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

Components:

1. L293D Motor Driver IC: For driving the DC motor.
2. PWM (Pulse Width Modulation): To control the speed of the motor.
3. LCD Display: To display the running status of the motor.

Code:

#include <avr/io.h>

#include <util/delay.h>

#include <avr/interrupt.h>

#include "lcd.h" // Include your LCD library header file

#define MOTOR_FORWARD_PIN1 PD0

#define MOTOR_FORWARD_PIN2 PD1

#define MOTOR_PWM_PIN PD2

void pwm_init(void) {

// Set Timer0 to Fast PWM mode

TCCR0A = (1 << COM0A1) | (1 << WGM00) | (1 << WGM01); // Fast PWM, non-inverted

TCCR0B = (1 << CS00); // No prescaling

// Set PWM frequency

// TOP value for Fast PWM mode is 255

OCR0A = 128; // 50% duty cycle to start with

}

void motor_init(void) {

// Set MOTOR_FORWARD_PIN1, MOTOR_FORWARD_PIN2, and MOTOR_PWM_PIN as outputs

DDRD = (1 << MOTOR_FORWARD_PIN1) | (1 << MOTOR_FORWARD_PIN2) | (1 << MOTOR_PWM_PIN);

// Initial state (Motor stopped)

PORTD &= ~((1 << MOTOR_FORWARD_PIN1) | (1 << MOTOR_FORWARD_PIN2));

}

void lcd_init(void) {

// Initialize LCD (Assuming an initialization function from lcd.h)

lcd_init();

}

void lcd_display_status(const char *status) {

// Clear the LCD and display the status

lcd_clear();

lcd_set_cursor(0, 0);

lcd_print(status);

}

void set_motor_direction(int forward) {

if (forward) {

PORTD |= (1 << MOTOR_FORWARD_PIN1);

PORTD &= ~(1 << MOTOR_FORWARD_PIN2);

lcd_display_status("Motor Forward");

} else {

PORTD |= (1 << MOTOR_FORWARD_PIN2);

PORTD &= ~(1 << MOTOR_FORWARD_PIN1);

lcd_display_status("Motor Reverse");

}

}

void change_pwm_duty_cycle(uint8_t duty_cycle) {

OCR0A = duty_cycle;

}

int main(void) {

pwm_init();

motor_init();

lcd_init();

while (1) {

// Example: Set motor forward with 75% speed

set_motor_direction(1);

change_pwm_duty_cycle(191); // 75% duty cycle

_delay_ms(2000);

// Set motor reverse with 50% speed

set_motor_direction(0);

change_pwm_duty_cycle(128); // 50% duty cycle

_delay_ms(2000);

// Stop the motor

PORTD &= ~((1 << MOTOR_FORWARD_PIN1) | (1 << MOTOR_FORWARD_PIN2));

lcd_display_status("Motor Stopped");

_delay_ms(2000);

}

return 0;

}