How to build a Remote control ( RC ) car at home

model-rc-car

Remote control Cars also known as RC cars are something every electronic hobbyists would love to build. But most of them didn’t know where to start and how to build it, some even got deceived by its complex looks. This article is focused to guide hobbyists to build their own homemade RC car with minimal components.

BLOCK DIAGRAM:

block-diagram-of-rc-car

To build a RC car we need to make sure that these blocks are available. The above blocks are divided into two sections Remote and Car for the purpose of understanding. Starting from Keypad which controls the movement of the Car whereas Encoder and decoders are meant to encode and decode the movement signals for secured transmission. Transmitter sends the movement signals through wireless medium and receiver fetches the signals for the destination.

CIRCUIT DIAGRAM OF REMOTE CONTROL:

rc-car-remote-control-circuit-diagram

The above Remote control Circuit consists of three important components Keypad, Encoder IC HT12E and a RF Transmitter RF433 module.

KEYPAD: The Keypad for our remote is made up of four individual buttons which is wired to the data pins of the data pins AD0 to AD3 of the encoder IC. When these buttons are pressed it passes the movement signals to the encoder,

ENCODER HT12E: This encoder serves the purpose of encoding the movement signals fed by the individual buttons. The Data pins AD0 to AD3 is active low hence pressing the button closes the circuit and a logic 1 or high signal is fed to these pins. It also contains Address Pins A0 to A7 which allow us to try out different address combinations for secured transmission of data but make sure you use the same address combination in the receiving end (decoder). In the above circuit we did’t try out any address combinations hence all the pins are grounded. The Dout Pin gives the encoded output data. Read more about the Working of HT12E Encoder.

RF433 TX: This is a simple RF433 TX module which operates at frequency at 433MHz. The encoded data from the Encoder is fed into DIN pin of the TX and a simple antenna is attached to its 4th pin.

CIRCUIT DIAGRAM OF REMOTE CAR:

rc-car-remote-control-circuit-diagram

RF433 RX: This a simple RF433 RX module which operates at 433MHz. The received encoded data signals is received through the antenna and the signal is obtained from DATA pin to feed the decoder.

HT12D DECODER: The encoded signals from the RX module is fed into the DIN pin of the decoder. The signal is then decoded by the decoder, remember to use the same address combination used in the encoder if any otherwise the movement signals will be interpreted incorrectly. The decoder also consists of VT pin which serves as a identification if any RF link is established, LED was connected to this pin for identification.

L293D: This IC serves as a Bidirectional motor driver. It is highly impossible to drive heavy loads such as motors using decoder IC hence we have used a dedicated L293D IC for this purpose. Read more about the Working of L293D.

MOTORS: Two simple DC motors are used for the movement of RC Car. A motor for moving the Car forward and backwards whereas the other one is used to steer the car left and right.

MOVEMENT MECHANISM OF RC CAR:

We are done with the Remote control and the circuits which is about to be placed inside the car. Now next important thing is provide mechanism to move our RC car front and back. This can be done by fixing a gear to the motor and to the rail which connects the rear wheels. Fix the motor close to the gear in the rail so that when motor makes a movement the car moves forward. Likewise when the motor rotates in the opposite direction the car should move backwards.

STEERING MECHANISM OF CAR:

Steering mechanism is bit tricky than the movement mechanism since it requires bit of mechanics. There are several Steering mechanisms used in building RC cars but here i prefer to use “Rack and Pinion” arrangement to steer the car in our desired direction.

rack-pinion-arrangement

Image Courtesy : www.offroaders.com

The above animation shows the working of Rack and pinion steering mechanism. Here the pinion gear will be attached to our front motor which is responsible for Right/left steering. When this motor moves in clockwise direction the car turn left and vice versa. See the working this gear arrangement in this video.

PARTS NEEDED:

NAMEQUANTITY
RF433 MHz TX and RX1,1
Encoder HT12E and Decoder HT12D1,1
L293D1
Motors2
Wheels4
ResistorsAs required
LED1

You can buy the above components at affordable price from Amazon with ease below. We are an affiliate partner of Amazon.in, you could do a favor for us by buying these compoenets using the link provided below.

PCB LAYOUT:

pcb-layout-rc-car-remote

PCB layout RC remote

pcb-layout-rc-car-body-board

PCB layout of RC car

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Frank Donald

Frank Donald

Junior Network Engineer at Tata Communications
Frank Donald is an Electronics and Communication Engineer who loves building stuff in his free time. Video games, blogging and programming are the things he loves most
Frank Donald

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Anonymous
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Anonymous

how to create rc 4 channels

Anonymous
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Anonymous

You giving only 5V to receiver circuit but is it capable to drive 12V do motor.

kiran
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kiran

What are the alterations needed to run 2 servo motors ( for proportional steering and speed control) ?

shankar
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shankar

if it is difficult How can i confirm that where my car is going if it goes out of visual range

shankar
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shankar

how can i connect an camera

Anonymous
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Anonymous

Can we connect it via Android mobile bluthooth?

dadafafraafa
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dadafafraafa

how to download this schematic? for altium

Krishan
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Krishan

The circuit is working fine, I tested the outputs of l293d ic with leds. They work fine. But when I plug motors to the outputs they won’t work. Please help!

Krishan
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Krishan

Can you explain more about how to make the steering system

Krishan
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Krishan

Can I use two motors for fwd/rev?