January 08, 2014

Bluetooth remote control car - 2WD

Introduction

Half year ago I made a remote control car with my roommate. It was made of a non-working RC-car, so now I built it from scratch, only using things which everyone can buy. I want to make it as a tutorial for beginner, so feel free to make it as your first arduino project.

What you need:

  • arduino (if you don't have one, buy an arduino uno from ebay, from dx or from the original seller) - $17 (I've used arduino mega, but uno would do the same)
  • 2WD Robot Raider Car Kits for Arduino from dx - $23
  • bluetooth modul. I've used a JYMCU from ebay - $3.5
  • a H-Bridge to drive the motors. I've used L9110S from ebay - $2
  • battery holder from dx  $2.5
  • breadboard and a couple of wire - $2
Sum: $50
And what you got for this money:

Hardware

First build up the car chassis. I think, it's pretty obvious. It comes with 2 DC motors.

H-Bridge

H-Bridge is responsible for driving the motor back and forth. It's also usefull, because gives us the ability to use different powersource (aka batteries) for the motors and the arduino. It's necessary, because otherwise when the motors start, they take so much power from the arduino than it drops the bluetooth connection. To learn more about H-Bridge, see Wikipedia.
Wiring it: it's pretty simple. Just connect one motor to motor A and the other to motor B. On the other side of the IC there are 6 connectors for the power and control. Connect GND and VCC with a breadboard to the battery for the motor, and the other 4 to the arduino pins 8-11. Like this:

Bluetooth modul

Connect the BT modul to pin 0 and 1 so, that BT's RX pin is connected to arduino TX pin (pin 1) and BT's TX to arduino's RX (pin 0). But be careful! If you connect the arduino TX and RX pin it won't get any further data from the USB cable, so connect those pins only after upload your code! 
Also connect VCC to 3.3V and GND to GND on arduino. It should work with 5V too.

Now add power source for the arduino and put on the cover

Arduino code

Smartphone part

Just download this app from Google Play, and it will work. When connecting to the car choose the bluetooth device with the name linvor. If it asks for code, use 1234.

I hope this tutorial could help you. If anything unclear, feel free to comment.

Best regards:
Mark