Gaggia PID for RP2040

Firmware

Add steady boiler control and an OLED shot timer

This DIY controller adds PID boiler-temperature control and a small OLED showing temperature, status and shot time. It uses a Raspberry Pi Pico or RP2040-Zero, a Pt 100 sensor with MAX31865 interface and a solid-state relay.

The documented build is an EU Classic Pro; match its wiring before choosing this route. It requires mains-wiring and soldering skills, a source build and local edits to the author’s SDK and flashing paths. The pump-stop relay was not installed in the author’s machine, so the verified shot-timer feature measures time rather than stopping a shot.