- Running the ATmega328P at 8Mhz drops the consumption drastically. That way you can have U3 Module to run on a battery for a long time.
The onboard battery charger makes sure you can charge the battery from a solar panel, or any other source without having to use an external LIPO charger.
By placing the MCU on a sleep mode, you can drop the consumption to less then 200µA!
Just like the U2 Module, the NRF24l01 can be used, to transmit your data from and to another Arduino™.
Important. U3 is a 3.3V module! Do not connect with 5V.