I'm using the following simple code snippet to write to the D3-pin of my Arduino Nano RP2040 connect.
for(int i = 0; i <= 0xff; i++) {
analogWrite(3,i);
delay(10);
}
USB is connected and I have a voltmeter connected between the D3- and the 3V3-pin.
Result: The voltage increments over time, is then reset and starts incrementing again.
Everything as expected so far.
So I disconnect USB and connect the Arduino VIN-pin and the two GND-pins to a 9V power supply.
The builtin LED on the board turns on, but when I connect the voltmeter to D3 and 3V3 again, I get a constant voltage of 3.3 volts.
Why?
while (!Serial);
insetup()
?