Figure 1: Xbee module connected to the explorer which is connected to the computer

Proving the connection is made

Two of the Xbee modules are connected to the Xbee shields which are then connected to Arduino controllers. On one of the Arduinos is an LED lamp connected to pins 12 and 13 with the correct bias. Code is sent from the computer using a piece of software called the Arduino coder. I had copied the code taken from a project on the arduino website. This means that when a H is received from the serial connection, the LED lights up. An L received from the serial connection turns the LED off. I had no problem sending the message to the ardiuno using the serial terminal from the computer. I typed the letter ‘H’ from the terminal, and it instantly turned on the light. Typing ‘L’ turned it off.

The serial connecter on the arduino worked and this was with the Xbee shield attached. The next goal was to programme the other Arduino to send the letter H and L over and over again.
One of the sketches for the arduino called ‘Physical Pixel’. According to the notes in the program:
- Physical Pixel
An example of using the Arduino board to receive data from the
computer. In this case, the Arduino boards turns on an LED when
it receives the character 'H', and turns off the LED when it
receives the character 'L'.
The data can be sent from the Arduino serial monitor, or another
program like Processing (see code below), Flash (via a serial-net
proxy), PD, or Max/MSP.
The circuit:
  • LED connected from digital pin 13 to ground


Figure 2 Arduino controller: pin 12 and 13 are connected to the LED showing activity

After the second ardiuino was programmed, the next step was changing the jumper settings on both Xbee shields to Xbee setting so that a connection could be made between the two arduinos.
Because both Xbee modules had been assigned the same PANID but different addresses then both should have been able to connect to one another and the LED would light up and turn off at regular intervals without the use of a computer except for power.