DIY Remote control car: The best RC car tutorial

DIY Remote control car: The best RC car tutorial

Remote control cars have been the dream toy for most kids. And you can never outgrow them! So In this article, I will show you an in-depth step by step procedure on how to make a simple Remote Control Car that operates in RF (radio frequency). This is a very simple and beginner level robotic project which can be made by anyone with interest. I will discuss the working of all integrated circuits (IC) and modules used dor this robot. And the best part for beginners is that there is NO programming required for making this robot!

Things you need

Power supply

First, Both the RF transmitter and receiver circuit requires a separate power supply. The receiver circuit would require 9-12v supply depending upon the motor you are using and the transmitter circuit can be powered using a 9v battery.

Voltage regulator 7805

The 7805 is a linear voltage regulator used to regulate 12v supply to 5v
To this pin, the positive of the unregulated power supply is connected. In my case 12V, It can go up to 35V according to the datasheet
The negative of the Input power supply.
This pin gives regulated positive 5V

Note

Use heat sink for 7805 because we are dropping 7v (12-5 )so lots of heat will be produced to burn the regulator so use heat sink is recommended

What is RF module ?

This RF module consists of an RF Transmitter and an RF Receiver. The transmitter sends data wirelessly and receives it through an antenna. To have a successful transmission both transmitter and receiver should operate at the same frequency. This module is used with a pair of encoder and decoder IC. The encoder is used for encoding data for transmission and in the reception, a decoder is used to decode the received data.

Some features of RF 433Mhz RF Module

  • Operating frequency: 434 Mhz
  • Operating Voltage : 3~5V
  • Data transmission rate: 1Kbps – 10Kbps
  • ASK Modulations.
  • Low Current consumption (5.5mA at 434MHz)

Working of the Robot

Pin Description RF module

Goes to the ground of the circuit
To this pin data to be transmitted is given, INPUT pin
Power supply for the module, 5V
To this pin, an external antenna can be attached to improve the range, Solder a single strander 20cm long wire to this pin.

RF RECEIVER

This Pin is to connect an external antenna to improve the range, connect 20cm long wire to it
Goes to the ground of the circuit
Power supply for transmitter it can be between 2.5-5V. Recommend 5V for a better range.
There are 2 data pins you can use anyone since both are internally connected. This pin is the output pin of the receiver.

Make the Transmitter (Remote)

 The transmitter circuit consists of an HT12E Encoder IC, an RF transmitter module and a pair of DPDT switch
In the above circuit, you can see A B C D label marked near the switch. In the below DPDT switch wiring illustration also I have mentioned A B C D label. Just connect the label in the transmitter circuit to the label in the DPDT wiring circuit. i.e A –> A, B –> B, C –> C and D –> D

HT12E Encoder

These pins are used to set address, It can be either set open or made high. The address combination should be the same for both Encoder and Decoder.
Goes to the ground of the circuit
These are the input pins. To this pin, we will be connecting the DPDT switches. It be left HIGH or LOW
TE stands for Transmission Enable. This pin needs to be made LOW (Grounded) to enable transmission.
These pins are to connect the external oscillator.
This is the serial output pin. This pin goes to DATA pin of the transmitter module
Positive power supply for the integrated circuit, 5V

Make the Receiver

The receiver circuit has got 2 integrated circuits (ICs) (HT12D decoder, L293D motor driver)and RF receiver module.

Wire the circuit as per the above receiver schematic. There are 2 led in the receiver board, one is power status, this turns ON when the power supply is provided to the receiver circuit. The other LED is connected to pin. This LED will turn ON if the receiver is getting a valid transmission. When the power supply is provided to the transmitter circuit this LED should turn ON, If not there is something wrong with your connection or your RF TX RX module.

Note: Use red wire for positive and black for negative if there is any problem with the circuit it will be easy for debugging the circuit

HT12D Decoder

This is the address input. Status of these pins should match with the status of the address pin in HT12E (used in the transmitter) to receive the data. These pins can be connected to VSS or left open

This is the data output pins. Status of these pins can be VSS or VDD depending upon the received serial data through pin DIN.
This pin is the serial data input and can be connected to an RF receiver output.
This pin is used to connect external resistors for the internal oscillator of HT12D. OSC1 is the oscillator input pin and OSC2 is the oscillator  output pin
 stand for Valid Transmission. This output pin will be HIGH when valid data is available at D8 – D11 data output pins.
 This pin is used to provide power to the IC, Positive and Negative of the power supply respectively:

Motor Driver

The L293D is a 1A Motor Driver IC that can drive up to 2 motors in bi-direction. This driver IC is dedicated to controlling the DC motor. It can control a set of 2 DC motors same time in any direction.
If you need more information regarding this integrated circuit please refer to the datasheet here

Pin description of L293D

These pins, when made HIGH, enables the driver channel 1 and 2
Input for the drive channel 1 and 2
Goes to the ground of the circuit and heatsink (if using)
To these pins, the left side motos are to be connected
  Power supply pin for the internal logic translation 5V
These pins, when made HIGH, enables the driver channel 3 and 4
Input for the drive channel 3 and 4
To these pins, the right side motos are to be connected
The power supply for the motor goes to this pin. 4.5v-36v

Decide the Motor Specification

Choosing a motor is very important and this totally depends on the type of robot you are building. There are many types of DC motors available with different specifications like the voltage, torque. If you have trouble choosing the motor. I suggest using 12V 200RPM geared motor.

Choose the right RPM for motor

In my case I have a 12V 300 RPM motor RPM, RPM stands for revolutions per minute, It is the number of times the shaft of a DC motor completes a full spin cycle per minute. You should be very careful while choosing the RPM. Don’t go for higher rpm cause it will be difficult to control it since this model of robot doesn’t have speed regulations. Remember SPEED IS INVERSELY PROPORTIONAL TO TORQUE

DEBUGGING (OPTIONAL, If your robot isn’t moving).

In this part, I will be discussing on how to debug the circuit. First of all, don’t be angry, just keep calm. We will go for split and conquer. We will split the circuit into different parts.

Motor Driver

For debugging the L293D IC. Place the IC on a breadboard and provide power supply +5v to and Gnd to and connect +12v to pin 8 . Connect a motor to &. Connect both the enable pins & to 5v. Now connect 5v to and connect to the ground of the circuit. If everything is proper the motor should rotate and if the connection to & are inverted the motor should rotate in the opposite direction. Do the same with the other side.

Power Supply

Use a multimeter and put in continuity mode, and check for any short circuit between positive and negative pins. Check if all the ICs are getting proper voltage. Make sure all the GND pins are properly grounded.

Decoder and Encoder (HT12E/Ht12D)


You can check if your decoder and encoder are working properly without using the RF module pair. Connect pin 7 of HT12E to pin 14 of HT12D, Connect push buttons at pin 10,11,12,13 of HT12E and connect 4 LEDs at pin 10,11,12,13 of the decoder ( connect as per Decoder and Encoder Debugging circuit ) The LEDs should light up when switches are pressed
If your robot is still not working then there would be a problem with the RF module and so try replacing the module.

131 thoughts on “DIY Remote control car: The best RC car tutorial

  1. A small change…. In the transmitter circuit, we actually need to ground pin 14 and connect pin 17 to the data pin of the TX (transmitter).
    But hats off to the project. Thanks Mayoogh for the circuit diagram. I made it.

  2. Hii I am Anand Joshi from India.
    First of all this is great work by you. I am planning to make this car. I have to ask from where I can get those wheels like yours? And what is better between adding 2 nine volts battery on car or adding a single 12 volt battery on car?
    Your explanation would be really helpful.
    Thanks for sharing this great stuff in this neat manner. Thank u alot.looking forward for your answer. 🙂

  3. I am using 12 volt 1.3 A battery.which charger should I use? Please provide link if it is possible for you. Should I connect radio antennas to the wire of transmitter and receiver?

  4. thanks MAYOOGH GIRISH this is the best tutorial i have seen of rc car with well define schematic n images and every thing… thumbs up !!
    n one more thing u r so helpful man.. #sucessfuly made RC CAR

  5. hello in the dpdt switch connections where to connect the ground??. I mean that the dpdt switch connections u have shown has only A<B<C<D pins. where is the ground pin in the dpdt switch connection u have shown??

    1. You need to connect gnd of dpdt switch to the gnd of the transmitter circuit (connect to negative of circuit/middle pin of 7805) and Vcc to the positive of the circuit(third pin of 7805/outputpin)

      1. Now it’s not heating ,but when I supply give supply to receiver motor on pin no. 14 starts rotating even I don’t give signal to pin no.14,other motors works properly.

  6. ## is 1M mean absolutely 1M . I have 100k resistance . can i use them ??

    ## can i use fs1000A tramsmitter receiver . where receiver has only 4 pins ??

    1. No, 1M is recommended one.
      There is noting to worry if you have a fs1000A module. the module used here have same pins (Data, Vcc, Gnd, Ant) as yours fs1000A module. The other module just have multiple gnd and vcc pins

    1. No servos are used here , the car turns when the wheels on the either as side rotates in different directions,ie the motors on the left side will rotate forward nd motors on right side rotates backwards nd vice versa

    1. No servos are used here , the car turns when the wheels on the either as side rotates in different directions,ie the motors on the left side will rotate forward nd motors on right side rotates backwards nd vice versa

  7. hey i am actually working on the same project that you made well i was successfully able to transmit and receive the data but was not able to get proper out put from the l293d and may i know how many batteries and how much total voltage is used on the receiver or say the vehicle side??and after seeing your circuit diagram i got few doubts, first of all we need to use decoder on receiver side and connect it to motor driver right?? as encoder HT12E converts the parallel inputs into serial output. It encodes the 12 bit parallel data into serial for transmission through an RF transmitter and the reverse case happens with decoder.

    1. The receiver circuit can be powered by either 9v or 12 (since we have using 7805 voltage regulator) depending upon the voltage of your motor ,
      The l293d 8th pin should be given 9/12v , that is the motor voltage supply pin

  8. Hello, great work. I am very passionate on making this types of gadgets on my own. I don’t understand where to start from. Can you please help me?

  9. Actually I’m an absolute beginner to these kinds of things. This tutorial is very good. But I really don’t understand the thing called “ground” (GND).Can you please tell me what is that? And what should I do with that? Please !

  10. Thanks for the previous explanation. But now I have another problem. Actually what are those things called ‘4 bit address’ and ‘8 bit address’ ?It’s really confusing. In the HT12E pin description pin(1-8) are for 8 bit address pin for output and pin 9 is for gnd. But in the transmitter circuit all of the 9 pins are connected to GND. please help me to solve it.

  11. Your tutorial is the best tutorial that even a beginner like me also understand it. I understood everything except one thing. Where do the wheels go? I meant there are two circles called m1 and m2 and I believe that is motor 1 and motor 2. Is ‘m1 and m2’ for the 2 wheels of back or is it for all the four wheels (1 for 2 wheels and other one for other 2 wheels) ?

  12. Is it a good idea to use a DC Motor on each rear wheel and a servo to control the freely moving front wheels assembly for steering? Can this be achieved with same RF Module, HT12E Encoder Decoder and L293D driver ? Appreciate your time. Thanks

  13. hello sir .. why only one motor move at one time in 1 ic l293d ..why cannot run both motor simultaneously..vcc2 i use 12v. and i want to know ..do you use 2 l293d ic for 4 motor or only 1 ic thank you sir

      1. If i take out left motor the right motor will run..if take out right motor the left one will run..that mean only one motor can run at one time .. What does that mean ? My vcc not enough ? Sory for bad english sir thank you

  14. hello sir .. why only one motor move at one time in 1 ic l293d ..why cannot run both motor simultaneously..vcc2 i use 12v and do you use 2 l293d ic to control 4 motor or just one ic ..thank you

  15. Hello sir .. Why only one motor run at one time in one l293d ic cannot run them simultaneously..vcc2 12v and do you use 1 l293d to control 4 motors ?

  16. Hello sir..my problem before solved..my suplly for motor not enough i need 8 AA bat or can u recomend me type of bat to supply for motors..next problem i dont understand how u drive 4 motor ..do you use 1 ic l293d and 4 motors by parallel the motor ? Sory for bad english thank you ^^

  17. Im a 6th grader that goes to a school for the gifted and talented and I used this for my project and I got a A, I also added some more touches, like a camera and a protective sheet for it.

  18. Hello, I want to help you a little. I can give you the pcb diagram of these two circit boards. At ptesent, it is very confusing. It will make easy to make the circuit.

    1. I have bought L293D ic. But, It’s not attached on a pcb. It’s separate ic. Is it ok? Its not looking like you.

      In 5v regulating circuit, which capacitors should I use? Somewhere you have written 10uf and 100uf, whereas somewhere you have written 0.1uf. I am confused.

      Also, can I use 3 batteries of 4v instead of 12v battery?

      Can you upload clear image of Receiver circuit. Or send it on my email pls.

    1. Do I need to place VCC in dpdt switch also, or only negative. Because you have not connected VCC in circuit diagram but in switch connection diagram, you have connected.

  19. In the recieve section HT12D should be used in circuit. But it’s written HT12E with pin labelling as that of HT12E but I think the connection is correct with respect to pin numbers of HT12D. Please correct the error

  20. I have almost completed the car but recently faced a problem:
    When I press A, the motor turns but when I release the button, the motor doesn’t stop and the connection led also turns off. I have read on internet. It may be due to noise produced by motor. But I need a professional answer from you. What can I do?

  21. Which motor is to be used 6v or 12 v because output for motor is about 5-6 v n u mentioned 12 v dc motor.
    Also I’m facing problem ie when I push button A it starts turning.it doesn’t stops n led also off
    How to overcomethis problem please help

  22. “”””For debugging the decoder and encoder IC connect pin 7 of HT12E to pin 14 of HT12D ,Connect push buttons at pin 10,11,12,13 of HT12E and connect 4 leds at pin 10,11,12,13 of the decoder”””””
    BUT IN THE DEBUGGING CIRCUIT YOU DIDN’T CONNECT ANY PIN OF THIS STYLE

  23. I want to add head lights to the car . So, i need an ic pair capable of encoding and decoding 6 signals. Can u tell me which ic pair should i use?

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