L293d is an H Bridge bidirectional motor driver IC used to interface DC motor and stepper motors to Microcontrollers.
CircuitsGallery.com already discussed about the working principle of L293 IC with an example of bidirectional motor driver circuit.It is very easy to make a DC motor control using microcontroller. In this article I’m gonna show you the interfacing of DC motor with PIC16F877A microcontroller using L293D motor driver with the help of Mikro C coding and Proteus 8 simulation. Basically it is a bidirectional motor driver circuit with PIC MCU.This is the most common circuit in robotics engineering. I’m sure this article will be helpful for PIC MCU beginners.
H bridges are widely discussed topic in electronics. As we know, just changing the polarity of supply voltage causes rotating of DC motor in reverse direction.
But this method is not suitable for practical circuit. So, how to run DC motor in clockwise and anti-clockwise direction without changing the supply polarity?
Here comes the importance of H Bridge. In a typical H Bridge circuit two pairs of transistors are connected in a bridge fashion and the motor is driven through the collector terminal.
Obviously we know that ICs make life easy!
- The transistor based H bridges are little complex and bulky and also time consuming while implementing practically.
- L293 is basically an H bridge IC capable of driving two motors simultaneously, that means it has two embedded H bridges inside!
Interfacing of L293 to DC motor and microcontroller is very easy and simple process.
The specialty of L293 is that it has dedicated ‘Enable Pin’ to control the motor. By manipulating this pin it is possible to control the speed of dc motor with Pulse Width Modulation technology.