I built a solar powered one, that worked fine in the UK (even during winter) for a few months until a hardware failure occurred (I think condensation in the enc

I built a solar powered one, that worked fine in the UK (even during winter) for a few months until a hardware failure occurred (I think condensation in the enclosure). As others said you need to find a good breakout board. I had good luck with a ESP8266-12 (http://blog.hekkers.net/wp-content/uploads/2015/03/ESP-8266-12.jpg http://blog.hekkers.net/wp-content/uploads/2015/03/ESP-8266-...) which consumes µAs in deep sleep mode. As others said, if you are really serious about this you would be much better to go with a ATTiny or similar, but then you don't get radio out of the box, so need to work with 433mhz modules or similar.