Project 1 - Controlling a DC motor using PWM and monitoring its Running status
Overview of the Project:
Implement a system on the simulator for controlling a DC motor using L293 motor driver, monitor its status and print the running status of motor on the LCD Display.
Goals:
- Implement a system on simulator for Controlling the DC motor using L293 motor driver.
- Displaying the running status of DC motor on the LCD display.
Key Highlights of the Project:
- The DC motor can be controlled by using L293 motor driver.
- The speed of a DC motor can be controlled by varying its input voltage, for doing this is to use PWM (Pulse Width Modulation).
- L293D IC is a typical Motor Driver IC which allows the DC motor to drive on any direction.
Deliverables of this project:
- Implement the system for controlling DC motor.
- Controlling the speed of the DC motor using PMW.
- Displaying the present running status of DC machine on LCD display.
Expected Outcomes:
- Implement a system on simulator to control a DC motor using PMW
- Monitoring the running status of the DC motor using L293 motor driver which allows the DC motor to drive on any direction.
- Running status i.e. on which direction the DC motor is running is to be displayed on the LCD screen.
Circuit:

Code:
*
* GccApplication1.c
*
* Created: 07-11-2022 18:04:20
* Author : Kalicharan U
*/
#include <avr/io.h> // we are using i/o resisters of avr
#define F_CPU 16000000ul //define the crystal frequency
#include "avr/interrupt.h" // we are using external interrupt pin
#include <util/delay.h> //delay function purpose
#define sw_dir (PIND&(1<<1)) //D1 pin is declared as push button for direction control
#define sw_dspd (PIND&(1<<2)) //D2 pin is declared as push button for speed control
#define pw (PINC&(1<<3)) //c3 pin is declared as push button for power on/off.
#define lcd_port PORTB //portB pins are for LCD data
#define RS_high PORTD|=(1<<5) //D5 pin is used for resistor select(rs)
#define RS_low PORTD&=~(1<<5) //D5 pin is used for resistor select(rs)
#define EN_high PORTD|=(1<<6) //D6 pin is used for enable
#define EN_low PORTD&=~(1<<6) //D6 pin is used for enable
unsigned char var;
void lcd_cmd(char cmd) // command for LCD display
{
lcd_port=(cmd&0xf0); //Masking 4 bits for 4 bit LCD mode//
RS_low;
EN_low;
_delay_ms(1); //after 1ms disable LCD
EN_high; // enable the LCD
lcd_port=((cmd<<4)&(0xf0)); // LCD port
RS_low;
EN_low;
_delay_ms(1); //after 1ms disable LCD
EN_high; // enable the LCD
}
void lcd_data(char data) //send the data to LCD
{
lcd_port=(data &0xf0); //masking 4 bits for bit LCD mode//
RS_high; //access data register
EN_low;
_delay_ms(1);
EN_high;
lcd_port=((data<<4)&(0xf0)); //masking 4 bits for bit LCD mode//
RS_high; //access data register
EN_low;
_delay_ms(1);
EN_high;
}
void lcd_init()
{
lcd_cmd(0x38);
_delay_ms(5);
lcd_cmd(0x02);
_delay_ms(5); //return the cursor to home//
lcd_cmd(0x01);
_delay_ms(5); //clear screen //
lcd_cmd(0x0C);
_delay_ms(5); //display ON cursor OFF//
lcd_cmd(0x06);
_delay_ms(5); //increment cursor//
lcd_cmd(0x80);
_delay_ms(5); //force cursor to begin 1st line //
lcd_cmd(0x28); //force cursor to begin 2nd line //
_delay_ms(5);
}
void cursorpos(char x, char y)
{
if ((x<1||x>2)||(y>16)||(y<1)) //condition will check the rows and 16 columns
{
x=1; //x=rows
y=1; //y=columns
}
if (x==1)
{
lcd_cmd(0x7F+y);
}
else
{
lcd_cmd(0xBF+y);
}
}
void lcd_out(char x,char y,char *str)
{
cursorpos(x,y);
while (*str)
{
lcd_data(*str);
str++;
}
}
int adc_read(char channel)
{
unsigned int a, result;
ADMUX=channel; //here we are going to use which channel we need to select in mux here using 2 bit
ADCSRA=0X80; // control and status register to enable the adc conversion enable the interrupt flag adc interrupt ADEN=1
ADCH=0x00; // showing the value 0 or clearing the adc register
ADCL=0x00; //showing the value 0
ADCSRA|=(1<<6); // to start the conversion 6 bit adsc high
while((ADCSRA&0x40)!=0); // when the conversion become zero means conversion of adc (0x40means interrupt pin)
a=ADCL; //dummy data type a and ais stored the adcl register (ADC0-ADC7)
result=ADCH; //store the high value (ADC8-ADC9)
result=result<<8; //to get proper result or aligned value we need to do left shift
result=result|a; //we are adding the ADCL+ADCH to get 16 bits
return result;
}
int main(void)
{
DDRB=0xFF; // declaring all 8 pins as output
DDRA|=((1<<0)|(1<<1)); // declaring A0 and A1 as output
DDRD&=~(1<<1); //declaring D1 pin as input
DDRD&=~(1<<2); //declaring D2 pin as input
DDRD|=(1<<5); //declaring D5 pin as output
DDRD|=(1<<6); //declaring D6 pin as output
DDRC&=~(1<<3); //declaring C3 pin as input
PORTD|=(1<<2); //enabling internal pull up resistor for D2
PORTC|=(1<<3); //enabling internal pull up resistor for D3
var=64; // initializing var=64 because we are running the motor with 25%duty cycle
TCCR0=0X61; // non inverting mode, PWM phase correct mode, no pre scalar
GICR=(1<<INT0); // using into for interrupt
MCUCR=0X02; // make interrupt negative edge triggered
sei(); //enable global interrupt
lcd_init(); // initialized LCD
while (1)
{
while(pw==0) //continue till push button is released
{
if (sw_dir==0) // if the direction control push button is released
{
PORTA=0b00000001; //10 respective 1A 2A pins to rotate in clockwise direction
lcd_out(1,1,"Motor Running");
lcd_out(2,4,"Clockwise") ; // running clockwise direction
}
else
{
PORTA=0b00000010; //10 respective 1A 2A pins to rotate in anti-clockwise direction
lcd_out(1,1,"Motor Running");
lcd_out(2,4,"AntiClockwise") ; // running anti-clockwise direction
}
OCR0=var; // var increase in ISR, the corresponding value is to be loaded into OCR0
}
PORTA=0X00; //0 0 to respective 1A 2A pins to stop condition
lcd_out(1,1,"Motor is OFF");
}
}
ISR(INT0_vect) // interrupt service routine
{
var=var+10; //var increases by 10 in each push and the corresponding value is to be loaded into OCR0 in while loop
}
Screenshot-1:When Motor Power button(Open) is in OFF condition

Screenshot-2:When Motor Power button(Closed) is in ON condition,Direction control is in clockwise direction

Screenshot-3:When Motor Power button(Closed) is in ON condition,Direction control is in Anticlockwise direction

Screenshot-4:When Motor Power button(Closed) is in ON condition,Speed control button pressed.
