Project 1 - Controlling a DC motor using PWM and monitoring its Running status
/*
* AVR project 1.c
*
* Created: 12/19/2024 9:13:40 PM
* Author : yuvar
*/
#include <avr/io.h>
#define F_CPU 16000000
#include <util/delay.h>
#include <avr/interrupt.h>
#define lcdport PORTB
#define en_high PORTD|=(1<<6)
#define en_low PORTD &=~(1<<6)
#define rs_high PORTD|=(1<<5)
#define rs_low PORTD &=~(1<<5)
#define motor_dir (PIND&(1<<1))
#define motor_spd (PIND& (1<<2))
#define pwr (PINC&(1<<3))
unsigned char i;
void lcd_command(unsigned char cmd);
void lcd_data(unsigned char data);
void lcd_init();
void cursorpos(char x, char y);
void lcd_out(char x, char y, char *str);
int adc_read(char channel);
void lcd_command(unsigned char cmd)
{
lcdport = (cmd&0xf0);
rs_low;
en_low;
_delay_ms(1);
en_high;
lcdport=((cmd<<4)&(0xf0)); // LCD port
rs_low;
en_low;
_delay_ms(1); //after 1ms disable LCD
en_high; // enable the LCD
}
void lcd_data(unsigned char data)
{
lcdport =(data&0xf0);
rs_high;
en_low;
_delay_ms(1);
en_high;
lcdport=((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_command(0x28);_delay_ms(5);
lcd_command(0x02);_delay_ms(5);
lcd_command(0x01);_delay_ms(5);
lcd_command(0x0C);_delay_ms(5);
lcd_command(0x06);_delay_ms(5);
lcd_command(0x80);_delay_ms(5);
}
void cursorpos(char x,char y)
{
if( (x < 1 || x > 2) || (y < 1 || y > 16) )
{
x = 1;
y = 1;
}
if(x == 1)
lcd_command(0x80+y);
else
lcd_command(0xC0+y);
}
void lcd_out(char x,char y,char *str)
{
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 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 a is 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
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 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(pwr==0) //continue till push button is released
{
if (motor_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 ON-CLW"); // running clockwise direction
}
else
{
PORTA=0b00000010; //10 respective 1A 2A pins to rotate in anti-clockwise direction
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_OFF");
}
}
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
}