This project consists in an automobile remote-controlled by a smartphoneusing Bluetooth. For communicate with Arduino we use a Bluetooth module and an applicationthat we found on the Play store for free.
We decided to buy a kit on amazon. The kit was made up of the chassis, two engines and the wheels. The two motors are screwed in the polycarbonate structure of the chassis. There are two motors in front of thechassis that control the traction and the steer. The small wheel is used like a support and it can move neutrally.
If you want you can use a servo to change the direction. You can also use some different motor driver like the pololu or theL293D.
If you do not use the small wheel you can use 4 wheels powered by dc motor. After that you must change the chassis of the automobile because there is not the space for two other wheels.
The automobile that we realise is capable to move forward and to steer by smartphone command using Bluetooth.