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

AIM:

To 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.

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:

• 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:

• 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.

PROGRAM:

#include <avr/io.h>             // i/0 registers //
#include "avr/interrupt.h"      // external interrupt //
#define F_CPU 16000000ul        // CPU frequency //
#include <util/delay.h>         // delay function //
#define sw_dir (PIND & (1<<1))  // configuring d1 as switch for direction control //
#define sw_spd (PIND & (1<<2))  // configuring d2 as pushbutton for direction control //
#define pwr (PINC & (1<<3))     // configuring c3 as switch to power the motor //
#define lcd_port PORTB          // configuring port b for LCD //
#define RS_high PORTD |= (1<<6) // configuring d5 as register select //
#define RS_low PORTD &= ~(1<<6)
#define EN_high PORTD |= (1<<5) // configuring d6 as enable //
#define EN_low PORTD &= ~(1<<5)

unsigned char i;                // variable for changing the duty cycle //

void lcd_cmd (char cmd)         // command mode //
{
	lcd_port = (cmd & 0xf0);    // masking 4 bits 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)     // data mode //
{
	lcd_port = (data & 0xf0); // masking 4 bits 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);_delay_ms(5); // return 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 in 1st line //
	lcd_cmd(0x28);_delay_ms(5); // for 4 bit LCD mode //
}

void cursorpos(char x, char y)  // cursor position //
{
	if( (x < 1 || x > 2)  || (y < 1 || y > 16) )
	{
		x = 1;
		y = 1;
	}
	if(x == 1)
	lcd_cmd(0x7f + y);
	else
	lcd_cmd(0xBF + y);
}

void lcd_print(char row, char coloumn, unsigned int value, int digits)
{
	unsigned int temp;
	unsigned int unit;
	unsigned int tens;
	unsigned int hundred;
	unsigned int thousand;
	unsigned int million;
	
	unsigned char flag=0;
	
	if(row==0||coloumn==0)
	{
		cursorpos(1,1);
	}
	else
	{
		cursorpos(row,coloumn);
		
	}
	if(digits==5|| flag==1)
	{
		
		million=value/10000+48;
		lcd_data(million);
		flag=1;
	}
	if(digits==4 || flag==1)
	{
		
		temp = value/1000;
		thousand = temp%10 +48;
		lcd_data(thousand);
		flag=1;
	}
	if(digits==3 || flag==1)
	{
		
		temp = value/100;
		hundred = temp%10 +48;
		lcd_data(hundred);
		flag=1;
	}
	if(digits==2 || flag==1)
	{
		
		temp = value/10;
		tens= temp%10 +48;
		lcd_data(tens);
		flag=1;
	}
	if(digits==1 || flag==1)
	{
		
		unit = value%10 + 48;
		lcd_data(unit);
	}
	if(digits>5)
	{
		lcd_data('e');
	}
}


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

int main(void)
{
	DDRB = 0xFF;                 // configuring all 8 pins of port b as outputs //
	DDRA |= ((1<<0)|(1<<1));     // configuring a0 and a1 as outputs //
	DDRD &= ~(1<<1);             // configuring d1 as input //
	DDRD &= ~(1<<2);             // configuring d2 as input //
	DDRD |= (1<<5);              // configuring d5 as output //
	DDRD |= (1<<6);              // configuring d6 as output //
	DDRC &= ~(1<<3);             // configuring c3 as input //
	PORTD |= (1<<2);             // enabling internal pull up resistor for d2 //
	PORTC |= (1<<3);             // enabling internal pull up resistor for c3 //
	
	i = 64;
	
	TCCR0 = 0x61;				 // non-inverting mode, PWM phase correct mode with no prescalar //
	GICR = (1<<INT0);			 // using INT0 for interrupt //
	MCUCR = 0x02;				 // configuring interrupt negative edge triggered //
	sei();						 // enable global interrupt //
	
	lcd_init();					 // initialization //
	
	
	while (1)
	{
		while (pwr == 0)		 // while power switch remains closed //
		{
			if (sw_dir == 0)     // if direction control switch is open //
			{
				PORTA = 0b00000001; // 0, 1 to 1A and 2A to rotate the motor in clockwise //
				lcd_out(1,1, "Motor runs in ");
				lcd_out(2,2, "Clockwise");
			}
			
			
			OCR0 = i;               // as i increases in ISR, corresponding value is assigned to OCR0 //
			
		}
		while (sw_dir == 0)
		{
			if(sw_dir == 0)
			{
				PORTA = 0b00000010; // 1, 0 to 1A and 2A to rotate the motor in anti-clockwise //
				lcd_out(1,1, "Motor runs in ");
				lcd_out(2,2, "Anticlockwise");
			}
		}
		
		PORTA = 0x00;				// 0, 0 to 1A and 2A to stop the motor //
		lcd_out (1,1, "Motor is OFF         ");
		lcd_out (2,2, "              ");
	}
}
ISR(INT0_vect)						// interrupt service routine //
{
	i = i + 20;						// as i increases by 20 with each push, duty cycle value increases //
}

RESULT:

CASE 1:

The Motor is in OFF Condition.

CASE 2:

The Motor Runs in Clockwise Direction.

CASE 3:

The Motor Runs in Anticlockwise Direction.

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 to drive on any direction.
• Running status i.e. on which direction the DC motor is running is to be displayed on the LCD screen.