15 A simple circuit 2

Find two short wires in the box of electronic components. Insert the end of one wire into the ground rail of the breadboard (the row of holes marked with the light blue line on the breadboard). Use the second wire to connect the resistor (column \(29\)) to the ground rail of the breadboard as shown in the figure below:

All of holes of the ground rail are electrically connected together; any connectors plugged into the ground rail will be electrically connected.

To complete the circuit we need to connect the the resistor and LED to a power supply. We will use the Phidget as a power supply (actually, we will use the USB port of the computer as a power supply; the Phidget simply makes the power provided by the USB port available to other devices).