Arduino Coffee Machine’s documentation


This project is a work in progress, I will update the documentation while I progress with the work and things might change along the road


This project is a modification for Gaggia coffee machines replacing the existing thermostats with a PID controller powered by Arduino. This modification could be applied to other machines too, but in this document I will describe how I modified a Gaggia Paros. The Gaggia Paros is almost identical in its parts to a Gaggia Classic and it comes combined with a coffee grinder.

To add a PID controller to the coffee machine we’ll need to replace the existing thermostats that control the heater. There are 2 thermostats to allow the operation of the machine heating water to brew temperature and also steam temperature. Unfortunately these thermostats do not allow a fine control of the water temperature, being a simple on/off switch without any logic behind. The result is that they don’t keep the water/steam temperature stable enough to allow consistency of the brewed coffee.