Reflow Oven Controller
A prototype reflow oven controller. A Teensy++ 2.0 provides an 8-bit AVR microcontroller to run the control algorithm. Two MAX6675 ICs provide two channels of thermocouple sensor readings. Two solid-state relays allow independent control of two high-power AC loads (the top and bottom heating elements of my toaster oven, in this case).
The whole PID control algorithm and temperature profile reside in and execute on the AVR (all implemented with fixed-point integer math). Still, I've also written a Python/QT GUI program that talks to the AVR (through a USB virtual serial port) and allows for plotting the reflow profile/sensor readings/SSR commands/etc. in real-time as the reflow operation runs.