2022-03-07: Espresso Machine Modifications done

Meeting Information

Participants

• Stefan Lüthi (maintainer)
• Roger Weber (advisor)

Agenda

1. Milestone: Espresso Machine Modifications done

Meeting

1. Milestone: Espresso Machine Modifications done

   1. Evaluation of milestone objectives:

      1. These modification were done to the espresso machine:

         • Add thermowell to measure water temperature inside the boiler.
         • Add 0.5mm thermocouple to measure water temperature inside the group head.
         • Add a water pressure sensor.
         • Add a flow meter before the water pump.
         • Mount power control PCB and solid state relay to control pump, valve and boiler.
         • Clean and descale every machine part.
         • Order heat resistant (>120°C) strand wires to replace the cabling.

      2. The modification was on tight schedule because the PCB production took longer than expected due to queries. 42h were planned for the modification, it took 46h and will need an additional 8h to finish.

      3. The milestone was missed, which has the following consequences:

         • The additional time for the modification was used from the kernel documentation budget.
           • To provide enough time to finish the documentation the final application milestone will be moved from week 26 to week 24.
           • The demo application will lack low priority features such as pressure control.
         • Additional 8h are needed to complete the modification.

   2. Next steps:

      1. Mount processing unit and 3D printed case to the machine.
      2. Glue a RTD sensor to outside of the boiler and group head.
      3. Replace all cables with new wiring.
      4. Reassemble the machine.

Next Meeting

according to sprint cycle