Build a datalogger for your wireless sensor network

Step 6 Wire up the Arduino MEGA, Logger Shield and TelosB

Add a socket to the 3V pin on the Logger Shield, and a socket to a ground pin. Connect jumpers from here to the 3V and ground pins on the TelosB. The Logger Shield is a good place to get power out to the TelosB because it has a nice onboard 3V regulator.Plug in the TX wire from the TelosB to the Serial1 RX socket on the Mega. This socket is not connected to the DataLogger shield, it's one of the many extra sockets the Mega has that the regular Arduino doesn't.
Now to communicate with the real-time clock on the Logger, you have to use the Mega's hardware SDA and SCL lines but these aren't connected to the right pins on the Logger shield. You have to add a jumper from "SDA" on the Logger Shield to SDA on the Mega. Do the same thing to connect the MEGA SCL and Logger SCL pin. It's best to install a 2 pin socket on the Logger Shield rather than soldering the jumper wire directly to the logger. Note that you can't use Mega's pins 4 and 5 for other purposes, because they're already connected to SDA and SCL through the Logger Shield and any additional signals on these pins will mess up communication with the real-time clock.Now there should be 5 wires going between the TelosB, LoggerShield and Arduino MEGA:3V, 5V, tx/rx, SDA and SCL. That small orange jumper wire is there to connect up the green LED on the datalogger shield, but it's optional and probably would be smarter not to use it.