I love remote control vehicles, they are super fun and interesting. In this Instructable I will show how I created my own bluetooth car using Arduino and some parts I had lying around. This Instructable is in theory only, the car did not end up working exactly how I had planned it, but next year I will continue and may be back to update it when its complete.
Step 1: Collect Your Materials
These are all the parts you will need in order to complete this project. If you don't have the exact parts or motors, others could be substituted in for them, but just be warned it may not turn out just as mine did.
-USB/Arduino Power Cable
-HC-06 Bluetooth Module
-9V DC Motor
-2 9V Batteries
-2 Battery Snaps
Step 2: The Circuit
Here is a schematic of the circuit and a picture of the circuit that I built. Let's build it in steps:
-First connect the power and ground of the Arduino to the power and ground on the left side of your breadboard
-Next connect the first battery snaps power and ground to the right side of the breadboard. Connect the other Battery snaps power to the Vin pin on the Arduino, and the ground on the battery snap to ground on the Arduino.
-Connect the servo motor's power pin to the 5V on the left side of the breadboard, the ground pin to ground on the left side of the breadboard, and the center pin of the servo motor to pin 9 on the Arduino. The center pin is the one that will allow us to control the angle that the servo is set at.
-Connect VCC pin of the HC-06 Bluetooth Module to 5V on the left side of the breadboard, and the GND pin to the ground on the left side of the breadboard. Refrain from plugging in the TX and RX pins until you upload the program onto the Arduino board, because the board will not accept the program while those pins are plugged in. After you have uploaded the program to the Arduino plug the TX pin of the HC-06 into the RX pin of the Arduino, and the RX pin of the HC-06 into the TX of the Arduino.
-Next in line is the motor. Because the Arduino only produces a maximum of 5V it is not enough to propel the card forward, however we still need to be able to control the motor using the Arduino. We will do this using a component called a MOSFET transistor. The MOSFET has 3 pins, a gate, a source, and a drain. As you can see from the picture, when we apply 5V to the gate, power will be able to flow through from the drain to the source. With this in mind we will connect the gate pin of the MOSFET to pin 6 of the Arduino, reference the picture to make sure you are connecting the right pins. This will allow us to link the other 2 pins of the MOSFET together by putting power out of pin 10. Next connect the source of the MOSFET to ground on the right side of the breadboard. Then connect one end of the motor to the drain pin on the MOSFET, and also connect a diode from the drain pin to the power bar on the right side of the breadboard. This diode in parallel will stop something called back-voltage. When a motor spins around it creates electricity like a generator, and this electricity can flow in the opposite direction that the circuit is running. This can cause problems, and in order to stop the electricity from doing this we need to insert a diode in parallel with the motor. Now connect the other end of the motor to the power bar on the right side of the breadboard. You may need to reverse the motor connections if you realize the motor is spinning the wrong direction for your car. Keep this in mind when you start testing the car.
Step 3: The Program
This is the program we will be putting on the Arduino Uno in order to control the car. Download this and open it in the Arduino IDE. We will upload this to the Arduino board in order to control the car.
Step 4: Creating Car Base
So this part will vary greatly. I have attached a picture for that shows what I came up with, but really all you need is a freely spinning axle with 2 back wheels, a front wheel that can be attached to the servo motor, and a platform above or in between that can house the circuit board and breadboard. The motor also needs to be able to be attached to the rear axle by an elastic band so that the back tires can spin.
Step 5: Assembling It All Together
Basically you just attach the circuit board and breadboard together in a package, and attach it to the platform made in the previous step. Hook up the motor to the axle with an elastic band and then your almost set.
Step 6: Getting the App
You need an Android phone for this to work, and then you go into google play and find the app called "Smart Bluetooth". Connect this to the HC-06 Bluetooth Module and your good to go!