RC Car Using Accelerometer
This project is modifying off-the-shelf RC car to be control using 3-axis accelerometer sensor. In other words, I am replacing the joystick or potential-meter with a 3-axis accelerometer to control the car movements. Something like playing labyrinth game using iPhone or android phone, where you tilt your phone to move the ball around the maze. Over here, I forward the RC car by tilting the remote control device in forward direction. By tilting the remote control device in correct angle and the RC car will move in correspond direction.
Since the entire project need to be wireless, I using Texas Instruments MSP430-RF2500 in both RC car movement control and accelerometer remote control.
In remote control device, it basically consist of:
Main board, MSP430-RF2500
Accelerometer, Freescale MMA7260 or any free accelerometer sample from manufacturer
Power source, 3.7v Lipo battery or 2 pcs of AA/AAA battery
As for remote control car, it consist a main board, MSP430-RF2500 and two bi-direction DC motor driver, one for steering wheels and one for rear wheels differential drive. As for power source, I use 7.4v Lipo battery to save some weight and space for remote control car. Actually I could just re-use the 4 pcs of AAA battery which is the default power source for this remote control car.
Rear wheels differential drive here are using open loop control method. The more you tilt the remote control device, the faster it rotate without any feedback from the wheels. Whereas steering wheels are using close loop control method, it use a small potential meter as feedback to control the turning angle.