How I Hack a RC Toy Car to Control It From an Android Phone. Part 1: Toy Car Teardown
Update : We’ve been compiling this series in Chronopad. It is presented in chronological order so that you know the correct sequence of the stories.
I have always wanted to make a toy car that can be controlled from a smartphone. It will look so cool, like those gadgets from the spy movies. Even at that time I already knew that the connection from the smartphone to the toy car should be using Bluetooth, not WIFI or via the Internet (though using any wireless connection will be equally cool). So using the early version of Android + Arduino connection architecture, I began my work to design the toy car.
After a while I realized that if I want to create the toy car from scratch, there will be a lot of work and the easiest way to create the custom parts are by using 3d printer, an equipment that I don’t currently have. So procrastination took over, and this project does not go further from a CAD design and an Arduino schematics.
But then a few weeks ago, I have this idea, why don’t I hack an existing RC toy car, tear down the transmitter a.k.a the controller and connect it to an Arduino board. Then I connect the Arduino board to Android phone using HC05 via Bluetooth connection. I don’t need to tear down the toy car itself, although I might do it in the future if I decide to convert the car into some kind of mobility platform (I already imagine it as a mobile sensor platform, but that’s a story for another time).
The rough diagram looks like the picture below.
It should be simple enough, does not cost me a fortune, and can be completed in a short time. So I decided to pursue this project.
The RC Toy Car
I went to a local eCommerce website and look for the cheapest RC toy car I can find. The search only took a few minutes, and I got on my hand an RC toy car for around $10.
I already have an Arduino board and the necessary components so I don’t need to purchase anything else.
The transmitter is an ordinary pistol grip controller with the trigger for forward and reverse movement, and the wheel to turn the car left and right.
It is powered by 2 AAA batteries.
I proceed with tearing down the transmitter so I can trace the circuit wiring and know which part of the circuit should be connected to the Arduino board.
The 4 miniature pushbuttons are activated by either the trigger or the steering wheel. The mechanism is quite simple.
The forward and reversed buttons are pressed by a small arm that is connected to the trigger. And the left and right buttons are clicked by a small arm connected to the steering wheel so either left or right button is clicked when the wheel is turned.
All buttons are connected to a LED that will be switched on whenever a button is pressed. Now I have figured out the transmitter’s circuit design and the connection between the electronic components. Next I have to figure out how to connect the transmitter circuit to the Arduino board.
