We set up our audrino and breadboard and LEDs and created a switch made of two exposed wires, but our yellow LED was not working.
After checking the placement of everything, we were pretty sure all the wires and resistors were inserted correctly so we took our voltage reader to test where the problem was. Why were we not getting electricity from the audrino? Was there a problem with the breadboard? Was the yellow LED just blown? The voltage meter told us that we were getting 5v of electricity on the beginning of the circuit.
Then we moved the power and the ground from the bottom rail of the breadboard to the top rail, inserted them in row 1 and row 2. The yellow LED was still not lighting up.
So we tested if there was voltage at the beginning of the yellow LED's resistor and there was. We pulled out the resistor and closed the switch for a short second (to test it) and the yellow LED worked. So we knew we had a resistor problem and inserted a different one (a 470 ohm) and it worked! We also moved the switch power end to rail 5 and the ground end was vertical in row 6.
