One of my robotics projects which I have completed is a R/C security robot. I finished this project about a year ago, it took me about a month. I had just started robotics so it is a fairly simple robot.
I ripped off the front of a Power Wheels car and put in the front wheels of another toy car which turned with the help of a motor.
Then I salvaged a small R/C car for the remote control part. I took off the motors and attached relays and diodes in their place. The circuit of relays and diodes worked in such a way with the R/C circuit ,that only one relay per function could be triggered. For example the combinations were (forward, right) or (backward,left) but not (forward,backward.) If anyone would like a schematic of the relays and diodes circuit ,feel free to e-mail me for it.
The relays were then wired to the motors ,which made the drive system digital, the motors were either on or off, no adjustable speed. The R/C circuit and drive system were powered by one battery.
A wireless camera, walkie talkie, and a wireless robotic arm was added to it. I was able to drive the robot downstairs from my room upstairs. I hooked up the walkie talkies to my computer and played C3P0 sounds through it and talked to people downstairs.
That was my first real robot and I learned a lot from it.
Email me for info or photos