Why are LED's receiving different voltages connected to Arduino I have four LED's all connected the exact same way to four pins via four 150OHM resistors. (ignore the sensors, they are doing nothing currently) The code is very simple in the loop:

  digitalWrite(blue1, HIGH);
  digitalWrite(green1, HIGH);

  digitalWrite(blue2, HIGH);
  digitalWrite(green2, HIGH);


Here's a photo of the setup, notice how the LED's all light up differently. They are receiving the following voltages from left to right (2.48, 1.72, 3.02, 2.15):



Why is this happening and how do I get them all to light up the same?
After trying another Arduino I realized the problem. I did not use pinMode in the setup for all of the pins. Darn.