Project 1 - Controlling a DC motor using PWM and monitoring its Running status

code

#include <avr/io.h> // we are using i/o resisters of avr
#define F_CPU 16000000L //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)
#define EN_high PORTD |= (1<<6) //d6 pin is used for enable
#define EN_low PORTD &=~ (1<<6)
unsigned char i;

void lcd_cmd(char cmd) // command for LCD display
{
lcd_port = (cmd & 0xf0);
RS_low;
EN_low;
_delay_ms(1); //after 1ms disable LCD
EN_high;
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);
RS_high; //access data register
EN_low;
_delay_ms(1);
EN_high;
lcd_port = ((data<<4) & (0xf0));
RS_high; //access data register
EN_low;
_delay_ms(1);
EN_high;
}

void lcd_init()
{
lcd_cmd(0x28); //used for 4 bits LCD mode //
_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 //
}

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); //{80-1=0B}for starting the first list hex decimal value(80){y we are the 7F+y means we need to start from that column
}
else //(x==2)
{

lcd_cmd(0xBF + y);
}
}

void lcd_out(char x, char y, char *str) //here we are checking which position we want to print
{
cursorpos(x,y);
while(*str)
{
lcd_data(*str);
str++;
}
}

int adc_read(char channel) // we are configuring the adc value
{
unsigned int a, result;
ADMUX = channel; //here we are going to use which channel we need to select in mux
ADCSRA = 0X80; // control and status register to enable the adc conversion enable the interrupt flag adc interrupt ADEN=1
ADCH = 0X00;
ADCL = 0x00;
ADCSRA |= (1<<6);
while((ADCSRA & 0x40) != 0); // when the conversion become zero means conversion of adc (0x40means interrupt pin)
a= ADCL; // data type a and a is stored the adcl register (ADC0-ADC7)
result = ADCH; //store the high value (ADC8-ADC9)
result = result<<8;
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
i=64; // initializing i=64
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();

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;
lcd_out(1,1,"Motor ON- CL "); // running clockwise direction

}
else
{
PORTA = 0b00000010;
lcd_out(1,1,"Motor ON- ACL"); // running anti-clockwise direction

}
OCR0 = i; // i 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 TURNOFF");
}
}
ISR(INT0_vect) // interrupt service routine
{
i=i+20; //as i increases the duty cycle also increases

}

output

anticlock

Increasing speed

POWER ON

POWER OFF