Car Analysis

The simple RC car usually contains one brushed motor for rear wheels driving and one bushed motor for its steering. The driving is limited to the full speed backward and full speed forward. The steering is limited as well, the motor can turn wheels to the left or to the right at the maximum angle, and there are no intermediate driving positions besides centre value. Also then the wheels are turned to some side the motor is stalled, as it keeps turning to the desired position but some gears prevent it from going in that direction – thus motor stalls and gets very warm.

In other cars, steering is controlled using magnets – each front wheel is connected to the magnet which attracts the centre knob of the steering mechanism then the voltage is applied to the steering magnet, so if we want to make a left turn, we apply voltage to the left magnet, and if we want to make a right turn, we apply voltage to the right magnet.

Some cars also has built-in lights, what’s strange that those lights are not controllable, but just light up than you go forward or backwards.

And finally the car contains some control board that accepts commands from the remote control pad and drives motors, lights, and steering magnets. This board consists of a receiver module and a h-bridge for driving motors (usually just a couple of transistors or FETs are used to make a h-bridge instead of a h-bridge chip) and some transistors for controlling steering magnets or lights.

So let’s build our own controlling board with additional features:

• Controllable by a smartphone instead of a remote controller.
• Several cars can be controlled by the same smartphone (not at once).
• Adjustable driving speed.
• Individually controllable lights (if available).
• Adjustable steering (if possible depending on steering mechanism setup).