Inspired by the many autonomous rovers such as Curiosity and the self-driving Google car, [Rohit] decided to build his own by taking an off-the-shelf remote control car and adding his own electronics. Unfortunately, he couldn’t find the datasheet for the chip used to receive radio signals and drive the motors, so he ended up building his own electronics and putting them in the car.
[Rohit]’s car – the Thunder Rumbler RC Car – is driven by applying power to two motors. This is an easy system to control, as only two channels are needed to make the car go forward, left, right, or backwards. To drive these two motors, [Rohit] found an SN754410 quadruple half-H bridge driver chip lying in his box of assorted electronic components. Thanks to a helpful instructable, this chip was easily controlled with an Arduino.
That left the problem of sending a wireless signal to the Arduino. [Rohit] accomplished this by relying on an Android phone to provide the remote control.
[Rohit] whipped up a small program running on his desktop that allows him to send ‘L’, ‘R’, ‘U’, or ‘D’ to the Android phone to dictate if the car should go left, right, forward, or reverse. The Android phone receives these commands via the Internet and sends an audio signal through the headphone port. This audio signal is connected to two analog pins of the Arduino. With a little bit of software and a bit of reading up on frequency shift keying, [Rohit] was able to make his car move in any direction.
Even though [Rohit] realized his goal of controlling a remote control car on his own terms, the build is far from done. He plans on adding some ultrasonic sensors and using the Android’s camera for object detection.