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

#include //we are using I/O registers of AVR

 #define F_CPU 16000000L // define the crystal frequency

 #include "avr/interrupt.h" // we are using external interrupt pin

 #include // delay function purpose

 #define sw_dir (PIND & (1<<1)) // d1 pin is declared as switch 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 is declared as switch 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 Register Select(RS)

 #define RS_low PORTD &=~ (1<<5) // d5 pin is used for RS

 #define EN_high PORTD |= (1<<6) // d6 pin is used for Enable

 #define EN_low PORTD &=~ (1<<6) // d6 pin is used for En.

 unsigned char i;

 

 void lcd_cmd(char cmd) //command for lcd display

 {

lcd_port = (cmd & 0xf0); //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); //4 bits for 4 bit lcd mode

RS_high; //access data register

EN_low;

_delay_ms(1);

EN_high;

lcd_port = ((data<<4) & (0xf0)); //4 bits for 4 bit lcd mode

RS_high; //access data register

EN_low;

_delay_ms(1);

EN_high;

 }

 

 void lcd_init()

 {

lcd_cmd(0x28);// used for 4 bit lcd mode

 lcd_cmd(0x28);// used for 4 bit lcd mode

_delay_ms(5);

lcd_cmd(0x02); // return home

_delay_ms(5);

lcd_cmd(0x01); // clear screen

_delay_ms(5);

lcd_cmd(0x0C); // display on cursor off

_delay_ms(5);

lcd_cmd(0x06); // increment the display cursor

_delay_ms(5);

lcd_cmd(0x80); // force cursor to begin from 1st line

_delay_ms(5);

 }

 

 void cursorpos(char x,char y)

 {

if((x<1 || x>2) || (y>16 || y<1 )) //condition will checks the 2 rows and 16 columns

{

x=1; //x= row

y=1; //y= column

}

if(x==1)

{

lcd_cmd(0x7F + y); //{ 80-1 = 7F} for starting the 1st line hex decimal value (80) {y we r using the 7F+y means we need to dtart from                                            that column}

}

else //(x==2)

 {

 

lcd_cmd(0xBF + y); //{0C-1 = 0B} for starting the 2nd line, 2nd row.

}

 }

 

 

 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 main(void)

 {

DDRB = 0XFF; //Declaring all 8-pins as output.

DDRA |= ((1<<0)| (1<<1)); //Declaring A0 & A1 pins 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 because we are running the motor with 25% duty cycle.

TCCR0=0X61; //Non-Inverting mode, PWM phase correct mode,NO prescalar.

GICR=(1<

MCUCR=0X02; //make interrupt negative edge triggered

sei(); //Enable global interrupt

lcd_init(); //Initialize lcd

 

while (1)

{

while(pw==0)  //if switch is off

{

if(sw_dir == 0)  //if switch is off

{

PORTA = 0b00000001; // 1 0 to respective 1A 2A pins to rotate in clockwise direction.

lcd_out(1,1,"Motor Clock-wise "); //Running clock wise direction

 }

else

{

PORTA = 0b00000010; // 1 0 to respective 1A 2A pins to rotate in Anti-Clockwise direction.

lcd_out(1,1,"Anti clock-wise ");

 

}

OCR0 = i; //i increases in ISR, the corresponding value is to be loaded into OCR0.

 

}

 

PORTA = 0x00; // 0 0 to respective 1A 2A pins to Stop rotation.

lcd_out(1,1,"Motor is TURNOFF");

}

 }

 ISR(INT0_vect) //interrupt service routine

 {

i=i+20; // as i increases the duty cycle also increases. i increases by 20 in each push//

// and the corresponding value is to be loaded into OCR0 in while loop//

 }