Best hardware for counting coffee cups

Hellow fellow Arduino members,

Currently I'm investigating the setup of a table with 3 coffee machines. I want to count the number of times the user requests a cup of coffee, and was thinking of doing this by placing a hall effect sensor over the cable to measure changes in the magnetic field around it. This would be a regular 220 V cable (Europe) that goes into a power socket.

This sensor would be connected to an Arduino with integrated WiFi. Each time the power peaks, I'd a +1 to the database.

In my head this setup would work, be it not that accurate as one of the machines sometimes rinse and clean itself automatically. However, it's more of a gimmick project, so not real accurate data is needed.

But maybe there's better advice on thinking about hardware for this. Looking forward to hear your ideas!

/edit PS: all ideas welcome, still need to buy everything

The "rinse/ clean" cycle should be distinguished by a different power and timing profile.

I suspect the hall effect sensing will be too troublesome as it is very dependent on the positioning of the sensor - only really practical if you can separate one of the power wires to be monitored.

You can buy power monitors which plug into the power point, and which measure total power used between resets. Concealing these in a box and reading them daily - or whatever - may be much more practical.

Cant you just use an IR trip wire ? or a IR distance meter, which you adjust to your needs, if positioned correctly it will not drip when it cleans it self.

Not sure about the IR DC!

Thanks, Paul B. It might be a better option indeed.