Hey, I am following this instructable http://www.instructables.com/id/RC-Car-to-Robot/?ALLSTEPS I have everything put together correctly and have a bigger truck than he started out with. The problem I have run into is my ping))) sensor only turns on (led indicator flashes) when the rear motors are switching from backwards to forwards. I would assume this is because the motors are taking up the voltage needed by the ping))) sensor. I have two nine volt batteries powering my project ( one 9-volt connected to arduino uno and one 9-volt connected to the motor shield). If the problem is what I suspect, is there any way to limit how much of the power input that the motors use? Thanks so much!
[EDIT] When plugging in the 9v to either the Uno or the Motor Shield AND plugging in a usb connected to the computer into the Uno, I get the result I want.[EDIT]