What kind of wireless is recommended ?
I have some NRF24L01+ modules, i have ESP8266 but none RFM69, what kind of module is recommended for battery operation ? My guess is either NRF24L01+ or RFM69 since ESP8266 is not suited for battery operation in the long run. I need to make few sensors which are outside of the house so it would be nice for battery operation.
@donnib A 3.3V Arduino Pro Mini is recommended for battery powering, see https://www.mysensors.org/build/battery for details.
For a comparison between rfm69 and nrf24l01+, see https://forum.mysensors.org/topic/3993/nordic-or-hoperf-radio
nrf and rfm use roughly the same amount of power, so battery-wise there is no big difference.