here normally.
> 
> Robert


There are 2 "drops" due the regulators of this type. The volts across it which I mentioned the other is a bit different. They may not reach 100% on but the off time will be when the mains voltage is low. Around 30 to 40v with the circuit they use. Sounds terrible but it's not that bad as the sinusoidal 50hz mains takes under a msec to get there and the peak voltage is just short of 340v.







Sorry I'm not going to work out what that means in loss of power transfer. I'd get a headache trying to remember how accurately. An approximation comes up with under 2%.*

What I would do if the loss matters is switch it in and out. Maybe a 1 pole 2 way selecting either the mains side it's controlling from or it's output to the heater.

John

-

*Maybe some one will do it correctly. I assumed linear to 45 degrees which it more or less is and work back using volt seconds to dc.


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## RA5040

MediumRoastSteam said:


> I like the switch
> 
> Did you see the wiring diagram I made on the thread aforementioned?
> 
> I'm not an electrician so can't comment much on your diagram.
> 
> Also do notice that because you (and I) are picking the life and neutral from the heater control board, the meter only comes on when the heater is on. Thus, if the element flicks (you don't that to happen, that's what the mod is for) the display will flick too.
> 
> Also the box I chose for mine was thick, and there was no way I could fit / attach the dimmer or the switch well. I had to shave off a lot of the ABS, and, for the dimmer, I resorted to a cut out do Celebrations box which is thinner.


Hi ... no, I didn't see the wiring diagram. Could you give me a link to it? (I did look through the post but I didn't see a diagram).

Yes, you're right about the meter going on and off when the heater is turned on and off. This is a tricky problem because we don't want to have a simpler circuit that takes the heater power directly off mains (not off the Gene heater live feed) as this would bypass all of the Gene safety features including turning off at roast end. What we can do of course is to set the Gene temperature to max always and always run the heater off the voltage regulator ... which would be a sensible way to run the roast. In that case, the DPDT switch can be removed as it serves no purpose. Instead, what I would suggest is to use a connector like this one:

https://www.amazon.co.uk/gp/product/B0001P0SCE/ref=ox_sc_act_title_3?smid=A3P5ROKL5A1OLE&psc=1

so that the box can be disconnected quickly. A loop-back plug can then be plugged in to re-connect the live feed connection to the heater to restore normal Gene control.

So something like this:









Robert


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## MediumRoastSteam

RA5040 said:


> Hi ... no, I didn't see the wiring diagram. Could you give me a link to it? (I did look through the post but I didn't see a diagram).
> 
> Yes, you're right about the meter going on and off when the heater is turned on and off. This is a tricky problem because we don't want to have a simpler circuit that takes the heater power directly off mains (not off the Gene heater live feed) as this would bypass all of the Gene safety features including turning off at roast end. What we can do of course is to set the Gene temperature to max always and always run the heater off the voltage regulator ... which would be a sensible way to run the roast. In that case, the DPDT switch can be removed as it serves no purpose. Instead, what I would suggest is to use a connector like this one:
> 
> https://www.amazon.co.uk/gp/product/B0001P0SCE/ref=ox_sc_act_title_3?smid=A3P5ROKL5A1OLE&psc=1
> 
> so that the box can be disconnected quickly. A loop-back plug can then be plugged in to re-connect the live feed connection to the heater to restore normal Gene control.
> 
> So something like this:
> 
> View attachment 35261
> 
> 
> Robert


Diagram on the opening post #1. It's the 5th picture in the post, or the 2nd from the bottom.

I thought about the plug too. But part of me thinks that is safer with the wire always connected, and, in reality, I'm unlikely to use the Gene without it.


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## RA5040

MediumRoastSteam said:


> Diagram on the opening post #1. It's the 5th picture in the post, or the 2nd from the bottom.
> 
> I thought about the plug too. But part of me thinks that is safer with the wire always connected, and, in reality, I'm unlikely to use the Gene without it.


Ha! ... I was looking at the 'My take on it post'!.

If understand your diagram correctly (and I don't think I do), the circuit looks like this:









So the meter is in series (whereas in my proposed circuit it's in parallel) and it provides power to the heater either directly or via the voltage regulator, depending on the position of the switch.

I take it that there's a connection from neutral to the voltage regulator?

Have you tried running your roast with the regulator on for the full duration, including pre-heat if applicable? Any issues like power drop compared to feeding the heater direct?

Cheers

Robert


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## MediumRoastSteam

RA5040 said:


> Ha! ... I was looking at the 'My take on it post'!.
> 
> If understand your diagram correctly (and I don't think I do), the circuit looks like this:
> 
> View attachment 35264
> 
> 
> So the meter is in series (whereas in my proposed circuit it's in parallel) and it provides power to the heater either directly or via the voltage regulator, depending on the position of the switch.
> 
> I take it that there's a connection from neutral to the voltage regulator?
> 
> Have you tried running your roast with the regulator on for the full duration, including pre-heat if applicable? Any issues like power drop compared to feeding the heater direct?
> 
> Cheers
> 
> Robert


I think you understood my diagram correctly. 

I never used with the dimmer all the way, but have used for 10m continuously. I never noticed any power drops.


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## RA5040

MediumRoastSteam said:


> I think you understood my diagram correctly.


So you do have a neutral wire going to the voltage regulator?



MediumRoastSteam said:


> I never used with the dimmer all the way, but have used for 10m continuously. I never noticed any power drops.


Out of interest, why do you not use the regulator all the way? Unless it gets very hot (might need some ventilation in the box ... something to think about), or the voltage drops compared to regulator bypassed, I can't see any reason not to. After all, the Gene is still in overall control.

Cheers

Robert


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## MediumRoastSteam

RA5040 said:


> So you do have a neutral wire going to the voltage regulator?
> 
> Out of interest, why do you not use the regulator all the way? Unless it gets very hot (might need some ventilation in the box ... something to think about), or the voltage drops compared to regulator bypassed, I can't see any reason not to. After all, the Gene is still in overall control.
> 
> Cheers
> 
> Robert


I could , but I don't find necessary, specially during the drying phase.

Also, I do not have a neutral going through the voltage regulator. It's not necessary, and the input / output for the neutral wire is simply for ease of use. If you take a closer look at its PCB, it goes from one hole to the other.


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## ajohn

It's a curious thing about chinese board wiring when it's given with a board. They sometimes seem to show the triac in the live line. The logical place to put it is in the neutral line as that way the board itself remains close to ground potential which elsewhere would be the normal place to put it.

If in the neutral line and the board is marked or the circuit suggests which to use the live side would be connected to the heater and the other directly to the neutral line.

John

-


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## RA5040

MediumRoastSteam said:


> I could , but I don't find necessary, specially during the drying phase.
> 
> Also, I do not have a neutral going through the voltage regulator. It's not necessary, and the input / output for the neutral wire is simply for ease of use. If you take a closer look at its PCB, it goes from one hole to the other.


Very good ... you're right of course. I've just checked a triac circuit and it doesn't need the neutral. Also, triacs have a very low internal resistance so there should be very little voltage drop when the regulator is set to full power.

On the other hand, there probably will be a very low voltage from the regulator (by design, to make sure that motors, for example, aren't turned completely off) when the the regulator is at the minimum - not a problem.

I'll leave the switch in ... it doesn't do any harm and it's cheap.

So here's the final circuit (for now







) ... but I'll test it with a lamp before connecting up to the Gene!


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## RA5040

ajohn said:


> It's a curious thing about chinese board wiring when it's given with a board. They sometimes seem to show the triac in the live line. The logical place to put it is in the neutral line as that way the board itself remains close to ground potential which elsewhere would be the normal place to put it.
> 
> If in the neutral line and the board is marked or the circuit suggests which to use the live side would be connected to the heater and the other directly to the neutral line.
> 
> John
> 
> -


I think the triac needs to be on the live side because it will normally be triggered by a diac ... which needs something like 32V to conduct.


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## ajohn

RA5040 said:


> I think the triac needs to be on the live side because it will normally be triggered by a diac ... which needs something like 32V to conduct.


You need to think what happens voltage wise when it's on either side. Triac's and diacs are bidirectional devices so in that respect it doesn't matter. The diacs usually break down at around 30 odd volts but either way round. The triacs switch off when the current goes to near zero. That's why there is that 2% loss I mentioned - they aren't turned on again until the mains gets back up to 30v odd so there is a small loss at the start of each 1/2 cycle. Also a little one at the end of a half cycle as the triac turns off - probably ma so not worth worrying about.

I suppose i could buy a GeneCaf but I keep thinking 500g of beans







but that puts roasting some way into the future and I want to try roasting beans myself now.

Having looked at the board I may have come up with one reason it would be best to put it in the live side - the triac isn't insulated from the heatsink. I suspect that keeps it at neutral potential







always careful when thinking about AC mains circuits like this hence suspect but it very probably is the reason. If they added an insulator it would reduce the wattage rating or a bigger heat sink would have to be used.

John

-


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## RA5040

ajohn said:


> You need to think what happens voltage wise when it's on either side. Triac's and diacs are bidirectional devices so in that respect it doesn't matter. The diacs usually break down at around 30 odd volts but either way round. The triacs switch off when the current goes to near zero. That's why there is that 2% loss I mentioned - they aren't turned on again until the mains gets back up to 30v odd so there is a small loss at the start of each 1/2 cycle. Also a little one at the end of a half cycle as the triac turns off - probably ma so not worth worrying about.
> 
> I suppose i could buy a GeneCaf but I keep thinking 500g of beans
> 
> 
> 
> 
> 
> 
> 
> but that puts roasting some way into the future and I want to try roasting beans myself now.
> 
> Having looked at the board I may have come up with one reason it would be best to put it in the live side - the triac isn't insulated from the heatsink. I suspect that keeps it at neutral potential
> 
> 
> 
> 
> 
> 
> 
> always careful when thinking about AC mains circuits like this hence suspect but it very probably is the reason. If they added an insulator it would reduce the wattage rating or a bigger heat sink would have to be used.
> 
> John
> 
> -


Yes, you're right ... I keep thinking DC (not very used to AC at all). Also, it makes sense re neutral to the heatsink although there's no reason for the heatsink to be connected to anything really (maybe for safety?).

You really should get into roasting ... it's a whole new experience in sensory delight! I think it's on this forum that I read 'There's no roast like home roast'







. BTW, did you mean 500g or beans, or a hill of beans?









Robert


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## RA5040

I'll check this out myself if no one has already done so (but I suspect that DaveCUK has): what is the Gene heater switching frequency? Or does it in fact control temperature in that way, or does it turn off when (set temperature + delta1) is reached and turn back on when temperature drops to (set temperature - delta2)?

The reason I ask is that if the Gene is in fact controlling the temperature by varying the on/off cycle then as long as that is reasonably fast (maybe in the order of 10 seconds?) then there's really no advantage in doing the dimmer mod.

Robert


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## MediumRoastSteam

RA5040 said:


> I'll check this out myself if no one has already done so (but I suspect that DaveCUK has): what is the Gene heater switching frequency? Or does it in fact control temperature in that way, or does it turn off when (set temperature + delta1) is reached and turn back on when temperature drops to (set temperature - delta2)?
> 
> The reason I ask is that if the Gene is in fact controlling the temperature by varying the on/off cycle then as long as that is reasonably fast (maybe in the order of 10 seconds?) then there's really no advantage in doing the dimmer mod.
> 
> Robert


I think you answered your own question: if the Gene dimmed the heater, we wouldn't be going through all this trouble to do this mod.

The Gene switches the heater ON when the set temp is above the actual temp, and switches the heater OFF when the set temp is at or below the actual temp. As simple as that.


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## ajohn

The metal tab on power devices is usually "live" so what ever they are fastened down to is as well. Insulators are often used but these reduce the rate of heat transfer so for the same power capability a bigger heatsink is needed. Some devices are insulated but the same thing applies. You'll see thermal resistance figures quoted on data sheets in degrees C per watt. They just add up but finding out what the actual wattage is can be tricky.








500g is what I usually buy. Trouble is now I have thought about buying one I might. I reckon a home brew using convection rather than hot air would be way way cheaper but there is the problem of actually making it and probably changing it to improve it. I do have a suitable basket that should take 500g assuming the small ones that are about can take 200g plus. I did try a popcorn roaster but in my view there isn't enough control and only rather low quantities can be done in one go. 2 actually, one was the flying saucer type that fortunately I could send back. Useless, beans wouldn't turn over reliably so tended to get done on one side.

John

-


----------



## RA5040

MediumRoastSteam said:


> I think you answered your own question: if the Gene dimmed the heater, we wouldn't be going through all this trouble to do this mod.
> 
> The Gene switches the heater ON when the set temp is above the actual temp, and switches the heater OFF when the set temp is at or below the actual temp. As simple as that.


Yes, perhaps I need to do some more checking before I post!

So, I have done a check. I set the Gene to 150C for a while then at 200C and monitored the exhaust temperature with a logger (no beans in). Clearly the Gene turns on and off at +/- the set temperature, and it does so (with no beans in) at around 10 seconds (so 10 seconds on, 10 seconds off, more or less). But what is interesting is that it very closely tracks the set temperature, +/- 3 degrees.

It would seem to me that this is fine and I don't see how the mod would improve on it. Of course it will get rid of the on/off voltage to the heater, but it will replace it with a more slowly varying voltage (depending on the skill of the user) ... and so temperature.

Basically, it would seem to me that if I was controlling it I would look at the temperature, adjust the voltage down a bit if it was too high, raise the voltage a bit if it was too low ... etc. In other words I would still be getting a variation in temperature, but on a longer cycle (which isn't good, I don't think ... better from a bean mass temperature point of view to have the temperature varying quickly about the set point).

It's the same thing as a fridge or oven temperature cycling up and down: the air temperature keeps changing, but the food temperature stays quite constant, because it has mass.

So I think the mod is pointless without a feedback loop (not a human one, 'cause it's too slow). which leads one to look at a control system (Artisan?). One would then need a controllable voltage regulator.

What do you think?

Cheers

Robert


----------



## MediumRoastSteam

RA5040 said:


> Yes, perhaps I need to do some more checking before I post!
> 
> So, I have done a check. I set the Gene to 150C for a while then at 200C and monitored the exhaust temperature with a logger (no beans in). Clearly the Gene turns on and off at +/- the set temperature, and it does so (with no beans in) at around 10 seconds (so 10 seconds on, 10 seconds off more of less). But what is interesting is that it very closely tracks the set temperature, +/- 3 degrees.
> 
> It would seem to me that this is fine and I don't see how the mod would improve on it. Of course it will get rid of the on/off voltage to the heater, but it will replace it with a more slowly varying voltage (depending on the skill of the user) and so temperature. Basically, it would seem to me that if I was controlling it I would look at the temperature, adjust the voltage down a bit if it was too high, raise the voltage a bit if it was too low ... etc. In other words I would still be getting a variation in temperature, but on a longer timeframe (which isn't good, I don't think ... better from a bean mass temperature point of view to have the temperature varying quickly about the set point).
> 
> It's the same thing as a fridge or oven temperature cycling up and down: the air temperature keeps changing, but the food temperature stays constant because it has mass.
> 
> So I think the mod is pointless without a feedback loop (not a human one, cause it's too slow). which leads one to look at a control system (Artisan?). One would then need a controllable voltage regulator.
> 
> What do you think?
> 
> Cheers
> 
> Robert


I think you are going beyond the intentions of the mod, Robert.

The idea of the mod is so that:

- the element will last longer, as it doesn't flick so often;

- there would be better temp stability in the chamber;

- we can have greater control about the ramp up and/or development time.

- we can create profiles (and share) based on timing, beans and wattage, but not on the Gene temp. The Gene exhaust temp becomes redundant and can be used for guidelines only.


----------



## RA5040

ajohn said:


> The metal tab on power devices is usually "live" so what ever they are fastened down to is as well. Insulators are often used but these reduce the rate of heat transfer so for the same power capability a bigger heatsink is needed. Some devices are insulated but the same thing applies. You'll see thermal resistance figures quoted on data sheets in degrees C per watt. They just add up but finding out what the actual wattage is can be tricky.
> 
> 
> 
> 
> 
> 
> 
> 
> 500g is what I usually buy. Trouble is now I have thought about buying one I might. I reckon a home brew using convection rather than hot air would be way way cheaper but there is the problem of actually making it and probably changing it to improve it. I do have a suitable basket that should take 500g assuming the small ones that are about can take 200g plus. I did try a popcorn roaster but in my view there isn't enough control and only rather low quantities can be done in one go. 2 actually, one was the flying saucer type that fortunately I could send back. Useless, beans wouldn't turn over reliably so tended to get done on one side.
> 
> John
> 
> -


Well my advice is really not worth a hill of beans ... much less 500gms worth! But all I can say is that the Gene seems to do a great job - but I've only had it for a few weeks. What you need to do is do some creative computation using a spreadsheet. Something like this: 500gms really good quality coffee each week, cost £20. 500gms really good grean beans a week, cost £5 (you need to be a bit creative in your accounting). Weekly saving: £15. Cost of Gene: £400. ROI in 26 weeks. You see, it's really a no-brainer









Robert


----------



## Batian

You may need to adjust up you projected costs for smaller quantities of 'really good green beans'?

Great thread, thanks to all contributors.


----------



## RA5040

MediumRoastSteam said:


> I think you are going beyond the intentions of the mod, Robert.
> 
> The idea of the mod is so that:
> 
> - the element will last longer, as it doesn't flick so often;
> 
> - there would be better temp stability in the chamber;
> 
> - we can have greater control about the ramp up and/or development time.
> 
> - we can create profiles (and share) based on timing, beans and wattage, but not on the Gene temp. The Gene exhaust temp becomes redundant and can be used for guidelines only.


Some good points!

- the element will last longer, as it doesn't flick so often: yes, that's probably true

- there would be better temp stability in the chamber: not so sure about this one, for the reasons I've given

- we can have greater control about the ramp up and/or development time: yes, it would be easier to control a gradual ramp up, although it's not hard to do by gradually increasing the set temperature; not sure about better control over the development time ... I think the Gene control about the set temperature seems pretty good, and small variations in set temperature will be quickly implemented.

- we can create profiles (and share) based on timing, beans and wattage, but not on the Gene temp: could be, I don't have enough experience to comment. But from my limited experience it seems to me that there are so many variables to a roast that sharing profiles is not very useful. On the other hand .... if the parameters of the roast are carefully recorded, then reproducing a really good roast with the same beans, same ambient temperature etc., would certainly be easier. But for that, automatic recording would be very desirable I would have thought ... at least recording and plotting the exhaust temperature, and annotating things like changes to the power to the heater on the graph.

So I'm not knocking the mod ... just wondering how it can be made more useful.

Cheers

Robert


----------



## RA5040

Batian said:


> You may need to adjust up you projected costs for smaller quantities of 'really good green beans'?
> 
> Great thread, thanks to all contributors.


A little, maybe, but these are just figures for the wife


----------



## DavecUK

MediumRoastSteam said:


> I would be a pleasure DavecUK! I'll sort something out at the weekend.


If adding it to the Wiki is tricky, simple make a .pdf file and email it to me and I can add it as a downloadable document. I think the mod you did looks really good and gives people a great option.


----------



## ajohn

It does need creative accounting. 500g of well roasted beans that it seems in my case is particularly difficult to roast as I like them. Cost £10, lasts for over 2 weeks most of the time. Green beans same type where I have seen them - same cost other than on ebay. ROI - never. Bought roasted best left for say 5 days so I usually use 2nd class or buy 750 plus 250 of another type of bean and get free postage. I usually do buy one that I have never drunk before any time I order, So say I by 1kg green and cheap and i don't like it?

Obviously it's a very good idea to buy a roaster. Everyone should have one.







Maybe some one has one and realising how financially beneficial they are will sell me a used one.

On the dimmer mod running at reduced power if that's possible will extend the heating element life. The actual heating control hysteresis might improve but as it has cold air blown onto it I wouldn't expect it to make much difference. The 3 degrees is probably virtually all built in. Must admit I am surprised it's not possible to just buy the heating element - from comments made in this thread. One thing I would do is makes sure it is a 240v one.

John

-


----------



## Batian

RA5040 said:


> A little, maybe, but these are just figures for the wife


Do not forget that you will lose 13/16% of the green weight during roasting. Even more if they are roasted to an oily mass, say 20%!


----------



## RA5040

Batian said:


> Do not forget that you will lose 13/16% of the green weight during roasting. Even more if they are roasted to an oily mass, say 20%!


Yes, to be fair I don't think roasting your own coffee makes a lot of sense financially. But what has really surprised me is how really delicious the coffee I have roasted tastes and smells compared to what I considered to be excellent coffee I used to get from a very good local roaster/coffee shop. I don't think it's just the coffee though - I also got a good grinder and coffee machine and I've moved away from French Press to V60 & espresso. It's all quite an investment, but I just wish I had done it years ago (but probably could not have as the coffee just wasn't there, and nor was all of the great information on the web ... including this site!).

Getting back to the topic ...

I wonder if people who have implemented the dimmer mod could tell us a bit about how they control the Gene? For instance

- how do you go about getting a steady 150C temperature (as shown on the Gene)?

- how do you go about doing a smooth 2 minute ramp up from 150C to 200C?

- if the temperature is at 203C but you want it at 200C, how do you achieve this quickly without undershooting (and then overshooting)?

Another question is whether anyone has tried using Artisan and something like a stepper motor (or a wired or wireless voltage regulator like this one https://quasarelectronics.co.uk/Item/cebek-usbr45-computer-controlled-ac-voltage-regulator) to control the voltage regulator (to get feedback control on the system and the ability to dial in a roast profile)?

Cheers

Robert


----------



## johnealey

To answer the question on Green's:

https://www.smallbatchroasting.co.uk/product-page/india-monsooned-malabar

Buying 10kg at a time may sound like a lot when you have a gene but when you account for loss in roasting to get to your 500g a week roasted you will possibly be roasting just over 600g ( smaller amounts at a time with aged or very chaffy beans).

Using the example above £61.74 plus £7.50 next day DPD service (traceable live and you could have up to 30Kg for this price or half a sacks worth) plus you could also take advantage of their 5x100g sample bags for £2.50 (not the exotics). £6.92 a kilo to your door from an established company with quite a high turnover of beans not hanging around for years as you have seen from some of the ebay sellers (note some, you pay your money you take you chance)

if smaller quantities or more variety required the bulk buys from Bella Barista are high quality beans at a very reasonable price especially the 2kg of each variety.

Have used both, more small batch recently for the odd 10kg batchs.

Hope of help

John


----------



## RA5040

Here is a possible alternative to what we've been talking about, with the addition of PID control and monitoring:









I'm thinking of a high temperature thermistor instead of a thermocouple as it is so much easier to interface. Here is a possible unit: https://www.aliexpress.com/item/5pcs-m3x15-350Degrees-HT-NTC100K-Thermistor-High-Temperature-Sensor-Replace-K-type-thermocouple-f-3D-Printer/32828460635.html?spm=2114.search0104.3.2.501071e4AqpvHm&ws_ab_test=searchweb0_0,searchweb201602_1_10152_10151_10065_10068_10344_10342_10343_10340_10341_10696_10084_10083_10618_10304_10307_10820_10821_10302_10059_100031_524_10103_10624_10623_10622_10621_10620,searchweb201603_6,ppcSwitch_5&algo_expid=7ab4eaa9-2f05-49c3-a7c0-125ba15e0eb2-0&algo_pvid=7ab4eaa9-2f05-49c3-a7c0-125ba15e0eb2&priceBeautifyAB=0

Or a k-type thermocouple could be used with a module like this one: https://www.aliexpress.com/item/2pcs-lot-MAX6675-K-type-Thermocouple-Temperature-Sensor-Temperature-0-800-Degrees-Module-Free-Shipping-Dropshipping/1902975189.html?src=google&albslr=220878921&isdl=y&aff_short_key=UneMJZVf&source=%7Bifdyn:dyn%7D%7Bifplala%7D%7BifdbmBM&albch=DID%7D&src=google&albch=shopping&acnt=494-037-6276&isdl=y&albcp=913261809&albag=48743179105&slnk=&trgt=388120373908&plac=&crea=en1902975189&netw=g&device=c&mtctp=&aff_platform=google&gclid=CjwKCAjwg_fZBRAoEiwAppvp-TEd2IIcG1AXkHHjanPu4Ojj1AwAMCkVNYT4fPPYDbbFiIRdQ4cmahoChYAQAvD_BwE&gclsrc=aw.ds

Instead of a voltage regulator, I'm suggesting a solid state relay. The advantage is that it is very simple to control from a computer, very fast switching (typically 50ms on, 50ms off), has high isolation, and can control high power AC (or DC) loads. Here is a possible unit: https://www.aliexpress.com/item/1pcs-Free-shipping-solid-state-relay-SSR-10DA-10A-actually-3-32V-DC-TO-24-380V/32706812752.html?spm=2114.search0104.3.1.681b5435EGkXtl&ws_ab_test=searchweb0_0,searchweb201602_1_10152_10151_10065_10068_10344_10342_10343_10340_10341_10696_10084_10083_10618_10304_10307_10820_10821_10302_10059_100031_524_10103_10624_10623_10622_10621_10620,searchweb201603_6,ppcSwitch_5&algo_expid=27080f40-39ec-44b3-a127-408ad3f8ab99-0&algo_pvid=27080f40-39ec-44b3-a127-408ad3f8ab99&priceBeautifyAB=0

The Arduino can be powered directly from the laptop and it can provide the +5V, so no need for an external power supply.

The temperature would be read and scaled by the Arduino (note: more than one temperature sensor could be used ... perhaps to read the input as well as exhaust temperature, and the ambient air temperature). This would then be used to display a graph using the Arduino Serial Plotter for example (at least as a starter, before going the whole hog to Artisan).

As a (fairly) simple first step, the Arduino software would read the desired temperature set point from the laptop keyboard and do a PID control of the heater via the SSR (there's plenty of PID sample code available).

The Arduino software could read a stored roast profile from file and run it (with additional control via the keyboard ... for example 'Go to Next Step', 'Hold Current Step', 'Log 1st Crack Time' etc) ... although I suppose all of this could be done via Artisan (but I've never used it so I don't know how easy it would be to get it to do this).

Any thoughts?

Cheers

Robert


----------



## MediumRoastSteam

I would think that the only advantage would be if you have a bean mass probe on the Gene. Without it, I don't think there's much point in measuring the temperature of air escaping the chamber.


----------



## RA5040

MediumRoastSteam said:


> I would think that the only advantage would be if you have a bean mass probe on the Gene. Without it, I don't think there's much point in measuring the temperature of air escaping the chamber.


Well yes, it would certainly be nicer to have a probe inside the drum, but I'm personally not too keen to go that route because of the messiness of the job and also having circuitry and a battery in a high heat environment. Still, that certainly is an option for anyone who is happy to go that route.

This link http://roasthacker.com/?p=67 as well as this one https://coffeeforums.co.uk/showthread.php?31347-Gene-Cafe-Modified-with-Bean-Mass-Probe both show how to do this. So 2 Arduinos instead of 1.

I can't see the graphs in the second link properly so I'm not sure what the 2 curves are. In the first link, there is this graph:

View attachment 35284


This shows that the air temperature is constant from 6:00mins onwards while the bean temperature keeps rising. However, before that there appears to be a direct correlation between the two. So if the air temperature was not jammed up to max it would not be unreasonable to expect that the correlation would continue, in which case the air temperature would be a very good indication of bean temperature. Still ... this would need to be checked out. It would be great if someone who has implemented the bean mass probe in the Gene could do this!

At any rate, the circuit I'm proposing (assuming it works!) could be used without a temperature probe to control the heater in much the same way as with the dimmer mod. But you would enter the required power output (say 50%) from the laptop keyboard instead of via the potentiometer knob.

We could also add a meter like this:









And also a bypass switch, as before.

Robert


----------



## RA5040

Here's the direct equivalent of the dimmer mod, using an Arduino (actually I think the ATMeg328 chip can just be used on its own on a PCB ... there's no need for the Arduino board once the chip has been programmed ... or an Arduino Nano could be used as it's very cheap):









There are some pros and cons of this design compared to the voltage regulator design:

Pros:

- Flexible because it is programmable

- Can be extended to monitor temperatures

- Can be extended to PID control

Cons:

- Requires power supply

- Requires live feed from Gene to PSU

- Needs to be programmed

- A bit messier to mount in a box perhaps

- May not extend heater life compared to dimmer mod

I think the cost of the two options would be quite similar.

Robert


----------



## RA5040

Before launching into building a box with the dimmer mod (adapted) I've been thinking a bit about what it is that I would like to get from the mod, what I do not want to get, and how best to achieve it.

So first of all, here are the things that I like about the way the Gene works now:

- Very simple

- Appears to control the exhaust air temperature well within a range of +/-3 degrees

- Integrated system with no external boxes

- Control is right in line with the drum, so it's easy to keep an eye on both the temperature and the beans

And here are some of the things I don't like about it:

- It monitors exhaust air temperature and not bean mass temperature

- There's no way to input a roast profile

- There's no way to connect to laptop to display and log roast data

- Control of temperature could be improved

When I look at the dimmer mod it seems to me that it doesn't improve on what I like or don't like about the Gene. On the contrary, it seems to me that it will make things worse:

- External box needed

- Heater control and temperature display on separate units

- Difficult (if not impossible) to control the exhaust air temperature accurately

While the dimmer mod may possibly increase the life of the heater somewhat, it will also probably void the warranty ... so perhaps it's not such a good idea to implement it on a new Gene. And, of course there is the possibility of damaging the roaster while implementing the mod.

I think (admittedly with very little experience to back it up!) that roasting should be controlled based on temperature (and of course time, bean color, cracks etc) and not on power input to the drum. My logic for that is that I couldn't begin to think of how to bake anything in an oven based on power input to the oven ... even though an oven is a closed system. The Gene on the other hand is blowing hot air right out to the atmosphere, making it even harder.

My conclusion is that (at least for me) there is no point in implementing this mod as is. However, I do think that there would be a lot of point in implementing it if it also had temperature feedback, and if all of the control and data were in one place and close to the drum.

So I think I will probably put together a system that has temperature feedback and integrated controls. The question of where to put the temperature sensor (at the exhaust or inside the drum) I will leave for later









I think it makes a lot of sense to use an Arduino (or the ATmega328P) because it can do so much, with tremendous flexibility. Once we go in that direction then it opens up the option of having all of the controls and display on an external box; or having all of the controls and display on a laptop (or mobile phone/tablet); or both (the box controls could be automatically disabled when connected to laptop/tablet; or all of the electronics could be put inside the Gene and the controls run from the laptop/tablet (preferably wirelessly).

As for how to control the temperature: it would be quite easy to implement PID phase control using the Arduino. This would have the benefit of varying the power to the heater rather than turning it on and off (so it might improve heater life a bit). On the other hand, getting the PID parameters right for a constant temperature could be tricky. At worst one could go back to setting power low when (set point + delta) was reached and high when (set point - delta) was reached (and delta could be a low value, like 0.1 degree, say).

Anyway, these are just my thoughts and I would really appreciate input/comments (and disagreement







).

Cheers

Robert


----------



## Batian

RA5040 said:


> View attachment 35284
> 
> 
> This shows that the air temperature is constant from 6:00mins onwards while the bean temperature keeps rising. However, before that there appears to be a direct correlation between the two. So if the air temperature was not jammed up to max it would not be unreasonable to expect that the correlation would continue, in which case the air temperature would be a very good indication of bean temperature. Still ... this would need to be checked out. It would be great if someone who has implemented the bean mass probe in the Gene could do this!
> 
> Robert


This could be because the beans are absorbing more of the heat and/or the chemical reactions going on in the beans means they produce their own heat?


----------



## RA5040

Batian said:


> This could be because the beans are absorbing more of the heat and/or the chemical reactions going on in the beans means they produce their own heat?


Yes, that could well be what's happening. It's easy to see why the exhaust temperature goes flat: it's being held there. Since there is at the point that it goes flat still a substantial differential between the bean temperature and the air temperature it's reasonable to expect the bean temperature to keep rising ... even with no exothermic reactions. So on that basis it would seem that the probe is in fact measuring the bean mass temperature (or something close to it).

So looks like I may have to eat my words and put a thermocouple inside the Gene drum. Woe is me!

Cheers

Robert


----------



## MediumRoastSteam

If you find a really nice neat way of doing that, please let me know!


----------



## RA5040

MediumRoastSteam said:


> If you find a really nice neat way of doing that, please let me know!


I wish! I can't see any other way of doing it except to mount a wireless controller on the drum.

The only improvement that I can think of is to 'productise' it: put everything onto a single PCB ... and maybe mold in an epoxy resin with an air gap around the components (after programming the chip ... or leave the ISP pins showing). But it would only be worth the trouble and cost of doing this if there was some interest ... probably not worth it for a one-off.


----------



## RA5040

I've just done a couple of roasts with an oven thermometer inside the drum. I videoed the roasts so that I was able to view the videos and write down the 'BMT' (the oven thermometer reading) and the Exhaust Temperature (Gene reading).

Here's a short video clip to show where I put the thermometer: http://www.irelandupclose.com/customer/Videos/C2-Clip.mp4

And here is a graph of the temperatures:









I've shifted the BMT curve to the left by about 30 seconds to compensate for the rather slow meter.

The other roast was pretty much identical.

The dip at around 6mins is because I set the temperature to 200C and gave it 1min when the exhaust temperature reached 200 (you can see the Gene turning on and off the heater), then set the temperature to 245 and left it there for the rest of the roast.

The exhaust temperature never reached 245 and neither did the meter ... but both got to 240.

The graph does sort of confirm the one I posted earlier. But I need to digest it a bit to see if it's really worth putting a probe inside the drum or whether the exhaust air temperature would be good enough. The oven thermometer does give an idea of what's happening, but it's probably too slow to let us see the finer points (if any).

BTW ... having had a good look at the drum, what I would do if I was putting a thermocouple in to it would be to locate it where I have the oven thermometer. I would drill through the lid (I've checked ... easy to do) and fix the thermocouple to it so that when the lid was opened the thermocouple would come out with it, leaving the inside of the drum unencumbered for cleaning/washing. Doing it this way also means that a second thermocouple can be placed at the exhaust (inside top of lid) so that the exhaust air temperature could be monitored too.

Thoughts/observations/suggestions most welcome!

Cheers

Robert


----------



## MediumRoastSteam

RA5040 said:


> I've just done a couple of roasts with an oven thermometer inside the drum. I videoed the roasts so that I was able to view the videos and write down the 'BMT' (the oven thermometer reading) and the Exhaust Temperature (Gene reading).
> 
> Here's a short video clip to show where I put the thermometer: http://www.irelandupclose.com/customer/Videos/C2-Clip.mp4
> 
> And here is a graph of the temperatures:
> 
> View attachment 35341
> 
> 
> I've shifted the BMT curve to the left by about 30 seconds to compensate for the rather slow meter.
> 
> The other roast was pretty much identical.
> 
> The dip at around 6mins is because I set the temperature to 200C and gave it 1min when the exhaust temperature reached 200 (you can see the Gene turning on and off the heater), then set the temperature to 245 and left it there for the rest of the roast.
> 
> The exhaust temperature never reached 245 and neither did the meter ... but both got to 240.
> 
> The graph does sort of confirm the one I posted earlier. But I need to digest it a bit to see if it's really worth putting a probe inside the drum or whether the exhaust air temperature would be good enough. The oven thermometer does give an idea of what's happening, but it's probably too slow to let us see the finer points (if any).
> 
> BTW ... having had a good look at the drum, what I would do if I was putting a thermocouple in to it would be to locate it where I have the oven thermometer. I would drill through the lid (I've checked ... easy to do) and fix the thermocouple to it so that when the lid was opened the thermocouple would come out with it, leaving the inside of the drum unencumbered for cleaning/washing. Doing it this way also means that a second thermocouple can be placed at the exhaust (inside top of lid) so that the exhaust air temperature could be monitored too.
> 
> Thoughts/observations/suggestions most welcome!
> 
> Cheers
> 
> Robert


Interesting. Something I wondered how well that would work too, so thanks for sharing.

There's another member here who did the bean mass temp mod. If I remember correctly from some of his posts, BMT is nowhere near as the Gene exhaust temp. I'm wondering whether your thermometer is registering a lot of the air temp inside the drum as opposed to the bean mass temp itself.


----------



## RA5040

Yes, the oven thermometer is too big and too slow. It must be measuring a good bit of the air as well as the beans.

Unfortunately any probe will also measure air temperature because there's nowhere that's always covered by beans ... Another thing to factor in


----------



## Batian

That oven thermometer is a fair old lump in there. I wonder how much heat that absorbs and retains at cool down.

Also, how does it effect the air-flow?

Re your comment on being able to see the heater turning on and off:

You should also be able to hear a click (from the exhaust end of the machine?) as it turns off? Saves getting a stiff neck!

In answer to your Q about the exhaust temp reading being good enough:

It is not ideal, and I admire and understand your desire to explore improvements to a very basic roaster. Over many years hundreds of Gene users have learned how to roast good roasts by using it with out to much trouble!

It's an acquired knack that is obtained with just a little practise. It is also knowledge that will hold good if a Gene user upgrades at some point.

It is the art of predicting the heater on/off along with ROR/ROF in temp, and when a temp increase/decrease is needed. Plus what you can see and smell and hear.

More art of roasting (by the seat of your pants), than science roasting?


----------



## MediumRoastSteam

RA5040 said:


> Yes, the oven thermometer is too big and too slow. It must be measuring a good bit of the air as well as the beans.
> 
> Unfortunately any probe will also measure air temperature because there's nowhere that's always covered by beans ... Another thing to factor in


Yes. I've read that the trick is to measure the temp of the probe when it's covered by beans. The software can then be programmed cleverly to filter out other measurements.


----------



## RA5040

Yes, the oven thermometer is more for fun than anything else ... no intention of leaving it in there!

I find that I get really good roasts with the Gene and I'm really not at all sure that trying to make it more scientific would make that much difference. But until one tries one can't know!

I would like to be able to see the BMT and exhaust temperature as a real-time graph with all of the controls in the same place (so on a tablet or laptop for example). I would imagine that with this sort of information, and the ability to use stored profiles and accurately control the heater that the whole business should be less hit and miss, especially towards the end of the roast when so much is happening so quickly. And I do think that this is quite achievable ... which would then make the Gene quite a sophisticated roaster (not that I would know a sophisticated roaster if I met one!).

But at the end of the day I suspect that, like with any form of cooking, that experience and feel probably counts for more than measurements. Having said that, a good oven or hob does make things a lot easier - even though one can manage with less good equipment.


----------



## RA5040

That's a brilliant suggestion! It would be easy enough to detect when the beans are fully covered and take the reading at that point. Would need a fast-acting thermocouple.


----------



## Batian

RA5040 said:


> That's a brilliant suggestion! It would be easy enough to detect when the beans are fully covered and take the reading at that point. Would need a fast-acting thermocouple.


Hasi has got a thread running where he is doing a similar thing with an Amazon. He is using some type of probe that reacts much quicker than a K type---but he is running into (temporary) problems. Look it up and liaise?


----------



## RA5040

Batian said:


> Hasi has got a thread running where he is doing a similar thing with an Amazon. He is using some type of probe that reacts much quicker than a K type---but he is running into (temporary) problems. Look it up and liaise?


Thank you!

I had a look for his thread but I couldn't find it so I sent him a PM. Hopefully he has some useful info.

The drum rotates in about 7 secs, so I would need a thermocouple + circuitry to take a stable measurement for a temperature change of 30C, say (difference between bean and air temperature) within 3 secs. That shouldn't be much of a problem, but it's very had to get hard info on the sensors (probably need to talk to the manufacturer). One option would be a thermistor ... and I know you can get these with a 1 sec response time, so the reading should be pretty good in 3 secs for that sort of temperature change.

If this works, it would be really great because the one sensor could measure both air and bean temperature (with air temperature measured just when the beans cover the sensor and the bean temperature measured just when the sensor is back in air). Of course this would mean detecting the position of the drum but that should be fairly easy, with something like a Hall-effect sensor.

At this point I'm beginning to think the best thing to do would be to throw out all of the Gene electronics and put in my own









Cheers

Robert


----------



## Batian

RA5040 said:


> Thank you!
> 
> I had a look for his thread but I couldn't find it so I sent him a PM. Hopefully he has some useful info.
> 
> Robert


Around here:

https://coffeeforums.co.uk/showthread.php?38351-Dalian-Amazon-Experiences&p=607953#post607953


----------



## RA5040

I have another possible solution to the probe problem. As the probe can be placed in a location that is in air about half of the time and in the beans for half of the time, the temperature measured (say BET) should be an average of the bean temperature (BMT) and air temperature (ET). If we use two probes to measure BET and ET then we can work out BMT = 2BET - ET.

As it's not so easy to find a spot in the drum that isn't covered by beans for part of the time, probably the best place for the ET probe would be inside the lid in the outlet stream.

The single fast-response probe would certainly be a more elegant solution, but if the response time is too slow then this would be an option that should work.

But even if the single probe does work it may be worth putting in the 2nd probe as it can be used to validate that the single probe gives an accurate BMT and ET reading.

can

Cheers

Robert


----------



## Rob1

One single probe: The lowest temperature reading is the bean mass; the highest is the air temp. Readings can be taken and stored rapidly before the lowest/highest is sent to the computer every second or so.

Earlier you asked how users go about maintaining a temp of say 150c or achieve a steady ramp from there to 200c. My question is why would you want to do that? You're applying energy to the beans, not attempting to maintain a set exhaust air temp. The temp of the air in the chamber is hotter towards the heating element than it is at the end of the chaff collector. The dimmer mod reduces this difference allowing more control and consistency over chamber temperature. As you can see the beans changing colour you can quite accurately determine temperature and make changes based on that rather than a figure that has very little relation with the bean temperature (a relationship that continues to change throughout the roast).

There's an entire documentation and code available at the roasthacker site you linked to for a project exactly like the one you're describing here (computer control of the gene).


----------



## RA5040

Rob1 said:


> One single probe: The lowest temperature reading is the bean mass; the highest is the air temp. Readings can be taken and stored rapidly before the lowest/highest is sent to the computer every second or so.


A single probe would definitely be preferable. Do you have a thermocouple that can react in that timeframe? It would need to be able to get a stable reading within 3 secs, which is very fast. Bear in mind that if the response time of the thermocouple is 1 sec, say, that is normally only to around 64% of the final temperature, so a stable reading would take 5 seconds.



Rob1 said:


> Earlier you asked how users go about maintaining a temp of say 150c or achieve a steady ramp from there to 200c. My question is why would you want to do that? You're applying energy to the beans, not attempting to maintain a set exhaust air temp. The temp of the air in the chamber is hotter towards the heating element than it is at the end of the chaff collector. The dimmer mod reduces this difference allowing more control and consistency over chamber temperature. As you can see the beans changing colour you can quite accurately determine temperature and make changes based on that rather than a figure that has very little relation with the bean temperature (a relationship that continues to change throughout the roast).


I don't want to control the roast based on the exhaust temperature ... but without measuring the bean temperature it's the only available temperature measurement on the Gene. I know that with the dimmer mod that you can see the energy input, but energy input is a bit meaningless unless you also know the energy loss through conduction, radiation and, especially, exhaust, as well as ambient air temperature and rate of air intake. And even if you did have these figures, computing an actual heat transfer to the beans is complex and doesn't easily translate to a bean temperature (which is the critical thing after all).

With the Gene control, the air temperature drops and rises by several degrees when the Gene is trying to hold the temperature at a set value. One advantage of the dimmer mod is that this cycling up and down should be preventable ... if the operator is able to do so (which I'm not at all sure that he/she would be able to do). Which is why I asked the question, which boils down to how well can you control the temperature to a set value.

But if you can accurately tell the bean temperature from its colour then that's pretty cool. How do you do that?

Robert


----------



## Rob1

RA5040 said:


> A single probe would definitely be preferable. Do you have a thermocouple that can react in that timeframe? It would need to be able to get a stable reading within 3 secs, which is very fast. Bear in mind that if the response time of the thermocouple is 1 sec, say, that is normally only to around 64% of the final temperature, so a stable reading would take 5 seconds.


You'll never get a stable reading as the temperature is constantly increasing (or not if you mess up). Another thing to consider is the thermocouple accuracy will not be the same at 50c as it is at 250c or even 150c. It isn't the accuracy that is important so much as consistency. For example having a reading of 220c that correlates to increased smoke production and the very first outlying pops of first crack is just as good as knowing the temp is actually 205c. So consistently reading 64% of the final temperature is just as useful as 100% so long as you know what the actual temp is. Yet another thing to consider is the thermocouple is not measuring internal bean temperature, only the surface temp of the bean.

To answer your question, yes I have a thermocouple that responds quickly enough. I've linked to it in the thread I created that you linked to which is also linked in my signature.



> I don't want to control the roast based on the exhaust temperature ... but without measuring the bean temperature it's the only available temperature measurement on the Gene. I know that with the dimmer mod that you can see the energy input, but energy input is a bit meaningless unless you also know the energy loss through conduction, radiation and, especially, exhaust, as well as ambient air temperature and rate of air intake. And even if you did have these figures, computing an actual heat transfer to the beans is complex and doesn't easily translate to a bean temperature (which is the critical thing after all).


Complex, unnecessary and impossible to calculate regardless of how you try to measure things. When roasting you need to judge the rate of rise (which can be done via sight in the gene) which is easily done with a thermocouple spitting out a temperature at a consistent rate after a consistent time being exposed to the bean mass in a consistent location.



> With the Gene control, the air temperature drops and rises by several degrees when the Gene is trying to hold the temperature at a set value. One advantage of the dimmer mod is that this cycling up and down should be preventable ... if the operator is able to do so (which I'm not at all sure that he/she would be able to do). Which is why I asked the question, which boils down to how well can you control the temperature to a set value.
> 
> But if you can accurately tell the bean temperature from its colour then that's pretty cool. How do you do that?
> 
> Robert


The operator is able to control energy input. it is possible to maintain a set temp with the mod but the power needed with an empty drum is different to when the drum is full. I did briefly experiment with trying to correlate watts to temperature with a full batch but the power would drop to the point the gene would throw out an error and shut down. The mod doesn't allow you to prevent cycling up and down but it does minimise it and allow a more consistent chamber temperature=more consistent roast.

Google using sight to determine degree of roast from sweet maria's. Bear in mind you'll be making changes based on the rate of rise (ballpark) so knowing the precise temp of the beans at all times isn't necessary. It does get easier with a thermocouple but the real use is in repeating the same roast, not that it's impossible without the probe it's just a lot easier. I did a pretty good job without it on my lasts two roasts but probably only because of the experience gained from using it.


----------



## RA5040

Is this your project: http://roasthacker.com/?p=552?

If so, thank you for it ... I need to have a good look at it again and also digest what you have written here when I have a bit of time later today.

Cheers

Robert


----------



## Rob1

No the thread on this forum details how I copied the project and sourced all the parts from the UK.


----------



## RA5040

OK, well your advice would be most welcome!

I have a couple of questions about your project:

- are you still using the bean mass probe mod and if so have you had any temperature issues with the circuitry and/or battery?

- on this post https://coffeeforums.co.uk/showthread.php?31347&p=422130#post422130, what are the different curves? I can't read the text on the graphs because it is very small



Rob1 said:


> You'll never get a stable reading as the temperature is constantly increasing (or not if you mess up). Another thing to consider is the thermocouple accuracy will not be the same at 50c as it is at 250c or even 150c. It isn't the accuracy that is important so much as consistency. For example having a reading of 220c that correlates to increased smoke production and the very first outlying pops of first crack is just as good as knowing the temp is actually 205c. So consistently reading 64% of the final temperature is just as useful as 100% so long as you know what the actual temp is. Yet another thing to consider is the thermocouple is not measuring internal bean temperature, only the surface temp of the bean.
> 
> To answer your question, yes I have a thermocouple that responds quickly enough. I've linked to it in the thread I created that you linked to which is also linked in my signature.


Of course the temperature is changing so the thermocouple will never give a fixed reading. However the air and bean temperatures are not changing much at all in a 3 second time period, and that is the time period that is needed if a single probe is to measure both the air and bean temperatures. Up to a point a 64% reading is better than nothing, but it's really not great because the two temperatures would be averaging. Having said that, a probe with a 1sec response would be fine because it would give probably about 85% of actual temperature in 3 secs.

But I totally accept your point regarding consistency: the actual value is not so important whereas repeatability and consistency are.

I've had a look at the roasthacker thermocouple and it's supplied by Adafruit. I see no response time specification on the Adafruit site. Have you tested your thermocouple to see how fast it responds to a step change? I would certainly prefer to use a single probe ... but if that's not possible then two slow thermocouples or RTDs would do the job I think.



Rob1 said:


> Complex, unnecessary and impossible to calculate regardless of how you try to measure things. When roasting you need to judge the rate of rise (which can be done via sight in the gene) which is easily done with a thermocouple spitting out a temperature at a consistent rate after a consistent time being exposed to the bean mass in a consistent location.


Exactly, which is why I think a BMT reading is necessary if one is going to get the full benefit of the dimmer mod (or some variant of it): if one has a BMT reading and a 'dimmer mod' then it's straightforward (but not necessarily simple to implement!) a PID control ... in which case smooth control of the bean/air temperatures should be possible.

Thanks

Robert


----------



## Rob1

I'm still using it and I've never had any issues due to the heat. I've not measured it but it can't be far above 60c if it is even near at all (you can comfortably hold your hand close to the battery and comfortably hold the battery after roasting). I've been doing one roast at a time mostly but have recently switched to two batches and I haven't noticed the battery getting any hotter in that time.

No, I haven't tested the thermocouple's response time but I seem to remember it being listed as one second (the wire is exposed). I didn't even bother calibrating it to be honest, or more accurately I forgot in my excitement/desperation to get the project finished, but it seems to be accurate and is definitely consistent.







https://drive.google.com/file/d/1EpVcSWKlkYaE9ufrMmigFQYO3wTiWWnq/view?usp=sharing







https://drive.google.com/file/d/1KOyDJbin54clW9W4I5OKzePk6_MRn4PO/view?usp=sharing

The first image is without any smoothing. The temperature fluctuation is in part due to inconsistent temps through the bean mass (obviously expected) but it could also be something to do with the coding. I've never had a reason to really try to correct it as it wouldn't really effect how useful I find the information.

This is the first roast I recorded and I kept it going through the cooling cycle to see how effective it is. The two temp curves are not actually BT and ET though, they are just lowest and highest. Logically during roasting the lowest temperature is going to be the beans but during cooling the lowest temperature will be the air. It's interesting there's no crossover between the two readings. I think I have a few records from when the heating element was switching on and off for 5 seconds around a set temperature and it showed a clear drop in bean temperature in that time.


----------



## RA5040

Rob1 said:


> I'm still using it and I've never had any issues due to the heat. I've not measured it but it can't be far above 60c if it is even near at all (you can comfortably hold your hand close to the battery and comfortably hold the battery after roasting). I've been doing one roast at a time mostly but have recently switched to two batches and I haven't noticed the battery getting any hotter in that time.
> 
> No, I haven't tested the thermocouple's response time but I seem to remember it being listed as one second (the wire is exposed). I didn't even bother calibrating it to be honest, or more accurately I forgot in my excitement/desperation to get the project finished, but it seems to be accurate and is definitely consistent.
> 
> View attachment 35420
> https://drive.google.com/file/d/1EpVcSWKlkYaE9ufrMmigFQYO3wTiWWnq/view?usp=sharing
> 
> View attachment 35421
> https://drive.google.com/file/d/1KOyDJbin54clW9W4I5OKzePk6_MRn4PO/view?usp=sharing
> 
> The first image is without any smoothing. The temperature fluctuation is in part due to inconsistent temps through the bean mass (obviously expected) but it could also be something to do with the coding. I've never had a reason to really try to correct it as it wouldn't really effect how useful I find the information.
> 
> This is the first roast I recorded and I kept it going through the cooling cycle to see how effective it is. The two temp curves are not actually BT and ET though, they are just lowest and highest. Logically during roasting the lowest temperature is going to be the beans but during cooling the lowest temperature will be the air. It's interesting there's no crossover between the two readings. I think I have a few records from when the heating element was switching on and off for 5 seconds around a set temperature and it showed a clear drop in bean temperature in that time.


Many thanks ... I see what you're doing now. I take it the 3rd curve is the ROR? I wonder why it's jumping around (on the unsmoothed graph)? Also, why does it start to go up again at the end of the cooling cycle?

I'm glad to hear you find the temperature of the circuit & battery to be OK. I had concluded that it wasn't OK and some form of cooling would be needed (probably a small fan). But if it isn't necessary then so much the better.

I'm beginning to think that it might be an idea to replace the Gene electronics ... it may sound a bit crazy, but there really isn't much to it, and fitting the dimmer mod at the output of the Gene board isn't the best. It would be nice to have a fully integrated system.

Thanks for your help,

Robert


----------



## MediumRoastSteam

RA5040 said:


> Many thanks ... I see what you're doing now. I take it the 3rd curve is the ROR? I wonder why it's jumping around (on the unsmoothed graph)? Also, why does it start to go up again at the end of the cooling cycle?
> 
> I'm glad to hear you find the temperature of the circuit & battery to be OK. I had concluded that it wasn't OK and some form of cooling would be needed (probably a small fan). But if it isn't necessary then so much the better.
> 
> I'm beginning to think that it might be an idea to replace the Gene electronics ... it may sound a bit crazy, but there really isn't much to it, and fitting the dimmer mod at the output of the Gene board isn't the best. It would be nice to have a fully integrated system.
> 
> Thanks for your help,
> 
> Robert


There's a German man who completely replaced the Gene electronics .... let me see if I can find the video


----------



## RA5040

MediumRoastSteam said:


> There's a German man who completely replaced the Gene electronics .... let me see if I can find the video


That would be very cool! Why reinvent the wheel?


----------



## MediumRoastSteam

RA5040 said:


> That would be very cool! Why reinvent the wheel?


I *THINK* it was this one:


----------



## Rob1

If you look at the graph you'll get your answer. It's cooling the beans at more than -20c a minute for three minutes and then you see the ROR go up because it goes up from -20 to -5 towards the end of the cooling cycle.

The ROR goes up and down because as described the temp goes up and down. The temp goes up and down likely because the bean mass isn't a completely consistent temperature and therefore the ROR calculation will vary too.

The roasthacker site details replacing the gene electronics entirely.


----------



## RA5040

MediumRoastSteam said:


> I *THINK* it was this one:


Obrigado!

I've followed through and gotten to his project file, here: https://coffeesnobs.com.au/attachments/home-roasting-tips-tricks-ideas/18284d1517846817-gene-automation-mod-lcd-version-gene-automation-mod-manual.zip

If you add the BMT probe to this and change from on/off control to phase-angle control you would have quite a machine!

Cheers

Robert


----------



## Rob1

Actually to modify my answer I'm not sure why the peaks and lows for the ROR are so violent. They don't seem to relate to the recorded temps at all. I have wondered if it varies between recording the ror of the high value and the low value, given the variation becomes less severe as the roast progresses that might make sense as the two temperatures come closer together. It's likely due to the coding and the way I'm sending the information from the thermocouple to the logger. I might just make it simple and have it spit out the BT only to see if that makes a difference.


----------



## RA5040

Rob1 said:


> If you look at the graph you'll get your answer. It's cooling the beans at more than -20c a minute for three minutes and then you see the ROR go up because it goes up from -20 to -5 towards the end of the cooling cycle.


Yes, I can see that the rate of cooling is reducing ... however as long as the temperature is dropping, the rate of rise should be negative. It should be computed as (current reading - last reading)/(time period), so as long as the current reading is less than the last reading the ROR should be -ve.



Rob1 said:


> The ROR goes up and down because as described the temp goes up and down. The temp goes up and down likely because the bean mass isn't a completely consistent temperature and therefore the ROR calculation will vary too.


Yes, the bean mass temperature not being consistent could be a reason. Another reason could be that with a single probe it will be very difficult to get a reading of both the air and bean temperatures. A slight variation in reading is all that's needed to make the differential very jaggedy. It would probably be better to use a weighted average of the last 3 readings, say (or just use the smoothed curve)



Rob1 said:


> The roasthacker site details replacing the gene electronics entirely.


Thanks for that ... I'll see if I can find the link.

Cheers

Robert


----------



## Rob1

RA5040 said:


> Yes, I can see that the rate of cooling is reducing ... however as long as the temperature is dropping, the rate of rise should be negative. It should be computed as (current reading - last reading)/(time period), so as long as the current reading is less than the last reading the ROR should be -ve.
> 
> Yes, the bean mass temperature not being consistent could be a reason. Another reason could be that with a single probe it will be very difficult to get a reading of both the air and bean temperatures. A slight variation in reading is all that's needed to make the differential very jaggedy. It would probably be better to use a weighted average of the last 3 readings, say (or just use the smoothed curve)
> 
> Thanks for that ... I'll see if I can find the link.
> 
> Cheers
> 
> Robert


The graph shows the cooling cycle ror going from below -20 up to -5 until it stops...

In my logger software there's an option to only plot the bt curve so I'll try that before altering the code. From memory I think I've got the code logging 10 times per second before the calculations are performed and it releases the numbers once per second, but the plotting software only plots once every three seconds. I think I might have to revisit the code to see what I can do. Without replacing the gene electronics it isn't an option to synchronise the readings with the drum rotation which would make logging a lot easier.


----------



## RA5040

Rob1 said:


> The graph shows the cooling cycle ror going from below -20 up to -5 until it stops...
> 
> In my logger software there's an option to only plot the bt curve so I'll try that before altering the code. From memory I think I've got the code logging 10 times per second before the calculations are performed and it releases the numbers once per second, but the plotting software only plots once every three seconds. I think I might have to revisit the code to see what I can do. Without replacing the gene electronics it isn't an option to synchronise the readings with the drum rotation which would make logging a lot easier.


What you could do is to put a hall-effect sensor on your circuit, with a magnet on a fixed surface of the Gene - that would give you a fixed position of the drum for every rotation.


----------



## RA5040

Here's a sketch of what I intend to do ... that is, replace the Gene electronics completely. It seems like the logical thing to do, even though it's a bit more work (but not much more than doing the power mod & adding a BMT sensor).

The advantages of replacing the electronics are that it gives additional control/information: for instance the inlet and exhaust thermocouples and the drum position sensor become available; also bypassing the power to the heater is no longer a safety issue as the new electronics can shut down the system if temperatures go too high (anywhere).









I will probably end up using one of the Arduino/Adafruit boards but as it will be necessary to build a circuit board it may end up not being more difficult to use the microcontroller directly.

Robert


----------



## Simon_S

@Rob1 just curious what are you using to produce them graphs mate?

I've been using the adafruit io dashboard as a visual cue on my laptop & the coffee roaster pro app to log roasts using the mqtt protocol sent from adafruit....


----------



## Rob1

http://www.roastlogger.co.uk/coffee/roastlogger/roastlogger.htm

It works with a serial port connection so the first version using the adafruit bluefruit ez link works with it, I'm not sure about MQTT but you might be able to get create a virtual serial device to pass the info along to the software, or you might have to pass the information through a device actually connected to a serial port/usb.


----------



## Simon_S

Rob1 said:


> http://www.roastlogger.co.uk/coffee/roastlogger/roastlogger.htm
> 
> It works with a serial port connection so the first version using the adafruit bluefruit ez link works with it, I'm not sure about MQTT but you might be able to get create a virtual serial device to pass the info along to the software, or you might have to pass the information through a device actually connected to a serial port/usb.


Thanks mate, I did have a look at that but couldn't figure a way to get the mqtt data across, shame because it sure looks pretty.....

Anyone else know how that may be implemented?


----------



## Rob1

I think the only way is to pass it through an arduino or similar device attached via the USB or serial port.


----------



## Batian

Well out of my depth here, but would software from here be of use or adaptable?

Scroll down.

http://www.yoctopuce.com/EN/products/usb-environmental-sensors/yocto-thermocouple


----------



## RA5040

Simon_S said:


> Thanks mate, I did have a look at that but couldn't figure a way to get the mqtt data across, shame because it sure looks pretty.....
> 
> Anyone else know how that may be implemented?


How about using JFreeChart? Open source for Mac, Windows, Linux.


----------



## Simon_S

Batian said:


> Well out of my depth here.


Same as that!

Had a read of the link, I don't think that'll work for my needs, but would happily stand corrected.


----------



## Simon_S

RA5040 said:


> How about using JFreeChart? Open source for Mac, Windows, Linux.


Thanks for that Robert, looks interesting. Do you think it would allow for mqtt data to be sent to a serial port or is it designed to simply create a chart based on said data?

S.


----------



## RA5040

Simon_S said:


> Thanks for that Robert, looks interesting. Do you think it would allow for mqtt data to be sent to a serial port or is it designed to simply create a chart based on said data?
> 
> S.


JFreeChart is normally used from within a Java app so there's no reason why MQTT data can't be used alongside it. I'll have a look as I also need something like this, and unfortunately roastlogger seems a bit closed (although it may be possible to adapt it? Rob1 would know more about this than me).


----------



## Simon_S

Rob1 said:


> I think the only way is to pass it through an arduino or similar device attached via the USB or serial port.


Hmmmm, where to begin with that!?

I did struggle with an answer to this last year when I first stumbled upon roast logger.... I must also admit the bean temp hack was my first ever adventure down the programming wormhole!


----------



## RA5040

Here is a really excellent tutorial on using JFreeChart with a connection to an Arduino.

As you can see, it would be very easy to add additional temperature sensors, set point for temperature PID (or implement the PID in Java) etc. It's certainly an alternative to roastlogger, and one that we would have complete control over.

Robert


----------



## RA5040

And this seems to fit the bill for MQTT (but I've only had a quick scan through







): https://www.hivemq.com/blog/how-to-get-started-with-mqtt

It wouldn't seem too hard to fit this and the JFreeChart together for a pretty nice system.

But I can't quite see why you would want to use MQTT to control a Gene, to be honest ... I think USB or bluetooth would be preferable (and simpler!).

Robert


----------



## Simon_S

RA5040 said:


> But I can't quite see why you would want to use MQTT to control a Gene, to be honest ... I think USB or bluetooth would be preferable (and simpler!).
> 
> Robert


I'm not looking to control my Gene via mqtt, the bean mass probe I installed outputs its data using the mqtt protocol.


----------



## mattpitts74

I've recently got a Gene Cafe and roasted a couple of batches so far. But I imagine in the long term I will end up doing the dimmer mod. But I see that you guys I have evolved it into something a bit more techie.

I'm wondering if you have had enough time roasting with these mods to know if they are more worth while than the original dimmer mod?

I'm guessing that having the numbers could be more helpful for making things more repeatable?

Would you recommend the original mod or your versions with the voltage regulator and screens? Do you think this mod makes enough of a difference to make it worth while?

Did you end up using this parts list and wiring?



RA5040 said:


> I would appreciate it if someone would check out this circuit for the power mod:
> 
> View attachment 35259
> 
> 
> So I'm proposing to:
> 
> - disconnect both of the heater connections to the Gene board sockets
> 
> - connect the heater live socket on the Gene board either to the voltage regulator, or directly back to the heater via the switch
> 
> - connect the heater neutral socket on the Gene board to the voltage regulator and loop it back to the heater
> 
> - connect the voltage/current/power meter across the heater
> 
> - pass the heater live wire through the current sensing torroid to measure current and power
> 
> I'm proposing to use the following parts:
> 
> - Voltage Regulator: https://www.amazon.co.uk/gp/product/B0154I3ZUY/ref=ox_sc_act_title_3?smid=A38I4T5NBLJJJ3&psc=1
> 
> - Meter: https://www.amazon.co.uk/gp/product/B01F37GFE4/ref=ox_sc_act_title_2?smid=A38I4T5NBLJJJ3&psc=1
> 
> - Switch: https://www.amazon.co.uk/gp/product/B00EZI4B9O/ref=ox_sc_act_title_1?smid=A3P5ROKL5A1OLE&psc=1
> 
> - Box: https://www.amazon.co.uk/gp/product/B071GRDPZG/ref=ox_sc_act_title_1?smid=A1JQD8FFNWUAB1&psc=1
> 
> I'm getting everything from Amazon as it's all free shipping and the prices are pretty good (also great for returns if there's a problem!).
> 
> I hope that makes sense and is at least a bit correct
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Robert


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## RA5040

Simon_S said:


> I'm not looking to control my Gene via mqtt, the bean mass probe I installed outputs its data using the mqtt protocol.


OK, well it should be quite easy to connect to the Gene over MQTT in Java, and it is easy to do up a Java GUI with graphs using JFreeChart. Here's the result of a bit of messing with Java/JFreeChart, with simulated values in this case:









What I'm planning to do is to develop this app so that it has good functionality (for example, being able to store a roast profile and use it, as is or modified, to run a roast). I will then install Ubuntu on an old Android tablet I have and run the app on that (I don't particularly want to use my Apple laptop, but that would also be an option). I will use USB or bluetooth, but I don't see any reason why MQTT would not be fine (Java has MQTT libraries).

Cheers

Robert


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## RA5040

mattpitts74 said:


> I've recently got a Gene Cafe and roasted a couple of batches so far. But I imagine in the long term I will end up doing the dimmer mod. But I see that you guys I have evolved it into something a bit more techie.
> 
> I'm wondering if you have had enough time roasting with these mods to know if they are more worth while than the original dimmer mod?
> 
> I'm guessing that having the numbers could be more helpful for making things more repeatable?
> 
> Would you recommend the original mod or your versions with the voltage regulator and screens? Do you think this mod makes enough of a difference to make it worth while?
> 
> Did you end up using this parts list and wiring?


Not having implemented any of this yet, my input is of debatable value. Having said that, I have thought about it all quite a bit, and my own feeling is that the dimmer mod on its own has limited value (I wouldn't be bothered doing it). I think the BMT probe is probably worth doing as it would give a useful graphical view of the roast and would help to run roasts based on stored results (at least to some extent).

But I do think that the best approach is to replace the Gene electronics (with or without the BMT probe). This would give complete control over the Gene, it would allow both the input air temperature and exhaust air temperature to be plotted and stored, so that roast profiles could be stored and new roasts run on these profiles; and the Gene heater could be controlled much more accurately with PID phase control. The drum position would be known as the Gene already has a hall-effect sensor, so if a BMT probe was added (which would certainly be a good addition) it would be easier to get a good BMT reading (since knowing the drum position would help in taking the BMT reading). Then the environment temperature could be worked out, perhaps as an average of the input and exhaust air temperatures, and this would allow for a more accurate computation of the bean mass temperature.

I've had a look at the Gene electronics and there really isn't much to it: motor, fan and heater control and that's about it.

Robert


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## mattpitts74

RA5040 said:


> Not having implemented any of this yet, my input is of debatable value. Having said that, I have thought about it all quite a bit, and my own feeling is that the dimmer mod on its own has limited value (I wouldn't be bothered doing it). I think the BMT probe is probably worth doing as it would give a useful graphical view of the roast and would help to run roasts based on stored results (at least to some extent).
> 
> But I do think that the best approach is to replace the Gene electronics (with or without the BMT probe). This would give complete control over the Gene, it would allow both the input air temperature and exhaust air temperature to be plotted and stored, so that roast profiles could be stored and new roasts run on these profiles; and the Gene heater could be controlled much more accurately with PID phase control. The drum position would be known as the Gene already has a hall-effect sensor, so if a BMT probe was added (which would certainly be a good addition) it would be easier to get a good BMT reading (since knowing the drum position would help in taking the BMT reading). Then the environment temperature could be worked out, perhaps as an average of the input and exhaust air temperatures, and this would allow for a more accurate computation of the bean mass temperature.
> 
> I've had a look at the Gene electronics and there really isn't much to it: motor, fan and heater control and that's about it.
> 
> Robert


Hi Robert,

Thanks for your thoughts, its early days for me with the Gene, so I will hang fire and keep an eye on what you and others are doing, I've played around with Arduino's in home automation, but I'm no expert, but anything is possible with the right coding.

I did come across this https://github.com/AndersKaloer/GeneCafeMod, which I suspect you have already seen? looks interesting.


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## RA5040

mattpitts74 said:


> Hi Robert,
> 
> Thanks for your thoughts, its early days for me with the Gene, so I will hang fire and keep an eye on what you and others are doing, I've played around with Arduino's in home automation, but I'm no expert, but anything is possible with the right coding.
> 
> I did come across this https://github.com/AndersKaloer/GeneCafeMod, which I suspect you have already seen? looks interesting.


Hi, yes, several people have done this ... nothing new









Here's another one:

http://coffeesnobs.com.au/home-roasting-tips-tricks-ideas/48343-gene-automation-mod-lcd-version.html

I just wanted to find out how to do this and I think I pretty well know how to now. But I'm not in any rush to do it: I've only had the Gene for a couple of months and I want to get to know it well as it is before carving it up. I'm quite impressed with the Gene's roast quality, I have to say, and I doubt that this sort of mod would make things fundamentally better. Perhaps it would make it easier to repeat roasts more consistently ... but then again, part of the charm of roasting at home is the (somewhat unpredictable) variations in the roasts.

So at the end of the day I think I will do the mod, but more for fun than anything else. But I would be more than happy to share everything that I do, if there is any interest. I will do up proper printed cuircuit boards and I can always get a few extra ones done for anyone who would like one.

Cheers

Robert


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## Rob1

mattpitts74 said:


> I've recently got a Gene Cafe and roasted a couple of batches so far. But I imagine in the long term I will end up doing the dimmer mod. But I see that you guys I have evolved it into something a bit more techie.
> 
> I'm wondering if you have had enough time roasting with these mods to know if they are more worth while than the original dimmer mod?
> 
> I'm guessing that having the numbers could be more helpful for making things more repeatable?
> 
> Would you recommend the original mod or your versions with the voltage regulator and screens? Do you think this mod makes enough of a difference to make it worth while?
> 
> Did you end up using this parts list and wiring?


The dimmer mod is 100% worth doing by itself.

The bean mass probe helps repeat roasts and hit your desired finish temperature. Without the probe it can be easy to finish 5c higher or lower than intended and maintaining logs gets tiresome (logging every 30 seconds the power and temp so you can repeat the roast and alter it to make up for finishing darker/lighter than you'd like). With the probe it's all recorded for you, you just need to work to a profile and record any unusual changes you make to the power in response to what's happening with the beans. The way I roast hasn't changed since fitting the probe with the exception of what I do when I hit first crack and how I finish the roast. Colour is an excellent indicator of temperature and it's only as the roast progresses past first crack that the colour changes become more subtle (when viewed in a rotating drum through glass that has baked on coffee oils on it).

Also the original mod requires the use of a power monitor, just so you know. The latest versions with screens and meters built into the box is just another way of providing the same information.


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## mattpitts74

Rob1 said:


> The dimmer mod is 100% worth doing by itself.
> 
> The bean mass probe helps repeat roasts and hit your desired finish temperature. Without the probe it can be easy to finish 5c higher or lower than intended and maintaining logs gets tiresome (logging every 30 seconds the power and temp so you can repeat the roast and alter it to make up for finishing darker/lighter than you'd like). With the probe it's all recorded for you, you just need to work to a profile and record any unusual changes you make to the power in response to what's happening with the beans. The way I roast hasn't changed since fitting the probe with the exception of what I do when I hit first crack and how I finish the roast. Colour is an excellent indicator of temperature and it's only as the roast progresses past first crack that the colour changes become more subtle (when viewed in a rotating drum through glass that has baked on coffee oils on it).
> 
> Also the original mod requires the use of a power monitor, just so you know. The latest versions with screens and meters built into the box is just another way of providing the same information.


Thanks Rob for info, do you have a complete parts list anywhere for your dimmer mod and the bean mass probe?


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## Rob1

The link's in my signature "Bean Mass Probe". I believe the Bluefruit EZ link is currently undergoing revision, the new one might be available but then again it might not and connections might be different. The battery will also be a PITA to get.


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## RA5040

I'm making some progress. Here is a first crack at the controller app (written in Java ... so it will run on Windows, Linux or Mac, but not on tablets or phones):

http://www.irelandupclose.com/customer/coffeeforums/roasterLogExample1.jpg

The data is just made up as I don't yet have the Gene hardware available (parts on order though).

What I've implemented so far is as follows:

- Connection drop down list and button at the top

- Set target temperature (same as Gene)

- Set end time (same as Gene)

- Load Profile: this allows the user to load a previous run and either have it just for reference, or instruct the roaster to try to match it (Set Profile)

- Override the set profile by clicking on Set Temp.

- Restart the set profile by clicking on Set Profile

- Start/Cool/Emergency Stop

- Emergency Stop can be restarted (to allow for dumping of beans and either doing a new roast or running the Cool cycle)

- Click on 1C Start and 1C End to set markers for start and end of 1st crack (I'll add 2C Start)

- Save current run as a profile that can be run, and also save chart as a jpg.

- Errors from the Gene will be reported (and appropriate action taken).

As you can see, I'm intending to monitor input air temperature, exhaust air temperature (from current Gene probes) and bean mass temperature (probe in the drum). As it's possible to determine the drum position from the Gene hall-effect sensor, measuring BMT should be fairly good.

I will most likely use an ESP32 for the main controller as it's much faster than the Atmega328. I intend to phase control the heater.

... still, all some months away yet!

Cheers

Robert


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## RA5040

This is more like the final version of the Gene Controller/Logger:

http://www.irelandupclose.com/customer/coffeeforums/roasterLogExample2.jpg

I've added 2nd Crack start and end, and also the instant temperature readings (at the bottom of the chart). I've also moved the control panel to the right (as I'm right-handed).

Robert


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## RA5040

If you would be interested in checking out the current version of Gene controller/logger software, you can get it here:

http://www.irelandupclose.com/customer/coffeeforums/Gene.zip

Unpack the file. Then to run it open a command window in Windows, or terminal window in OSX/Linux. Run the program by typing in:

java -jar Gene.jar

You don't need any hardware ... the software currently simulates the hardware.

You must first select a port at the top and click on Connect. Any com port will do.

You can then click on Set Temp (to send temperature value to simulated Gene ... value will be shown in terminal window).

Then click on Start to run a simulated roast (the data is in data.txt)

Either during or before you click on Start you can Load Profile. Navigate to Profile.txt. This will show the profile (from a previous roast normally). Then if you want to you can click on Set Profile and this will start to send temperature settings to the Gene (terminal window for now).

If you want to override the profile, click on Set Temp. and this will send the temperature setting to the Gene. You can restart the profile by clicking on Set Profile again.

To end the roast click on Emergency Stop.

Here's a quick video showing the program running: http://www.irelandupclose.com/customer/coffeeforums/Gene.mp4

Have a look at the folder: you will see that the chart and profile for this roast have been saved with a date/time names.


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## RA5040

If you would be interested in checking out the current version of Gene controller/logger software, you can get it here:

http://www.irelandupclose.com/customer/coffeeforums/Gene.zip

Unpack the file. Then to run it open a command window in Windows, or terminal window in OSX/Linux. Run the program by typing in:

java -jar Gene.jar

You don't need any hardware ... the software currently simulates the hardware.

You must first select a port at the top and click on Connect. Any com port will do.

You can then click on Set Temp (to send temperature value to simulated Gene ... value will be shown in terminal window).

Then click on Start to run a simulated roast (the data is in data.txt)

Either during or before you click on Start you can Load Profile. Navigate to Profile.txt. This will show the profile (from a previous roast normally). Then if you want to you can click on Set Profile and this will start to send temperature settings to the Gene (terminal window for now).

If you want to override the profile, click on Set Temp. and this will send the temperature setting to the Gene. You can restart the profile by clicking on Set Profile again.

To end the roast click on Emergency Stop.

Here's a quick video showing the program running: http://www.irelandupclose.com/customer/coffeeforums/Gene.mp4

Have a look at the folder: you will see that the chart and profile for this roast have been saved with a date/time names.


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