Hello All. I'm creating a PCB with a Nano embedded as the controller and a PIR sensor and an NRF24L01 being the other active components. Also off this board will be a mosfet driven, 200ma led array. The board will be powered by a regulated 5VDC, 2A switching wall wart power supply. I'm seeking suggestions as to what capacitor(s) it might be prudent to add to the PCB and where they should be placed. Thanks - Scotty
0.1uf decoupling caps from Vcc to ground as close to the processor as possible. (Edit: those are probably already on the Nano board) 10 to 47uf across the 3.3V (to ground) supply to the NRF24 to help keep radio supply voltage stable.