FEZ Domino - different voltage for digital outputs


I am user of FEZ Domino board. I was doing some little project where i used eight digital outputs and leds (leds and appropriate resistors were all the same). I have found that for outputs 2 and 3 voltage seems to be lower than for the rest of the pins (leds lit weaker). Could anyone explain reason for that? I found that pins 2 and 3 are connected with I2C SDA and SCL. Is there any connection between these facts?

Thanks in advance,

Welcome to the forum.


The I2C pins include pull up resistors on the circuit board, which create a voltage divider when used with a LED and resistor. That is why you are getting lower voltages. Try different pins.

Thanks for reply. Everything is clear now.