Very strange: I've connected a transistor to digital pin 4 on the WP controller to turn on a IR led, and when the pin goes HIGH, the IR led doesn't go on at all.
If I measure the voltage on the led it's only 0.2v.
If I use my seperate Arduino Uno it works good.
What can cause the problem?
I wrote this above the setup code:
int transistor = 4;
This in the setup code:
pinMode(transistor, OUTPUT);
digitalWrite(transistor,HIGH);
delay(8000); // to test that the IR led turns on for 8 seconds
The wiring should be good because it works good with my other Arduino.
edit1: it seems that it also isnt working with my other arduino after a new test. I'll start another topic as this is not really the 'robotics'.
edit2: solved, gnd of the arduino needs to be connected to gnd of the power supply.