For a project in progress, I have an Arduino UNO sending a message when a condition occurs, and a Raspberry Pi that listens to it. Both are fitted with NRF24L01+ modules with antennas.
It works perfectly when the Arduino is powered from a wall socket, for instance using a 9V / 1A power supply. But when I try it with a 9V battery (which is supposed to supply 600 mAh), the Raspberry Pi receives only 1/10 of the messages.
Could you tell me:
- Why this happens
- How I can solve this problem (software / wiring / capacitor / ...)
- What would be the best way to power an Arduino whose only job is to detect that a switch closes, and emit a message over the air