@sundberg84, had to migrate my gateway to Ethernet in the meantime but now I am on the PIR/ battery case. i have my booster to 5V in.. will post the results of it...

Hello, Is there a way to solder a DC-DC booster 3.3V to 5V directly onto the Easy PCB or should it be connected separately to power a PIR for instance? and would that really prevent using 2xAA batteries to power the all thing? have tried to step down the PIR to work at 3.3V but it was not conclusive. Thanks a lot.

@sundberg84 that is exactly what i experienced. thanks for the tip. struggling in fact to have my PIR sensor running on 3.3V. when i connect to the pin on the right of the board (3rd from top).. Arduino IDE serial terminal does not outcome any coherent information.

Thanks Stephen. connected both and i can now see what is going on

Hello, i have built my first sensor based on your PCB. I am of course in learning mode so it refuses to work so far. it is motion detector. I suspect a problem on the radio nrf24 but does not know how to monitor the node with Arduino IDE serial monitor. If i connect the board to the USB the radio is not powered (built the node on battery). and if i connect the battery i have no access to serial monitor. I am afraid to connect both the USB and the batteries and burn the all thing...
so far i know radio receives power/ PIR receives 3.3 Volts (have configured the PIR to 3.3)/ arduino mini pro led comes on with battery connected.
Any advice would be really welcome.