Based on all the input, I am now tempted to go for one Shelly Uni for each garage door opener. With a din-rail holder, it looks like a decent solution: very simple wiring, similar web interface as my other Shellies, supports MQTT like my other Shellies.
When I look at the wiring diagram of Shelly Uni, it looks to me like my garage door opener sensors behave like in the part highlighted with the red arrow:
That would mean that the wiring between my garage door opener and a Shelly Uno could be very simple:
| Description | Garage door opener | Shelly Uno |
|---|---|---|
| GND | pin 1 | pin 2 |
| VCC (24 Volt DC) | pin 3 | pin 1 |
| Sensor door open | pin 5 | pin 7 |
| Sensor door closed | pin 6 | pin 8 |
Unless somebody sees a blocking error (through his electronic glasses...), I am going to order a couple of Uno's...
