I have built a robot using the parts listed at the end of this post.
I have been having trouble with the code and getting the motors and the servos to work with the detector but I now believe that this is due to a lack of power.
I am only using 1 x 9v Non rechargeable battery. I can add another 9v battery or use 4 x AA 1.5v batteries.
The problem I have is how do I only use 1 x on off switch? Could I connect this to a common Gnd?