extraction · note · in motion
Gaggiuino — PID and profiling on a Classic Pro
Take the Classic Pro apart, replace its internals with an open-source PID + pressure-profiling controller, put a small computer where the thermostat used to live, close it back up. Started for the value-per-dollar reasons; staying for the repeatability.
Why this and not a Linea Mini
The Classic Pro is the cheapest serious single-boiler chassis on the market. Stock, it's a thermostat-controlled box. The Gaggiuino project — an open-source controller built around an ESP32 — replaces the stock control internals with PID temperature control and pressure profiling, integrated into the original chassis, for the cost of parts and a weekend. The value-per-dollar argument is the entry point; what keeps me here is being able to dial in a shot and pull the same shot the next morning.
Through the screen — three runs
Looking up at the dispersion screen as the shot pulls. Same machine, three different pulls — what dial-in actually looks like under the basket.
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RUN 01 through the screen.
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RUN 02 through the screen.
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RUN 03 through the screen.
What the build is
The standard Gaggiuino loadout, retrofitted into the machine: ESP32 controller in place of the stock control board, a dimmer wired into the pump line, a pressure transducer plumbed into the boiler line, a K-type thermocouple on the boiler, and a small front-panel screen let into the original housing. Nothing bolted on the outside — the whole point is that the machine looks the same and behaves like a different machine.
Some pours.
Ordered by latte-art character, not chronologically. Steamed milk from the Classic Pro's stock wand; the controller is upstream of all of these.
Where it is now
Hardware staged, partially wired. The first profiled extraction is the milestone. Once that's in, the next pass is repeatability — same beans, same profile, three days running, see whether the cup follows.
Next
Finish the dimmer + pressure-transducer wiring; pull the first profiled extraction; A/B against the same beans on the stock control to see how much of the cup actually moves.