I recently build successfully a mysensor node based on an Arduino Uno, a Robolink IR sensor and a Robolink DHT11 sensor. The last two from an Elektor sensor kit ever bought for my son when he was still interested by electronics .
My controller is Home Assistant, so I did a merge of the given MySensors example sketch and the Home Assistant example sketch together with the DHT11 sketch.
The airco is a Samsung one, so in the sketch you will find these defines uncommented. Replace by your airco manufacturer.
People interested in building one, can find my sketch on https://github.com/ericvb/MySensorsArduinoSketches
@ToniA a big thanks for the work to decode all these IR sequences!
@Yveaux Thanks for your response. I guess that's it. I have to burn a bootloader first :-). I have a USBasp Programmer for that. Can you point me to a wiring diagram that shows how to connect the programmer to the circuit board?