Ok, finally it's solved. I installed everything from scratch. Then installed your sandeep lib from your github. And finally added the LEDs and Buttons to the variants.h. That compiled successfully. And my problem was that the sensor is sleeping and I couldn'T get a heartbeat answered.
So everything is clear and now testing...
Hi @chey, no, with the pro minis and MySensors lib I couldn't get less.
Didn't measure with yet another multimeter though...
My battery sensors are working now for about a year and the battery levels are between 65% and 70%.
The sensor furthest from the gateway is at 65% and the 3 others at 70%.
Not bad I think.
https://forum.mysensors.org/topic/11499/checking-mechanical-locked-doors-by-a-battery-based-windows-door-sensor-node
For those of you who want an extremely simple build, I've reduced it to just 5 parts:
one 1-megaohm resistor (0805 SMD)
one Arduino Pro Mini
one Ra-01 LoRa module
Male header pins
Battery clips
See photos.
