Drive your robot DC motors with an H-Bridge

This post forms part of my Line Following Robot project and will serve as my research for how to accurately control the speed and direction of the line follower.

What is an h-bridge?
This circuit is called an h-bridge because of it's construction - notice the capital H formed by the diode connections in the center of the diagram below (Thank you to Circuits Today for the diagram).  As you can see the elements used to drive the motor are two NPN and two PNP transistors, four diodes and four 1K ohm resistors.  To read more about the specifics of this circuit and its workings, click on the "Circuits Today" link above.  This was just some background info.

H-bridge circuit diagram

As you can see from the table above, by using the digital outputs on a microcontroller, the speed and direction of the motor can be controlled by switching the outputs to digital zero (0V) or to digital 1 (5V). on A, B, C or D respectively.

H-bridge package from Pololu
DRV8833 dual motor driver carrier, bottom view with dimensions
DRV8833 dual motor driver carrier, 
bottom view with dimensions
I considering using a "dual motor driver carrier" (DRV8833) package from +Pololu Robotics and Electronics which is available through Micro Robotics in Centurion, Pretoria for R145.00.  Click on DATASHEET to view it.

This motor driver breakout board operates on 2.7 - 10.8Vdc and produces a continuous current of 1.2A per channel (peak 2A).

Below is an image of the minimum wiring required for using this driver carrier with a microcontroller:
Minimal wiring diagram for connecting a microcontroller to a DRV8833 dual motor driver carrier.
Minimal wiring diagram for connecting a microcontroller to a DRV8833 dual motor driver carrier.
From this image it should be simple to produce the code needed to drive the motors and I will share the code in the final post of my line follower project.
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