Blueberry home solutions smart hub for raspberry pi blueberry txrxtemphum the blueberry wireless temperature and humidity sensor features an on board atmega329p microcontrollermcu giving it all the programmability and convenience of an arduino there is a dedicated showerproof abs case 75 0604 for this board together with a pp3 battery by using the sleep functions of the rfm21b sensor and atmega328p a pp3 battery will allow the board to transmit for up to a year the transmission range