This is an old revision of the document!
Wire up the receiver
The transmitter XBee connects directly to the FTDI cable/computer and the receiver is wired to the target Arduino. Here I use a half-sized breadboard and rubber band since not much space is necessary. Solder a wire from pin D3 on the receiver XBee adapter, so that you can plug it into the breadboard. This is the mirrored reset line from the transmitter Xbee.
Xbee's are pretty weak and dont have the oomph to reset an Arduino on their own, so we need to wire it up to a transistor which will do the heavy lifting of pulling the reset line down. Pretty much any small NPN transistor will work just fine here. Put a 0.01uF to 0.1uF capacitor in series with the wire from the XBee, and connect the other side to the NPN transistor base. The emitter of the transistor connects to ground. Put a resistor around 10K between the base and emitter. This will pull down the base to keep the Arduino from resetting accidentally.