Question

Draw a breadboard fritzing diagram that connects a HT12D decoder, 433 MHz Receiver, L2930 Motor Driver and 2 DC motors that allows for bidirectional proportional motor control.

Answer 1

Explanation of above ckt

Material required :

• 433 MHz RF transmitter and receiver
• HT12D decoder
• HT12E encoder
• push buttons
• two 9volts motors
• 1M ohms,47k ohms and 470 ohm resistor
• 7805 voltage regulator
• 9volt battery
• bread board
• connecting wires

Transmitter module

It consists of 3 pins namely vcc ,Din and ground

The Vcc pin has wide range input voltage from 3v to 12v

It consumes a minimum current of 9mA and con go as high as 40mA during transmission.

It modulate signal using ASK modulation and sent on air at a frequency of 433MHz. The speed at which it transmit data is around 10Kbps.

Receiver module

It has 4 pins namely Vcc, Dout, linear out and Ground

The pins should be powered with a regulated 5v supply. The operating current of this module is less than 5.5mA.

The pins Dout and linear out is shorted together to receive the 433MHz signal from air. This signal is then demodulated to get the data and is sent out through the data pin.

Decoders

The HT12D and HT12E are 4 data bit decoder and encoder modules. This means that we can make 16 different combinations of inputs and outputs. These are 18 pins IC which can operate between 3v to 12v input power supply. As said they have 4 data bit and 8 address bits, these bits are set same on both the encoder and decoder to make them work as a pair.

L293D description

It is a typical motor driver IC which allows DC motor to drive on either direction.It is a 16 pin IC which can control a set of two DC motors simultaneously in any direction. It means that we can control two DC motors with single L293D.

L293D logic table

• pin 2 = logic 1 and pin 7 = logic 0 ---> clockwise direction
• pin 2 = logic 0 and pin 7 = logic 1 ---> anticlockwise direction
• pin 2 = logic 0 and pin 7 = logic 0 ---> no rotation
• pin 2 = logic 1 and pin 7 = logic 1 ---> no rotation

now this is same for other motor2 in figure.