2012-10-19 Rpi + MD03, separate power and control sources

Bring-up test of the Difftrike's new electronics (3rd generation): Raspberry Pi main controller running Debian GNU/Linux and a Python script, and an MD03 20 Amp 24 Volt power bridge from robot-electronics.co.uk.
So far, so good, the I2C bus is fit as a fiddle, but this is with a stabilized 5V power source feeding the electronics. We shall see how it all fares when all the power lines are connected to the main battery...