RF controlled robotic vehicle
In this modern era, all people know about robots. Robots are machines which reduces the human efforts in heavy works in industries and many other domains and makes life easy. In this blog, what is RF controlled robotic vehicles and how it works is explained clearly. This RF controlled robotic vehicle, Microcontroller is not required for operating this robot, it makes use of Radio Frequency(RF) decoder and motor driver.
It is controlled using 4 push button at the transmitter side. The transmitter also contains RF transmitter and RF encoder. Transmitter feeds the command to the robot so it can perform the respective task.
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L293D MOTOR DRIVER
It is a IC motor driver, containing of two channels for driving the motors. It consists of a separate power supply pin which is used for the external supply. For the amplification of current, it consists of two inbuild transistor darlington pair.
RF Transmitter and Receiver:
In this robotic vehicle, Transmitter and receiver works at a frequency of 433MHz. The device contains a crystal stabilized oscillator to ensure accurate frequency for longer range. One antenna is fixed externally for this module.
With this effective features long range RF communication is performed. It does not send data using UART communication of PC or microcontroller because there is lots of noise at this frequency. Encoder and decoder ICs are used to extract data from the external noise.
The maximum transmitter range is upto 100 meters at a maximum supply voltage. For example, for 5V supply, the range of transmitter varies by 50-60 meter with the help of 17cm length antenna.
Features:
RF Transmitter
Frequency Range: 433 MHz
Output Power: 4-16dBm
Input supply: 3 to 12 volt dc
RF Receiver
Frequency : 1MHz
Low Power Consumption
Supply voltage: 5 volt
Circuit-diagram and explanation
From transmitter side- data encoder and an RF transmitter is used. The four push buttons is linked with the encoder with respect to ground. When any button is pressed, encoder will get a digital LOW signal and then this signal applied serially to RF transmitter. The Encoder IC HT12E encodes data or signal and converting it into serial form and then transmits this signal by using RF transmitter into the surroundings.
At the receiver end there is a RF receiver to receive data or signal and then feed to HT12D decoder. This decoder IC converts the received serial data to parallel and then send these decoded signal to L293D Motor driver IC. According to the received signal robot operates by using 2 DC motor in all the desired directions.
WORKING OF RF CONTROLLED ROBOT:
It works according to the button pressed at the transmitter.
PUSH BUTTON CONTROLLER:
| Button Pressed | Robot directions |
| First (1) | Left |
| Second (2) | Right |
| First and Second (1 & 2) | Forward |
| Third and Fourth (3 & 4) | Backward |
| No Button Pressed | Stop |
Applications :
~It is used in defense sector.
~It is used in the construction site.
~In industries, it is used to control trolley and lift.
