I did some development but it has been "on ice" for over a year. The idea was to offer something running in the "cloud" for quick testing and sharing sensor readings with friends and family. But (as always) it quickly grow out of proportion (storing historic data, dashboards, mail triggers etc) and I realised other projects does this much better. I.e. a hosted NodeRED would do the trick (e.g. https://fred.sensetecnic.com/).
Another issue would also be how to handle the hosting cost for the service (which would require a few more cpu cycles and storage than the current site).

Not sure what will happen with the code, it was pretty tied to the main site with users etc. Maybe I will pick up the work some rainy day.

Bare copper should reflect light. What about sending off ir light (with some dampening material on opposite the other side). And a shielded ir sensor next to the sender to detect the reflected light?

You could perhaps try with one of these:
https://www.ebay.com/itm/5X-IR-Infrared-Obstacle-Avoidance-Sensor-Module-Detect-Distance-for-Arduino-DIY/142649289652?hash=item21368f6bb4:g:nAQAAOSw-4RaUyOd

5X IR Infrared Obstacle Avoidance Sensor Module Detect Distance for Arduino DIY

$1.83

101 available

You should find the password update here:
https://forum.mysensors.org/user/alephian/edit

.. or use the reset password function if logged out.

@rodaman said in Door, Window and Push-button Sensor:

http://www.mysensors.org/build/binary

I don't get the buttonPin array thing at all?

Why not just:
pinMode(i + FIRST_PIN, INPUT_PULLUP);

@rodaman said in Door, Window and Push-button Sensor:

What is the purpose of the buttonPin-array?

E.g.

pinMode(buttonPin[i + FIRST_PIN], INPUT_PULLUP);

This will fetch a random (probably 0-initialised) value from the array and set pinmode on that value...

I had a good laugh when examining the other board. Is this a normal solution for remote-in?