I am testing different low power libraries with the Nano 33 IOT. I am powering it via battery into VIN. I have a very simple sketch (below) which goes into LowPower.sleep (using ArduinoLowPower) for 5 sec. and then delay for 5 second. Whats interesting is if I run the sketch with nothing else plugged into the board then in low power state its consuming ~19ma and in delay its consuming ~24ma. However, if I plug into the usb interface on the board and NOTHING on the other side (ie. its not plugged into the computer), then in low power state it consumes ~5ma and in delay it consumes ~17ma.
Why is having a usb cable into the board, with nothing plugged in on the other side, have such an effect on the power consumption? Is there a way that I can achieve the same without having a cable hooked into the USB port?
#include "ArduinoLowPower.h"
void setup() {
}
void loop() {
// put your main code here, to run repeatedly:
LowPower.sleep(5000);
delay(5000);
}