alnath:
each Led is connected to an arduino output, which provides 5V when HIGH. Without the resistor, the current through the Led and the output would be too high. The Led and/or the output would fry
I think I get it now! Thank you so much 
alnath:
each Led is connected to an arduino output, which provides 5V when HIGH. Without the resistor, the current through the Led and the output would be too high. The Led and/or the output would fry
I think I get it now! Thank you so much