Remote control car
Remote control cars have been the dream the toy for most kids. And you can never outgrow them! In this post, I will show you step by step, 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 be discussing on the working of all integrated circuits (IC) and modules used in this robot. And there is no programming required for making this robot!

Watch the robot inAction   🙂   😀

Stuff you need to make the robot (Rc Car)

Make the power supply

First we will start with the power supply circuit. Both rf transmitter and receiver circuit need separate power supply The receiver circuit need to powered using 12v supply and transmitter circuit can be powered using 9v battery
Power supply

1 (1)

  1. Pin 1 — Input voltage (5v-18v ) [V in]
  2. Pin 2 — Ground [gnd]
  3. Pin 3 — Regulated Output (4.8v – 5.2v]
  • IC 7805 which regulates the 12v supply to 5v (if cant get a 12v supply you can use a 9v supply)
  • 0.1uf & 470uf capacitor
  • And 1k resistor for status led

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 ?

433mhz rf transmitter and receiver

This RF module consist of an RF Transmitter and an RF Receiver. The transmitter/receiver (Tx/Rx) pair operates at a frequency of 434 MHz. An RF transmitter receives serial data and transmits it wireless through RF through its antenna connected at pin 4. The transmission occurs at the rate of 1Kbps – 10Kbps.The transmitted data is received by an RF receiver operating at the same frequency as that of the transmitter. The RF module is used along with a pair of encoder and decoder. The encoder is used for encoding parallel data for transmission feed while reception is decoded by a decoder. HT12E-HT12D

Working of the Robot

The RF module is used along with a pair of encoder and decoder. The encoder is used for encoding parallel data for transmission feed while reception is decoded by a decoder. HT12E-HT12D


Pin 1 — Ground [GND]

Pin 2 — Serial Data Input Pin [DATA]

Pin 3 — Power supply; 5V [Vcc]

Pin 4 — Antenna output pin [ANT]


Pin 1 — Ground [GND]

Pin 2 — Serial data output pin [DATA]

Pin 3 — Linear output pin (Not connected) [NC]

Pin 4 — Power supply;5v [Vcc]

Pin 5 — Power supply;5v [Vcc]

Pin 6 — Ground [GND]

Pin 7 — Ground [GND]

Pin 8 — Antenna Input pin [ANT]

Make the Transmitter (Remote)

RF transmitter circuit_

 The transmitter circuit consist of
  1. HT12E encoder
  2. RF transmitter module
  3. Two DPDT switch
  4. and 1M resistor

You can see i have marked A, B, C, D in the transmitter circuit after the switch and see the DPDT connection diagram below there also you can see i have marked A, B, C, D. Connect A,B,C,D on the transmitter circuit to A,B,C,D on the 2 DPDT switch.
The DPDT switch connections is shown above.



Pin (1- 8) — 8 bit address pin for output [ A0,A1,A2,A3,A4,A5,A6,A7 ]

Pin 9 — Ground [ Gnd ]

Pin (10,11,12,13) — 4 bit address pin for input [ AD0,AD1,AD2,AD3 ]

Pin 14 — Transmission enable , Active low [TE]

Pin 15 — Oscillator input [ Osc2 ]

Pin 16 — Oscillator output [ Osc1 ]

Pin 17 — Serial data output [ Output ]

Pin 18 — Supply voltage 5V (2.4V-12V) [ vcc ]

A0-A7 — These are 8 bit address pin for the output.

GND — This pin should also be connected to the negative of the power supply.

TE — This are the transmission enable pin.

Osc 1,2 — These pins are the oscillator input and output pins.This pin are connected to each other with a external resistor.

Output — This is an output pin. The data signals is given out from this pin.

Vcc — The Vcc pin connected to positive power supply, It is used to power the IC.

AD0 – AD3 — These are the 4 bit address pins.

RF Receiver circuit
The receiver circuit consist of 2 IC(HT12D decoder , L293D motor driver),RF receiver module
Wire the circuit as per the above receiver schematic. There is 2 led in the receiver board ,one lights up when power supply is given to the receiver and the other when power supply is given to transmitter circuit the led near the IC HT12D should lit and this provides you a valid transmission(VT) when power is given at the transmitter 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

PIN DESCRIPTION FOR HT12D ht12dVDD and VSS: This pin are used to provide power to the IC, Positive and Negative of the power supply respectively

DIN: This pin is the serial data input and can be connected to a RF receiver output.

A0 – A7: This are the address input . Status of these pins should match with status of address pin in HT12E (used in transmitter) to receive the data. These pins can be connected to VSS or left open

D8 – D11: This are the data output pins. Status of these pins can be VSS or VDD depending upon the received serial data through pin DIN.

VT: stand for Valid Transmission. This output pin will be HIGH when valid data is available at D8 – D11 data output pins.

and OSC2: This pin are used to connect external resistor for internal oscillator of HT12D. OSC1 is the oscillator input pin and OSC2 is the
oscillator  output pin
L293D (Motor Driver)
The L293D is a Motor Driver IC it allows the motor to drive on both direction. L293D is a 16-pin IC with eight pins, on each side, dedicated to the controlling of a motor which can control a set of two DC motors at a same time in any direction. With one L293D we can control 2 dc motors ,There are 2 INPUT pins, 2 OUTPUT pins and 1 ENABLE pin for each motor. L293D consist of two H-bridge. H-bridge is the simplest circuit for controlling a low current rated motor.
l293d (

Pin 1 — Enable pin for motor 1 [Enable 1 ]
Pin 2 — Input pin 1 for Motor 1 [Input 1 ]
Pin 3 — Output pin 1 for Motor 1 [Output 1]
Pin 4,5,12,13 — Ground [ GND ]
Pin 6 — Output Pin 2 for Motor 1 [ Output 2 ]
Pin 7 — Input pin 2 for motor 1 [ Input 2 ]
Pin 8 — Power supply for motors(9-12v) [Vcc]
Pin 9 — Enable pin for motor 2 [ Enable 2 ]
Pin 10 Input pin 1 for motor 1 [Input 3 ]
Pin 11 Output pin 2 for motor 1 [Output 3]
Pin 14 Output 2 for motor 1 [ Output4 ]
Pin 15 Input 2 for motor 1 [ Input 4 ]
Pin 16 supply voltage ; 5V [ Vcc1 ]

Choose the right motor

Choosing a motor is very important and it totally depends on the type of robot (car) you are making if you are making a smaller one use 6v Bo motor If you are making a larger one which need to carry heavy load then use an 12v dc motor


I have 12V 300 RPM motor RPM, which stands for revolutions per minute, is the amount of times the shaft of a DC motor completes a full spin cycle per minute. A full spin cycle is when the shaft turns a full 360°. The amount of 360° turns, or revolutions, a motor does in a minute is its RPM value. You should be very careful while choosing the rpm don’t choose motors of higher rpm cause i will be difficult to control it and remember SPEED IS INVERSELY PROPORTIONAL TO TORQUE

DEBUGGING (OPTIONAL, if there is problem with circuit)  FPQY2VSHWU4Q4DZ.MEDIUM
In this session i will be discussing on debugging the circuit First of all don’t be angry just keep calm for debugging we will split the circuit in different First we will be debugging the
L293D IC
Place the IC on a bread board and give 5v and Gnd to the IC and then give the 12v to pin 8. connect the enable pins of the motors to 5v .Now give power to the input of one motors and check the output pins with a multimeter. If it shows nothing then there is problem with you motor driver
Most of the problems arise in the power supply circuit is due to short circuit so for checking power off the circuit and use a multimeter  to check whether there is any connection between Negative and positive

ht12d debugging
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 ( connect as per Decoder and Encoder Debugging circuit [fig 3]) The leds should light up when switches are pressed
If your robot is still not working then there would be problem with the RF module and so try replacing the module.


116 Comments Add yours

  1. Amaan says:

    Brother how to connect power circuit to TRanstmiter and receiver circuit . plz reply soon…


    1. Just connect the +5v output to all 5v in the transmitter and receiver circuit and and gnd the similar way


  2. Amaan says:

    Brother You told that you use 4 motor but in digram 2 motors r used . what I do , I am confused
    Reply soon as posible


    1. The two motors in one side is connected in parallel to each other


  3. Lester says:

    hi there do i need to replace my l293d because only one channel is working or is there a solution for it?


    1. If you are sure that one channel is not working then you need to replace the motor driver

      Double check all the connection, and also check both the Enable pins


  4. Lester says:

    thanks,i change the motor driver and now its working.what voltage and ampere range did you use with your project?


  5. Yash Mittal says:

    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?


  6. Yash Mittal says:

    How to make antenna of the car. Its not catching the signal. How have you drived your car without antenna?


  7. sarvjit says:

    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 doesn’t stops n led also off
    How to overcomethis problem please help


    1. Check the baud rate of serial monitor . Check whether it is 9600


  8. Akshita Girish says:

    Can I use 12v 0.5ah battery?


  9. tharun says:

    hi bro
    which one i have to use
    HT12E encoder
    HT12d decoder
    is it HT12E encoder or HT12D encoder


    1. Both are required
      Ht12d is for receiver circuit and ht12e is for transmitter circuit


  10. Srikar says:

    “”””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”””””


    1. Sorry for the inconvenience caused its 17. Not 7


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