There is thousands of motor driver, do you find an easy way to measure the drive current? That is what this motor shield do. The drive chip is L298N. The following steps is how to control two DC motors and how to measure the drive current. With it, you will make your control system more smart.
Crowduino with micro USB. (it is 100% compatible with Arduino Duemilanuve, it added an XBee Socket)
Battery Holder With Switch - 4 x AA or DC 9v power supply.
There are two ways to power the system. One is powered by 4XAA battery, the other way is powered by DC 9v power supply
Disconnect the USB with Crowduino, then plus motor Shield on Crowduino. Connect with DC 9v power supply or push the switch of the battery holder on.
connect to computer via micro USB.
Open the Serial port, then you can watch the drive current of each DC motor.