In 2016 I did a small mod on a Gene CBR-101 coffee roaster, which enabled for a more precise temperature setting as well as better reproducibility of the roasting process. Some parts I liked about it and some parts not (like the detached display). So I built a newer version, which uses a 128x64 px LCD display, which can now show the roast curve similar to e.g. Artisan. I wrote a more detailed description in the attached document. Also a video of the automated roasting process can be found here:

Since the description of the first version was in a German forum, I briefly mentioned some measurements from the first version in the document. If you want to build this mod on your own you find a parts list attached. The complied code can be uploaded using a sketch uploader, which skips the compile step in the Arduino IDE. I added a manual description and a .exe which will upload the code for you on the Arduino Mega 2560. For now I do not plan to publish the source code but am open to suggestions regarding the available functions and options as well as compilations for different Arduinos.

Of course you can use the mod with every roaster that uses a binary (on/off) regulation for the heating element with the PID settings available in the menu. Since the fan and drum settings are in percent, the motor controls can be adapted for different voltages or be not used.

I hope that some people can have fun with this mod and maybe we can exchange roast profiles someday...