Project 1 - Controlling a DC motor using PWM and monitoring its Running status
Program
#include
#define F_CPU 16000000ul //define the crystal frequency
#include “avr/interrupt.h” // we are using external interrupt pin
#include
#define sw_dir (PIND&(1<<1>#define sw_dspd (PIND&(1<<2>#define pw (PINC&(1<<3>#define lcd_port PORTB //portB pins are for LCD data
#define RS_high PORTD|=(1<<5>#define RS_low PORTD&=~(1<<5>#define EN_high PORTD|=(1<<6>#define EN_low PORTD&=~(1<<6>unsigned char i;
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>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>RS_high; //access data register
EN_low;
_delay_ms(1);
EN_high;
}
void lcd_init()
{
lcd_cmd(0x28);
_delay_ms(5); //used for 4 bits LCD mode //
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>2)||(y>16)||(y<1>{
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); //{0C-1=0B} for starting the second 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 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>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>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>DDRD&=~(1<<1>DDRD&=~(1<<2>DDRD|=(1<<5>DDRD|=(1<<6>DDRC&=~(1<<3>PORTD|=(1<<2>PORTC|=(1<<3>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<
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 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
}
Output
Power Switch: OFF, Direction Switch: OFF, Speed Switch: OFF :: Motor is TURN OFF Condition
Power Switch: ON, Direction Switch: OFF, Speed Switch: OFF :: Motor is TURN ON Condition
Power Switch: ON, Direction Switch: ON, Speed Switch: OFF :: Motor is TURN ON and Direction of Rotation: REVERSE
Power Switch: ON, Direction Switch: OFF, Speed Switch: ON :: Motor is TURN ON and Speed of Motor: INCREASED