MicroPython and a Raspberry Pi Pico PID Controller Help VEEB Projects Build a Better Burger
Maker collective VEEB Projects has released its latest creation: a smart-looking PID controller, with a small OLED display and rotary encoder for setting a target, powered by a Raspberry Pi Pico microcontroller board.
"A proportional integral derivative (PID) controller that will be used to run a home-made precision heater," the collective writes in the notes for its release, dubbed the Heat-o-Matic. "PID is a fancy way of saying that the code plays a game of 'Warmer', 'Colder' to get something to a particular value (in our example, a particular temperature)."
"The internet is littered with examples of these things, so it is primarily a didactic exercise that will use a few bits of code we've previously developed, and hopefully it will make us a little smarter along the way."
The MicroPython-based project is built around the Raspberry Pi Pico — and should, in theory, be compatible with other RP2040-based boards too. There's a compact OLED display panel and a rotary encoder to form the user interface, a temperature sensor as an input, and a relay connected to a plug socket as an output.
"Plug it in, pop the temperature probe into the medium you are going to heat, plug the heat-providing device into the plug socket, pick a setpoint using the dial. That's it," the collective writes. "Fun fact: sous vide means 'under vacuum', so even though it's how the method is often referred.... it doesn't quite apply here."
The source code for the project is available on the VEEB Projects GitHub repository, under the reciprocal GNU General Public License 3; a wiring diagram is not yet available, but is on the collective's to-do list.