Here is a short video of the CopperBot driving around:
The speaker and FPV video camera servos are being exercised by the Raspberry Pi through their range of movement while it's driving under remote control. While this may not appear exciting, two problems had to be solved to get here:
First, the Raspberry Pi would reset whenever the R/C started driving the bot around. This was solved by adding some electrolytic capacitors on the power supply at the Arduino and servo boards.
Next, driving the bot was difficult to control, which turned out to be bad configuration of the Sabretooth controller. Switching the mode to "independent" matched the R/C transmitter programming, and now it's much intuitive to control.
The Raspberry Pi also recorded compass, accelerator and gyro data while moving. Later processing it in a spreadsheet, I was able to derive code that will give it good compass heading data. The sensor suffered from a lot of vibration, however, so the frame needs reinforcing and the data will need smoothing to hopefully mitigate the shaky information.