1. EMBEDDED SYSTEMS TUTORIAL11 - CONTROLLING DC
MOTORS WITH AVR
Hi…friends , welcome back..! I am again here with some embedded systems stuff , this time we will learn
how to control motor using AVR MCUs. Motors are very important for almost every ROBOTICS projects
and other electronics projects as well ,and using microcontroller with motors makes is very easy. So lets
have a look , how it happens..??
Introduction
As we know we can generate different output signal from our MCU, which are used to drive the motors
but the signal generated by the MCU is not strong enough to drive the motor , so we need something else
to drive the motor as per the instruction of MCU, and this something else is a motor drive , there are many
motor drivers available , like ULN200X family ICs , L293D and L298 etc. here we are going to
use L293D. I will suggest you to go through my article
Before reading this article as I have discussed almost everything in that article about L293D. ROBOTICS
TUTORIAL 1- HOW TO USE L293D MOTOR DRIVER IC
Now we are pretty much clear about our task, we have to drive a simple DC motor using AVR MCU and
L293D motor driver.
Connections
So first of we have to prepare connections . just implement this simple circuit for that. Things we are going
to need are2 MOTORs
L293D IC
ATmega 16
And some connecting wire and power supply.

2. Source code
Here is sample code. The code is written to rotate two motors in clockwise direction for some time ,then to
stop one motor and rotate other one in clockwise direction for some time and again rotate second motor
in clockwise direction and stop first one for some time ,then to rotate one motor in clockwise direction
and other one in anticlockwise direction and finally stop both the motor. Code is self explanatory still if you
are facing any problem just let me know..:)
/*
* DRIVING_MOTOR_WITH_AVR.c
*
* Created: 2/2/2013 10:04:53 PM
* Author: ABHILASH
*/
#include <avr/io.h>
#include <util/delay.h>
void main()
{
DDRC=0b00001111; //declaring pin 0-3 of PORTC as output pins
while(1)
{
PORTC=0b00000101; // both motor in clockwise direction
_delay_ms(3000); // delay for some time

3. PORTC=0b00000001; // only one motor rotating in clockwise direction
_delay_ms(3000); // delay for sometime
PORTC=0b00000100; // second motor rotating in clockwise direction
_delay_ms(3000); // delay for some time
PORTC=0b00001001; // one motor in clockwise direction other one in anticlockwise
_delay_ms(3000); // delay for some time
PORTC=0b00000000; // stop
_delay_ms(3000); // delay for some time
}
}
That all now burn your microcontroller with this program and power up the circuit and you will things going
on..and you can see how easy is it to control a motor with AVR MCU.
DOWNLOADS
You can download source code , .hex file and proteus design file hereSOURCE CODE .c FILE
.hex FILE OF PROGRAM
PROTEUS DESIGN FOR PROJECT