In this repo you find the source code for my Best Improvement v1 board, a better board with better firmware to control the Best BST-863 hot air station. This is for v1 only (STM32 microcontroller), if you are looking for v1.5 (RP2040) click here.
You can buy the board on my tindie store.
If there is a compiling error you might need to install SAMD M0+ boards through the boards manager on Arduino IDE