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

EMBEDDED LIVE BATCH - 19 (ABINAYA MAAM) :

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

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. Here, the DC motor can be controlled by using L293 motor driver, where 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.

Expected Outcomes of the project :

A system on simulator to control a DC motor using PMW is implemented, the monitoring the running status of the DC motor using L293 motor driver allows the DC motor to drive on any direction and the running status ie, on which direction the DC motor is running is to be displayed on the LCD screen.

ANSWERS :

SIMULATION DIAGRAM :

The hardware selected for simulation are: ATmega 32, 2X16 LCD, DC motor, Resistor, L293 motor driver, voltage source and push buttons. Here, in simulation, motor supply current and the driver supply is not needed to be given to the driver pins.

MAIN PROGRAM :

/* Project_1_AVR.c
 * 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
 * Created: 30-03-2023 21:48:12
 * Author : arjun
 */ 

#include <avr/io.h> // Pre-processor directive for I/O registers
#define F_CPU 16000000l // CPU frequency
#include "avr/interrupt.h" // User defined pre-processor directive for interrupts
#include <util/delay.h> // Pre-processor directive for delay functions

#define sw_dir (PIND & (1<<1)) // D1 pin as push button for direction control
#define sw_spd (PIND & (1<<2)) // D2 pin as push button for speed control
#define pw (PINC & (1<<3)) // C3 pin as push button for power ON/OFF

#define lcd_port PORTB //	Port B pins used for LCD data
#define RS_high PORTD |= (1<<5) // D5 pin for Register select
#define RS_low PORTD &=~ (1<<5)
#define EN_high PORTD |= (1<<6) // D6 pin for Enable
#define EN_low PORTD &=~ (1<<6)
unsigned char i;

void  lcd_cmd(char cmd) // For command register
{
	lcd_port = (cmd & 0xF0); // For 4 bit LCD mode
	RS_low;
	EN_low;
	_delay_ms(1);
	EN_high;
	
	lcd_port = ((cmd<<4)&(0xF0));
	RS_low;
	EN_low;
	_delay_ms(1);
	EN_high;
}

void lcd_data(char data) // For data register
{
	lcd_port = (data & 0xF0); // For 4 bit LCD mode
	RS_high;
	EN_low;
	_delay_ms(1);
	EN_high;
	
	lcd_port = ((data<<4)&(0xF0));
	RS_high;
	EN_low;
	_delay_ms(1);
	EN_high;
}

void lcd_init()
{
	lcd_cmd(0x02); // Return cursor to 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 cursor
	_delay_ms(5);
	lcd_cmd(0x80); // Cursor to begin at the 1st line
	_delay_ms(5);
	lcd_cmd(0x28); // 4 bit LCD mode
	_delay_ms(5);
	
}

void cursor_position(char x, char y)
{
	if ((x<1||x>2)||(y>16||y<1))
	{
		x = 1;
		y = 1;
	}
	if (x == 1)
	{
		lcd_cmd(0x7F+y);
	}
	else
	{
		lcd_cmd(0xBF+y);
	}
}

void lcd_out(char x, char y, char *str)
{
	cursor_position(x, y);
	while (*str)
	{
		lcd_data(*str);
		str++;
	}
}

int main(void)
{
	DDRB = 0xFF; // Declaring pins B0 to B7 as outputs
	DDRA |= ((1<<0)|(1<<1)); // Declaring pins A0 and A1 as outputs
	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); // Internal pull up resistor for D2
	PORTC |= (1<<3); // Internal pull up resistor for C3
	
	i = 64; // As motor is running at with 25% duty cycle
	TCCR0 = 0x61; // Non-inverting mode, PWM phase correct with no pre-scalars
	GICR = (1<<INT0); // INT0 for interrupt
	MCUCR = 0x02; // Interrupt is negative edge triggered
	sei(); // Global interrupt
	lcd_init();
	
	while (1)
	{
		while (pw == 0) // Continues till the power push button gets released
		{
			if (sw_dir == 0) // if direction control push button gets released
			{
				PORTA = 0b00000001; // To rotate in clockwise direction
				lcd_out(1,1, "Motor is running");
				lcd_out(2,3, "clockwise");
			}
			else
			{
				PORTA = 0b00000010; // To rotate in anti clockwise direction
				lcd_out(1,1, "Motor is running");
				lcd_out(2,3, "anti clockwise");
			}
			
			OCR0 = i; // As i increases, the corresponding value is loaded into OCR0
		}
		PORTA = 0x00; // To stop the rotation
		lcd_out(1,1, "Motor is OFF");
		lcd_out(2,3, "CAUTION !!!");
	}
}

ISR(INT0_vect) // Interrupt service routine
{
	i = i + 20; // As i increases, the corresponding value is loaded into OCR0
}

OUTPUT :

• When motor is OFF :

• When motor is running clockwise :

• When motor is running anti clockwise :

RESULTS :

• A system on simulator to control a DC motor using PMW is implemented
• The monitoring of the running status of the DC motor using L293 motor driver which allows the DC motor to drive on any direction and the running status ie, on which direction the DC motor is running is displayed on the LCD screen.