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

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

1. Overview of the Project:

• Implement a system on the simulator for controlling a DC motor using L293 motor driver, monitor its status and print the running status of motor on the LCD Display.

2. Goals:

• Implement a system on simulator for Controlling the DC motor using L293 motor driver.
• Displaying the running status of DC motor on the LCD display.
• Key Highlights of the Project:

3. The DC motor can be controlled by using L293 motor driver.

• The speed of a DC motor can be controlled by varying its input voltage, for doing this is to use PWM (Pulse Width Modulation).
• L293D IC is a typical Motor Driver IC which allows the DC motor to drive on any direction.
• Deliverables of this project:

4. Implement the system for controlling DC motor.

• Controlling the speed of the DC motor using PMW.
• Displaying the present running status of DC machine on LCD display.

5. Expected Outcomes:

• Implement a system on simulator to control a DC motor using PMW
• Monitoring the running status of the DC motor using L293 motor driver which allows the DC motor todrive on any direction.
• Running status i.e. on which direction the DC motor is running is to be displayed on the LCD screen.

Title: Controlling a DC Motor with L293 Motor Driver and Monitoring its Running Status

Aim:

The aim of this project is to implement a system on the simulator to control a DC motor using PWM with the L293 motor driver. The project also involves monitoring the running status of the DC motor and displaying it on an LCD screen.

Components Used:

1. AVR microcontroller (ATmega32)
2. L293 motor driver IC
3. DC motor
4. Push button switch
5. LCD display (16x2)
6. 5V power supply
7. Resisters

Circuit Diagram:

Code:

#include <avr/io.h>

#define F_CPU 16000000L

#include "avr/interrupt.h"

#include <util/delay.h>

#define sw_dir (PIND & (1<<1))

#define pw (PINC & (1<<3))

// LCD connections and commands

#define lcd_port PORTB

#define RS_high PORTD |= (1<<5)

#define RS_low PORTD &=~ (1<<5)

#define EN_high PORTD |= (1<<6)

#define EN_low PORTD &=~ (1<<6)

// LCD specific commands

#define LCD_LINE_1 0x80

#define LCD_LINE_2 0xC0

// Variable to store duty cycle

unsigned char i;

// Function to send a command to the LCD

void lcd_cmd(char cmd)

{

lcd_port = (cmd & 0xF0); // Send higher 4 bits of the command

RS_low; // Set RS pin low (command mode)

EN_low; // Set EN pin low

_delay_ms(1); // Delay to ensure command is processed

EN_high; // Set EN pin high to process the command

lcd_port = ((cmd << 4) & 0xF0); // Send lower 4 bits of the command

RS_low; // Set RS pin low

EN_low; // Set EN pin low

_delay_ms(1); // Delay to ensure command is processed

EN_high; // Set EN pin high to process the command

}

// Function to send data to the LCD

void lcd_data(char data)

{

lcd_port = (data & 0xF0); // Send higher 4 bits of the data

RS_high; // Set RS pin high (data mode)

EN_low; // Set EN pin low

_delay_ms(1); // Delay to ensure data is processed

EN_high; // Set EN pin high to process the data

lcd_port = ((data << 4) & 0xF0); // Send lower 4 bits of the data

RS_high; // Set RS pin high (data mode)

EN_low; // Set EN pin low

_delay_ms(1); // Delay to ensure data is processed

EN_high; // Set EN pin high to process the data

}

// Function to initialize the LCD

void lcd_init()

{

// Initialize LCD in 4-bit mode with 2 lines and 5x8 font size

lcd_cmd(0x28);

_delay_ms(5);

lcd_cmd(0x02); // Return cursor to home position

_delay_ms(5);

lcd_cmd(0x01); // Clear display

_delay_ms(5);

lcd_cmd(0x0C); // Display ON, cursor OFF

_delay_ms(5);

}

// Function to display a string on the LCD

void lcd_string(const char* str)

{

while (*str)

{

// Send each character of the string to the LCD

lcd_data(*str++);

}

}

// Function to configure the adc value

int adc_read(char channel)

{

unsigned int a, result;

ADMUX = channel; // Select ADC channel

ADCSRA = 0X80; // Enable ADC, Start conversion, Enable ADC interrupt

ADCH = 0X00; // Clear ADC high value

ADCL = 0x00; // Clear ADC low value

ADCSRA |= (1<<6); // Start the conversion

// Wait for the conversion to complete

while((ADCSRA & 0x40) != 0);

a= ADCL; // Read ADC low value

result = ADCH; // Read ADC high value

result = result<<8; // Read ADC high value

// Combine high and low values to get the result

result = result | a ;

return result;

}

//main function

int main(void)

{

// Set data direction for LCD and control pins

DDRB = 0xFF; // All 8 pins of PORTB are set as output

DDRA |= ((1 << 0) | (1 << 1)); // A0 & A1 pins set as output

DDRD &= ~(1 << 1); // D1 pin set as input

DDRD &= ~(1 << 2); // D2 pin set as input

DDRD |= (1 << 5); // D5 pin set as output

DDRD |= (1 << 6); // D6 pin set as output

DDRC &= ~(1 << 3); // C3 pin set as input

PORTD |= (1 << 2); // Enable internal pull-up resistor for D2

PORTC |= (1 << 3); // Enable internal pull-up resistor for D3

i = 64; // Initialize i=64 for 25% duty cycle

TCCR0 = 0x61; //Non-Inverting mode, PWM phase correct mode

GICR = (1 << INT0); // Enable external interrupt INT0

MCUCR = 0x02; // Set interrupt INT0 to be triggered on falling edge

sei(); // Enable global interrupt

lcd_init();

while (1)

{

while (pw == 0)

{

// Continue till the push button is released

if (sw_dir == 0)

{

// Set appropriate motor direction pins

PORTA = 0b00000001;

lcd_cmd(LCD_LINE_1);

lcd_string("->Motor ON-CL "); // Display message

}

else

{

// Set appropriate motor direction pins

PORTA = 0b00000010;

lcd_cmd(LCD_LINE_1);

lcd_string("->Motor ON-ACL "); // Display message

}

OCR0 = i;

}

PORTA = 0x00; // Turn off motor

lcd_cmd(LCD_LINE_1);

lcd_string("->Motor TURN OFF "); // Display message on LCD

}

}

ISR(INT0_vect)

{

// Increase duty cycle when the external interrupt occurs

i = i + 22;

}

Code Explanation:

The code starts by including necessary libraries and defining constants for the pins and commands used in the program. It then initializes the ADC and sets up the LCD display. The main function configures the ports and pins for motor control, external interrupt, and ADC.

The main loop continuously monitors the push button state and the direction switch. When the push button is pressed, the motor starts running in the specified direction, and the duty cycle is adjusted based on the external interrupt.

When the push button is released, the motor stops, and the LCD displays the status accordingly.

Explanation of Registers Used in the Program:

1. DDRB, DDRA, DDRD, DDRC: Data Direction Registers for configuring the direction of PORTB, PORTA, PORTD, and PORTC pins.
2. PORTD: Used for enabling internal pull-up resistors for D2 and D3 pins (push button and direction switch inputs).
3. TCCR0: Timer/Counter Control Register for Timer0 configuration (PWM settings).
4. GICR: General Interrupt Control Register for enabling external interrupts.
5. MCUCR: MCU Control Register for configuring external interrupt behavior (trigger on falling edge).
6. ADCSRA, ADMUX: ADC Control and Status Registers for configuring and starting ADC conversion.

Output with All Possible Conditions:

1. When the push button is pressed and the direction switch is in one position, the motor starts running in the specified direction with a duty cycle proportional to the external interrupt count. The LCD displays the running status.

CLOCKWISE:

2. When the push button is pressed and the direction switch is in the other position, the motor starts running in the opposite direction with a duty cycle proportional to the external interrupt count. The LCD displays the running status.

ANTI CLOCKWISE:

3. When the push button is released, the motor stops, and the LCD displays the "Motor TURN OFF" message.

Result:

The implemented system successfully controls the DC motor using PWM and the L293 motor driver. The motor can be started, stopped, and its speed can be adjusted using the push button and direction switch. The running status of the motor (clockwise or anti-clockwise) is displayed on the LCD.

Conclusion:

The project successfully demonstrates the control of a DC motor using PWM and the L293 motor driver. The system allows the user to start and stop the motor, adjust its speed, and monitor its running status. This project can be useful for various applications that involve motor control and monitoring.

For verification purposes here I have attached the execution video link to access: https://drive.google.com/file/d/1Fx0WJaOe3cckaFBvl52XRkn6S3p8UXYs/view?usp=sharing

For all project files link to access: https://drive.google.com/drive/folders/1G6jU8BRNTHHw1VddxjpcVg5gSYaCW_Mx?usp=sharing