4) Wire up the Circuit
You will build this sensor circuit using the XBee Development Board.
- Plug the 270 ohm resistor into the breadboard as shown. It will limit the current flowing to the LED.
- Connect one end of a yellow (or any other color) jumper wire to the same breadboard row as one end of this resistor. Connect the other end of this wire to the XBee’s DIO4 pin.
- Plug in the LED so that its long leg (+) connects to the same junction row as the open leg of the resistor. The shorter leg (-) goes into another unused row. (Note: an LED has polarity, meaning that its orientation matters! If you put it into this circuit backwards it will not light up.)
- set the DIP switch for DIO4 on the PCB to OFF to disconnect the soldered-on component.
- Here’s what everything should look like: