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

Aim : Controlling a DC motor using PWM and Monitoring Its Running Status.

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.

Code -

#include <avr/io.h>           //using I/O of avr
#define F_CPU 1600000UL        //define CPU/crystal frequency
#include <util/delay.h>      //used for delay 
#include <avr/interrupt.h>    //using for external interrupt
#define sw_dir (PIND &(1<<1))    //declared as switch for direction control
#define sw_dspd (PIND &(1<<2))   // declare as switch for speed control
#define pw (PINC &(1<<3))         // port c pin 3 as ON OFF button

#define lcd_port PORTB    
#define RS_high PORTD |=(1<<5)   //D5 for resister select
#define RS_low PORTD &=~ (1<<5)
#define EN_high PORTD |=(1<<6)      //D6 for enabling 
#define EN_low PORTD &=~ (1<<6)
unsigned char i;


void lcd_cmd(char cmd)
{
	lcd_port=(cmd & 0xf0);  //4 bit LCD mode 
	RS_low;
	EN_low;
	_delay_ms (100);  //after 1ms disable LCD
	EN_high;
	lcd_port=((cmd<<4) & (0xf0));
	RS_low;
	EN_low;
	_delay_ms (100);
	EN_high;
}


void lcd_data (char data) //send data for display 
{
	lcd_port=(data & 0xf0);
	RS_high;
	EN_low;
	_delay_ms (100);
	EN_high;
	lcd_port=((data<<4) & (0xf0));
	RS_high;   // acces the data resister
	EN_low;
	_delay_ms (100);
	EN_high;
}


void lcd_init()
{
	lcd_cmd(0x02); _delay_ms(500);
	lcd_cmd(0x01); _delay_ms(500);
	lcd_cmd(0x0C); _delay_ms(500);
	lcd_cmd(0x06); _delay_ms(500);
	lcd_cmd(0x80); _delay_ms(500);
	lcd_cmd(0x28); _delay_ms(500);
}


void cursorpos (char x, char y)
{
	if ((x<1 || x>2) || (y>16) || (y<1))  //check 2rows and 16 columns
	{
		x=1;
		y=1;
	}
	if(x==1)
	{
		lcd_cmd(0x7f+y); //starting 1st line with hexa decimal values 
	}
	
	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)  //command for row and column
	{
		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 adc_read(char channel)
{
	unsigned int result,a;
	ADMUX=channel;
	ADCSRA=0x80;  //control status resister to enable the adc conversion
	ADCH=0X00;
	ADCL=0X00;
	ADCSRA|=(1<<6);
	while ((ADCSRA & 0X40)!=0);
	a=ADCL;
	result=ADCH;  //store higher values 
	result=result<<8;
	result=result|a;
	return result;
}





int main(void)
{
	DDRB=(0xFF);               // PORTB as output port
	DDRA |= ((1<<0) || (1<<1)); //A0 & A1 as output 
	DDRD&=~(1<<1);
	DDRD&=~(1<<2);
	DDRD|=(1<<5);
	DDRD|=(1<<6);
	DDRC&=~(1<<3);
	PORTD=(1<<2);
	PORTC|=(1<<3);
	i=64;
	TCCR0=0x61;  // non inverting & PWM phase correction mode 
	GICR=(1<<INT0); 
	MCUCR=0x02;  //interrupt with negative edge trigger 
	sei();
	lcd_init();  //initialized LCD
	
	while (1)
	{
		while(pw==0)  //continue till button is Closed 
		{
			if (sw_dir==0)    
			{
				PORTA|= (1<<0); //0b00000001;  // 0 1 to 1A and 2A pins to rotate motor clockwise 
				lcd_out(1,1,"Motor is Running");
				lcd_out(2,1,"Clockwise");
			}
			else
			{
				PORTA|=(1<<1); //0b00000010;  // 1 0 to 1A and 2A pins to rotate motor anticlockwise
				lcd_out(1,1,"Motor is Running");
				lcd_out(2,1,"Anti-Clockwise");
				
			}
			OCR0=i;
		}
		PORTA=0x00;  // 0 0 to stop motor 
		lcd_out(1,1,"Motor is OFF");
		lcd_out(2,1,"Caution");
	}
}
ISR(INT0_vect)
{
	i=i+20;  
}

Buid and Run the code in Microchip Studio -

Simulation Output -

1) when power switch is off & motor is also off

2) When power switch is clossed and motor runnung clockwise

3) When Direction control switch is clossed and motor running anti-clockwise