Bluetooth Controlled Robot Car




About: Enthusiastic! Bussiness freak :P

were you always fascinated by RC cars ?

Ever wanted to make one yourself ? controlled by your own smartphone ? ----> lets start

So, hey guys, here in this project i have tried to make a Bluetooth controlled car with the help of Arduino. I have included each detail so you can understand it easily. Also you can watch the video which is more detailed. Watch it till end and you will learn to make it within 10 minutes.

I have added every circuit diagram and explanation possible to make it easy for you all to understand.

It is economical and is a good idea for your school / college project. You don't need any previous knowledge!

just follow this guide :P

Step 1: Materials Required

1. Any car chassis kit ( with BO motors, wheels and base )

I bought this kit-

2. Arduino UNO

3. L298 motor drive

4. Hc-05 bluetooth module

5. two batteries ( I used Samsung 18650 rechargeable cell , 3.7V and 2600 mA both) Link:

6. Jumper Wires

7. Electrical instruments ( Solder wire and iron )

8. mobile with bluetooth

Step 2: Solder All Motors & Attach Them to the Base

Solder each motor with a black and a red wire and attach them with the chassis as shown in the video.

join left side motor wires together as: red wire --> red wire and black wire --> black wire

similarly join motors on right side together as: red wire --> red wire and black wire --> black wire

Step 3: Join Wheels to All the Motors

don't apply too much pressure while pressing the wheels otherwise the chassis may get break.

Step 4: Join the Two Batteries in Series

Connect the batteries in series by joining with a tape. You can also keep a little piece of open wire between them so that they are well connected.

Now join red wire to positive terminal of battery and black wire to negative terminal.

Try to keep the voltage <= 9 volts. I used 2 batteries of 3.7 V so my total pack voltage was 7.4 volts. If you use to high voltage ( like >= 12 volts , there is a chance that your components will get heated and might burn )

If your batteries have more current rating- your motors will rotate fast. My battery current rating was 2260 mA which was enough to power 4 motors.

Caution: Don't accidentally connect positive terminal of battery to its negative terminal directly. It might burn your wires without any resistance.

Step 5: Connect Motors to Motor Drive

Join the red and black terminal of motors on each side, to the motor drive outputs.

Step 6: Connect Motor Drive to Arduino

Then join the four control pins of motor drive to the arduino 9th, 10th, 11th and 12th pin socket.

Step 7: Join Bluetooth Module to Arduino

Connect bluetooth module( BT ) HC-05 to arduino as shown in circuit diagram.

join BT module to arduino as: VCC --> 5V and GND --> GND

Step 8: Connect Motor Drive to Battery

Connect motor drive's power input socket, to positive and negative terminal of battery. also connect the negative terminal of battery to GND of arduino. Finally connect 3rd terminal to Vin of arduino.

You can also add a switch to start or stop the car as you wish.

Step 9: Upload the Code & Download the App

You can copy the code from here.

Now compile and upload the given code to the arduino.

Step 10:

After uploading, disconnect the arduino from pc.

Now connect Rx of Hc-05 to Tx of arduino and Tx of Hc-05 to Rx of arduino.

(do not connect these before uploading the code otherwise it may burn your arduino while uploading the code)

Finally, download the Arduino Bluetooth control app.

Step 11: Pair With Bluetooth Module

Start the Car. Check that the LED of Bluetooth module is blinking fast without pairing.

Pair the HC-05 Bluetooth module with your smartphone. Enter password 1234. ( if it not works try 0000 )

After pairing open the app and choose HC-05 to pair with. Check the LED of Bluetooth module, its blinking rate would have been very slow now.

Step 12: Test Drive

Go to App --> Buttons

Press 1: Car moves forward. ( all wheels start moving forward )

Press 1: Car moves in reverse. ( all wheels start moving backward )

Press 3: Car turns to left side. ( Only right wheels move )

Press 4: Car turns to right side. ( Only left wheels move )

Step 13: Suggestions

make all your connections correct and tight. If they are loose then your car can stop while moving.

You can even build a obstacle avoiding robot as your next project.



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    14 Discussions


    Question 4 days ago on Step 12

    I am not able to upload this code on my Arduino bored got error messages


    Question 5 months ago

    I have connected as you did. But light is not blinking in my Bluetooth module (HC-05)

    3 answers

    Answer 5 months ago

    is it not blinking at all, or its blinking for some time and then stop? is your bluetooth module fine?


    Reply 17 days ago

    In my case only light's of arduino and motor driver are blinking ... when i connect to pc all lights are blinking what is the problem?


    Question 6 days ago on Step 8

    How does the arduino uno blinks?????


    Tip 7 days ago on Step 8

    How did you connect the switch to the robot?????????


    Question 10 days ago

    I have 2 gear motor and only one wheel rotates and other does not rotate and the progaramming code says error what's the matter please help me as much as possible i have got competition soon


    17 days ago

    In my case only light's of arduino and motor driver are blinking ... when i connect to pc all lights are blinking what is the problem?


    8 weeks ago

    I have got the exact components and wired everything mentioned here. I am able to connect to BT using app and all the lights are working. The indicator light (orange) blinks differently whenever a command is sent from app. However, the wheels do not move a bit. I tried by lifting the car up thinking it will unload the wheel from the motor and chassis weight. Nothing allows to turn the wheel. Can someone think of anything that I might have missed? Thanks.



    2 months ago

    I want to ask you can I use mega 2560 inside of uno


    Question 2 months ago

    is it possible to combine your car with obstacle avoiding sensors HC-SR04, so when you move the car, let's say forward and it detects a wall, it will go into reverse and then L or R and what would be the sketch to integrate ?