Modifying the Coffee Machine

First the base plate was removed with a special screwdriver and a moderate quantum of force.

Then a 5V relais was put in series with the power switch. If the relais was unpowered, the the relais was closed. This enables the coffe machine to be used in normal mode in case the electronics are unavailable.

The coffee pot had to be modified so the the coffee level can be determined. We took some thick aluminium foil, cut out two pieces and glued them on the side of the machine unsing a two component and ill smelling epoxy glue.

A first check showed that the capacity varied as a function of the water level in the pot.

Then the electronics were build. The detailed construction plan is not available here yet.

For the parallel port these pins were used:

• Pin 1: OUTPUT Coffee machine power ON/OFF
• Pin 2-9: INPUT 8-bit pot level
• Pin 11: INPUT Check status pin 1
• Pin 19: GND

The electronics were assembled, interfacing the coffee machine with the parallel port of the Linux PC.