4) Wire up the Circuit
You will build this sensor circuit using the XBee Development Board. It’s a good idea to unplug the USB power before working with the electronics.
- Plug in the temp sensor into three separate rows on the breadboard as shown. With the flat side facing you, the pins are numbered 1 to 3 from left to right.
- Connect a red jumper wire from a socket in the same row as pin 1 of the TMP36 to 3.3 volts power.
- Connect a black jumper wire so that pin 3 of the TMP36 is connected to GND (ground).
- Plug in the four resistors to separate rows of the breadboard as shown. They will form a chain with the each resistor connecting to one end of each resistor on either side and scale the input down from 3.3 volt input to the 1 volt maximum of the XBee Zigbee’s ADC.
- Connect a blue (or any other color) jumper wire so that the middle pin (2) of the TMP36 is connected to the open end of the first resistor.
- Connect one end of a yellow (or any other color) jumper wire to the row where the first and second resistors meet. Connect the other end of this wire to to the XBee’s AD2 pin.
- Use a black wire to connect the open end of the fourth resistor to GND.
- Set the DIP switch for AD2 on the PCB to OFF to disconnect the soldered-on component.
- Here’s what everything should look like, with the power plugged back in: