Wireless Remote Controlled Car (RF 434 Mhz) : DIY 29

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This project “Wireless Remote Controlled Car” is an enhancement on the “Wireless Remote Controlled Circuit. It is very useful to study the features of wireless communication for electronics students or hobbyists. 

In our project we are designing an Wireless remote control based on Radio Frequency (RF 434 Mhz). For that we are using a RF transmitter receiver module. RF module is used as the remote transmitter & receiver, two IC’s HT12E & HT12D is used for Encoding and Decoding.

Circuit diagram and explanation given below will make you confident enough to make a remote control car.

Block Diagram for Wireless Remote Controlled Car

Here is a flowchart to help you understand the working logic of the wireless remote controlled car. First we will go over the basic idea of the RC car and the working logic that is involved in the car.

There are two blocks, the Transmitter (wireless remote control) and the Receiver (robot car).

wireless remote controlled robot

On the transmitter remote side, we have the switches to give the digital inputs to the HT12E encoder IC. The encoder then encodes this data and sends it to the the RF Transmitter module.

On the receiver side, we have the RF Receiver module which receives the encoded data and passes it on to the decoder. The decoder decodes the data and sends it to the L293D motor driver IC to drive the motors.

Transmitter Section – Remote

wireless car transmitter circuit

We have used 2 x DPDT switches to move the car backward, forward, left and right. Along with the switches we have used LED’s to indicate what data is being transmitted from the remote. 

HT12E Encoder IC: It is a 212 series encoder IC used for wireless communication applications. It is mainly used to convert 12 bit parallel data (8 address bits and 4 data bits) to serial out so that it can be transmitted using a transmitter Module.

RF Tx Module: 434 MHz ASK transmitter module for transmission. It is capable of providing a data rate of about 8 kbps. It is one of the cheapest wireless modules available in the market. 

Power Source: 9V Battery with a standard LM7805 based Power Supply circuit


Receiver Section – Receiver with Motor Driver & Motors

wireless car receiver circuit

RF Rx Module: A high sensitivity 434 MHz ASK Receiver module for receiving the data from remote control.

HT12D Decoder IC: It is a 1212 series decoder IC used for wireless communication applications. It converts the serial input to parallel out.

Motor Driver: L293D motor driver is used to drive two motors. L293D provides bidirectional drive current up to 600mA at voltages from 4.5V to 36V.

Motors: You can use 2 x BO Motors or 4 x DC Geared Motors, which are driven by the motor driver L293D and both of them are connected to robotic wheels to move the car.

Battery: Receiver section need more power than the remote control circuit. So 9V/12V battery is required to power the circuit.

Components required :

A) Motorized Structure : Assembling video here.
1) 4 x DC Geared Motors : 100/200 rpm (Buy here)
2) 4 x Compatible Tyres (Buy here)
3) 1 x Chassis (Mechanical body) (Buy here)

B) RF Circuit (434 Mhz)  : Circuit Video here.
1) 1 x RF Module Tx + Rx (434 Mhz) (Buy here)
2) 1 x HT 12E (Encoder) + HT 12D (Decoder) + Resistors (1M,50K) (Buy here)
3) 1 x General Purpose PCB (Buy here)
4) 2 x 7805 Based Power Supply Circuit Components (Buy here)
5) Switches (Buy here)  + LED (Buy here)
6) 2 x DPDT Switches (Buy here) : How to use video?

Buy assembled RF circuit with all the components here.

C) Motor Driver Circuit : Usage Video here.
1) 1 x L293D Motor Driver Module (Buy here)

D) Optional
1) Power Source (Battery with Snapper/DC Adapter) : 9-12V DC (Coming Soon)
2) Tools (Buy here)
3) Jumper Wires (Buy here)

Circuit Diagram (Remote Section)

Circuit Diagram (Receiver Section)

In case of any questions or queries, feel free to post below.

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  1. Nyc job sir but I want it

  2. Nice project I need assembled kit how can I purchase this please rly

    1. Do you need the working project or will you assemble it yourself? Please reply on [email protected]

    2. use links for buying required items in description

  3. Sir can you say me about +and– terminal of the both cicuits

    1. + Terminal = 5V,- Terminal = GND
      What other information do you need?

  4. I wanted to make a RC Car like this. I got Transmitter Receiver Circuit. Everything working fine but when i turn Receiver on Power LED turns on and 4 LED s glow and after a few seconds they goes off.Link LED not glowing. Please anyone help.

    1. Transmitter End LED s are working fine but i dont know either they are only glowing or transmitting some data.

      1. The way to check if there is data communication is to check if the link LED is on. Link LED is On when the Tx and Rx circuits are working fine.

    2. Dear Archit,
      The circuit on this blog is a verified circuit. To debug your circuit :
      1) Double check connections using Multimeter.
      2) Ensure that the Antenna on Tx and Rx RF Modules is atleast 15 – 20 cms.
      3) Make sure Power Supply is proper and connected at all required points.
      4) Try changing the Encoder Decoder IC or RF modules.
      Keep on trying till it works.
      It took us 15 days 5 years back to make our first RF circuit work so you’ll need to put in efforts.

  5. please where can i get all the circuit diagrams?

    1. Hello,
      There are links for circuits just after components required. Kindly go through the description again.

  6. In circuit diagram an arrows ends many time in power supply and other etc connection hence say where to connect those ends

    1. All the Vcc or 5V or GND have to be connected together. They have been mentioned separately to avoid complicated circuit diagram.

  7. Sir,
    The open circuit output voltage through decoder is coming 5V. And when I switch on the switch on Transmeter it turning to zero… That means the circuit is ok… But when I shorted with motor or led, the multimeter showing 1V … What is happening…

    1. Dear Saurab, ensure you have used a resistor with LED or Transistor with Motors as the output current is not strong enough to drive a motor directly.

  8. I need recover and transmeter rate

    1. Hello, its given in the buy links.

  9. articolo perfetto grazie

    1. Gracias

  10. Sir I have assembled the kit but there is a problem, as I push the button to run the motor it starts but dose not stop when I release the switch. it keeps on spinning. both channels are acting in same manner.

    1. This is usually a supply issue or noise from the motor. Ensure motor supply is adequate, or you are using a decoupling capacitor across motor.

  11. OM. Nice educational project.

    I bought the parts from BM embedded & tried first only testing individually the encoder decoder & 433MHz transmitter & Receiver.

    Testing the Encoder Decoder was easily successful. You just have to bias both the chips & connect output of Encoder to input of Decoder. Then you get a perfect Led blink as you push the buttons.

    However when I tried to test only the 433 Mhz Trans-Receiver, I struggled a lot for many days. I had connected the output of receiver to an LED & it kept blinking all the time, due to noise, even when I was not transmitting anything through the push button.
    The Key here is don’t try to test the Transreceiver individually. Always use it in combination with the encoder-decoder. The Encoder-Decoder is able to properly discriminate between noise & our sent signal (although we are not able to discriminate !). You get a perfect LED blink when you press the push button.


    1. Glad that you kept on trying and made it work. It took us 2 months to get our 1st 434 Mhz RF circuit working around 13 years back~!

  12. Circuit is working but sometimes motor keep spinning after releasing the drive switch, have to switch receiver circuit to stop motor, please suggest what mistake i am doing.

    Samar Singh Gaikwad
    1. Good to see that your circuit is working.
      The problem you have highlighted usually comes with motor drawing large current and system hangs. Try using the following steps :

      1. Ensure the receiver power source is strong enough to power the motors. If possible use a Li Ion rechargeable battery source.
      2. Ensure that the antenna is of appropriate length, and coiled properly.

      Let me know if this worked.

      1. In addition, I think you need to put capacitor across the motor, which bypasses the spikes. When an electric Motor rotates, it generates spikes that travel through both wire & wireless & can interfere with the RF Receiver circuit operation.
        Hence connect 0.1uF capacitor across motor terminals as close as possible & with short leads, as shown in the circuit.

        1. Hi,

          The decoupling capacitor are already connected to the Motor driver (check the schematic).

          Thank you.

          1. Sir,
            I have done as per your instructions, for some extend circuit is working OK,
            I have noticed that when we use both channels simultaneously then there is problem of continues spinning of motors. To stop the motors I have to restart the circuit.

            Samar Singh

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