[Nicholas] wanted to add some flair to his RC car. In addition to the headlights that you see above, there’s brake lights, and a horn that plays “Dixie” like the General Lee in the Dukes of Hazard. All of this is triggered by the wireless controller, but he figured out a way to monitor the servo signals in order to add the additional features.
The hack is driven by a Propeller chip. [Nicholas] patches into the servo lines by adding a servo-in and servo-out header to his prototyping shield. With that in place he’s able to tap into the voltage and ground pins to power the microcontroller. By attaching a 4k7 resistor to the control line, he can listen in on the servo signals using the Propeller.
This RC car has a throttle servo. So when the throttle is opened all the way up the Propeller chip flashes some white LEDs in the headlights, and uses an LM386 audio amplifier to play a tune. When the throttle is pulled all the way back the brake lights are activated. Don’t miss the test footage of this which is embedded after the break.