If you want to dive into the muddy, highly caffeinated waters of the espresso world, then you’re probably considering a machine from Gaggia. They have several different models that are pretty affordable — at least by espresso machine standards. But to keep their costs down, Gaggia did have to avoid superfluous features on their less expensive models. Rabbitcreek’s Gaggia Classic, for example, completely lacked any ability to provide status information beyond what can be indicated by a couple of lights. So, Rabbitcreek designed this DIY multifunction display that mounts on top of the Gaggia Classic.
From the factory, this model simply had a light to signal when it reached the ideal temperature of 195 degrees. It takes approximately five minutes to get to that temperature and Rabbitcreek found themselves standing by the machine the whole time, just waiting for the light to come on. They figured that real-time information about the temperature would provide some sense of progress and so they created this display to show that. The display housing attaches to the machine’s body with magnets and this upgrade doesn’t require any permanent modifications to the machine itself, making it completely reversible.
The parts required to construct this display cost around $60 in total. Those include a Seeed Studio XIAO ESP32S3 development board, a Seeed Studio 1.28” round display touchscreen for XIAO boards, a type-K thermocouple, an Adafruit 12C thermocouple amplifier, and a 1000mAh lithium battery. Those components fit inside the attractive 3D-printed enclosure, which has embedded magnets for easy attachment on the Gaggia Classic. The thermocouple needs to sit against the group head in order to work properly, so you may have a thermocouple wire running outside the machine — though you can put it inside, if you’re comfortable taking your Gaggia apart.
Once mounted on the machine with the thermocouple on the group head, the display will show the current temperature. There are several different themes available and many of them have graphical gauges. So, the display can act as a progress bar of sorts. But Rabbitcreek found that they still end up standing by the machine until it heats up, so they also added a digital latte art function. That lets the user draw cute little illustrations, which is perfect practice for the real thing after the machine finishes heating.
Rabbitcreek estimates that the battery should be good for about 30 hours of active use, which should be enough for months of morning pulls between charges.
