Physical Computing at SVA IXD

Wireless Lab - Doorbell

For this lab we were required to work with a partner, in order to “synch” or configure 2 pairs of x-bee radios and create a doorbell.
The first step for accomplishing this was to connect power from the Arduino to the Breadboard. This was done by both me and my partner. Different from the other labs we have done, this one requires power of 3.3Volts (the xbees will not run with 5 Volt power).

The second step is to mate the breakout board with “male” headers, which have to be cut out for them to fit on the breakout board. This step is required because the Xbee has pins spaced 2mm apart, which don´t fit in the breadboard. The female headers have to be soldered after on the opposite side of the board.

The 3rd step in this lab is creating Xbee connections from the breadboard to the Arduino.

After, we had to decide who was going to be the receiver (doorbell) and the sender (button). Wire the input and output for the button and doorbell and Configure the Xbees.

The configuration of this radios was done with the XBeeConfigTerminal program. The program opens an interface that asks you to specify the serial port, then write down a PAN ID, (ours was BEEF) and enter it as: ATID BEEF. After the program retrieves an OK, we could continue with entering the ATMY which is “my address”, in this case we started configuring the sender so it used 0 as an address. Then, select a destination address which will be (1) for the doorbell or second configured Xbee radio. The last step is entering ATWR and pressing send for the system to save the settings. The same thing has to be done with the second Xbee radio, specifiying that “its address” is 1 and the destination for it is 0.

Both of the radios have to be programmed with Arduino, uploading a piece of code for each of them. When the code is uploaded, the Serial Ports for each of the Xbees should show a capital D, and the doorbell should be heard. I struggled a lot for the doorbell to ring, and configured Xbees twice, also changed the Xbees thinking there was something wrong with them, after a couple hours of exploring the possible error that wasn´t allowing the radios to connect, we figured out that the soldering was not done properly.

Feedback Doorbell

To receive a feedback in the first Xbee (button) an LED was added to the circuit, allowing this to work as a feedback for the person who is “ringing the bell”. Another chunk of code was uploaded for both of the Xbee radios for this to work.