Circuit Checklist

Before powering on your circuit, make sure that:

• All grounded components are actually grounded (connected to a ground rail on the breadboard that is connected to the GND pin of the Arduino)

• There is no direct connection (by wire or 0-resistance component, such as an LED) between a voltage supply (Arudino output pin) and ground

• The legs of LEDs, resistors, etc are not both plugged in to the same column

  

• You have double-checked that every connection on the circuit diagram matches every connection on the physical circuit (it may help to draw the circuit diagram on a piece of paper and highlight each connection as you check it)

• … Along with that, you have double-checked that the pins you are plugging wires into match the pin numbers on the diagram

• All polarized components, that have an anode and cathode (like LEDs) are wired in the correct direction. In general, the electricity should flow from the anode to the cathode, meaning that the anode should be connected to a voltage source and the cathode should be connected to ground.

• All components are firmly seated in the breadboard