Here is a great Raspberry Pi based Reflow oven controller from “apollo-ng” on GitHub. You can edit your temperature curve on your browser and Rasberry Pi controls the solid state relays and fan.
Turns a Raspberry Pi into a cheap, universal & web-enabled Reflow Oven Controller. Of course, since it is basically just a robot sensing temperature and controlling environmental agitators (heating/cooling) you can use it as inspiration / basis when you’re in need of a PID based temperature controller for your project. Don’t forget to share and drop a link, when you do.
How to Control a Reflow Oven with Raspberry Pi – [Link]