TC4+ boards and Arduino controlled roaster by Matthias Gerstgrasser
|illustration by Matthias Gerstgrasser|
On the mailing list for Artisan users, Matthias Gerstgrasser posted a report about his coffee roaster project, with a link to a beautifully illustrated, complete step by step guide of his work on Instructables:
A while ago I posted a few messages on here regarding automation for my hot-air popcorn roaster, and was asked if I could share a writeup of what I had been doing with my setup. I know it’s been a long time, but I haven’t forgotten, just got a little sidetracked (more on that below).
I have finally found time to do this over the last few weeks though, and compiled a step-by-step guide of how I modified my popcorn machine. This is now available on Instructables: https://www.instructables.com/id/Arduino-controlled-DIY-Coffee-Roaster/
Do let me know if there’s anything missing or anything that could be improved. I intend to keep updating the guide as I find ways to improve it or as new developments occur. I am also discussing both DC and AC fan popcorn machines in the guide, as those seem to be the two main varieties out there, and the difference seems to cause a lot of confusion. Focus is on the hardware modifications of the popcorn machine for now, but if I find time I will try to write more on the software side as well, though I think there’s already good documentation on that out there anyway.
Beyond my own roaster, I ended up getting a little more involved in home roasting than I anticipated when I emailed this mailing list last. This is because of two things: One, I wanted a few additions to the TC4 board I was using at the time (such as a DC fan driver), and I was curious about PCB design, so I designed my own TC4-compatible board for my roaster. Two, Jim, who made the original TC4 boards, retired around that same time, and there were for a while no more TC4 boards available to buy anymore. So, I made my own version available, first through the homeroasters.org forum, and nowadays also through Tindie and my own website.
It’s called the TC4+, and it’s essentially a TC4 with a few improvements and additions: Improved connectors, a DC fan motor driver, voltage regulator to power the board, and a header for an optional Bluetooth or Wifi module. For DC fan roasters this makes the setup a lot simpler than with the old TC4, and even for AC fans the Bluetooth module and changed connectors can be quite useful. It’s fully compatible with the old TC4, and uses the same aArtisan or aArtisanQ_PID Arduino sketches. It’s therefore also fully compatible with Artisan, and looks just like a regular TC4 software-wise. I’m hoping that the board will be useful to people, and that the additions will help keep the TC4 platform up-to-date. As of recently, I’m also offering pre-configured Arduino microcontrollers to go with it, in an attempt to offer something comparable to the old TC4C board for those not wanting to deal with flashing the Arduino.
Documentation is also available on that website: https://coffee.gerstgrasser.net/documentation/
There’s also a discussion thread on homeroasters: https://forum.homeroasters.org/forum/viewthread.php?thread_id=5562
I hope this is all useful to people. Any questions or comments do let me know. :)
PS See also: https://www.tindie.com/products/greencardigan/tc4-arduino-shield-v602/