Thursday, August 12, 2021

Espresso machine software testing

 Testing a mostly-functional espresso machine gui.  Somewhat Decent inspired.  While I don't have an interface for creating espresso profiles from within the gui, I can write arbitrary espresso profiles/state machines in python which is pretty powerful.  Testing with the Puck Simulator.


The profile in the video does the following:
  • Cycle water through the tank at 2 mL/s until the water and the group head get up to temperature (I cheated this in the video and turned off heater power)
  • Flow water through the group head to the drip tray at 2 mL/s for 2 seconds to purge the air from the group.
  • Block off the drip tray, flow to the group at 2 mL/s until the pressure reaches 6 bars.
  • Run at a flat 6 bars until the shot weight (estimated from the pump speed/pressure/flow curve since I don't have a built-in scale yet) reaches 32 grams.
  • Open the valve between the drip tray and group head to rapidly purge pressure (so it doesn't keep dripping)
  • Reset to the beginning and wait for input.

2 comments:

  1. What are your next steps for this? :)

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    1. There's a whole lot of packaging and integration to do. Basically everything is going to get remade. I want to get the software fast enough to run on a raspberry pi or similar SBC that could be intergrated into a machine. And in the mean time, actually make espresso with it :)

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