Xbee — Making Connections

Xbee radios can be connected in countless ways.  The limits are imagination and only to small degree budget.

This post is an overview of some of the strategies for making electrical connections with equipment in our labs.  The start simple and become more complex.
!!!!REMEMBER XBEES ARE 3.3V DEVICES!!!

Strategy 1: xbee explorer

Available online and in the cabinet.

These are as easy as plugging in the radio and attaching the USB cable.  These boards supply the needed 3.3V automatically.  Look for the thin white outline on the board for orientation of the radio —  the “top” of the radio should face away from the cable connection.

If you solder header pins to the main board it can be attached to a breadboard — and then to your arduino.  As shown it can make direct connections to any software with serial capabilities.

Strategy 2: RS232-USB Breakout Boards

Available online (rs-232, xbee board) and in the cabinet.

This strategy is similar to the xbee explorer board above — but now split into two boards.  The right board carries the radio, the left board handles communication protocols (it can be used with lots of devices other than xbees too!).

Because you have two boards you now need to make power and serial connections — not just snap in the radio.  Grounds (green on left, black on right) for each board must be connected to the ground bus (blue rail on breadboard).  Power (3.3V) for the radio is brought from the RS232 breakout board to the radio via the yellow wire (details below).

Serial connections go from Rx of RS232 to Tx of xbee and vice versa.  The xbee boards label Rx as Din and Tx as Dout.  This is called crossing over (look at ends of blue and white wires above).  it may help to think of connecting ears (Rx) to voice (Tx) when speaking — but, then again maybe it won’t.

POWER — is 3.3V!

You need to be more aware of voltages with this strategy.  The RS232-USB board on the left can supply 5V

and 3.3V.  Power connect should go from the SECOND pin (yellow #2 below) on the RS-232 board to pin one (1) of the xbee breakout board. Pin 1 carries 5V — so you need to double check before connecting the USB cable.

Strategy 3: Use Your Arduino Board

For this strategy you must remove your micro-controller chip — you can then use the Arduino board as if it were an RS232 breakout board.  Removing the chip straight forward (if you don’t have a chip puller, a screwdriver can be used to gently lift it out)– just go slow and be patient.  Remember to note the orientation of your chip — the notch faces the outside of the board.  You will want to re-place the chip in the same orientation.

As in the breakout board strategy (#2) above — you need to make 4 connections: 3.3V, ground (gnd), Rx adn Tx.  In this case the Rx and Tx lines do not cross over (look carefully at the ends of the white and blue wires).

3.3 volt power can be obtained from the board (detail below).   The radio is wired as above.