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.

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.

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.

Code for the Model:

#include <avr/io.h>				//we are using I/O registers of AVR
#define F_CPU 16000000ul			// define the crystal frequency
#include "avr/interrupt.h" 		// we are using external interrupt pin
#include <util/delay.h>			// delay function purpose
#define sw_dir (PIND & (1<<1))  // d1 pin is declared as push button for direction control.
#define sw_dspd (PIND & (1<<2)) // d2 pin is declared as push button for speed control.
#define pw (PINC & (1<<3))	    // c3 is declared as push button for power ON/OFF

#define lcd_port PORTB			//PORTB pins are for LCD data
#define RS_high PORTD |= (1<<5) // d5 pin is used for Register Select(RS)
#define RS_low PORTD &=~ (1<<5) // d5 pin is used for RS
#define EN_high PORTD |= (1<<6) // d6 pin is used for Enable
#define EN_low PORTD &=~ (1<<6) // d6 pin is used for En.
unsigned char i;


void lcd_cmd(char cmd) //command for lcd display
{
	lcd_port = (cmd & 0xf0); //4 bits for 4 bit lcd mode
	RS_low; 
	EN_low;
	_delay_ms(1); //after 1ms disable lcd
	EN_high; //enable the lcd
	lcd_port = ((cmd<<4) & (0xf0)); //lcd port
	RS_low; 
	EN_low;
	_delay_ms(1); //after 1ms disable lcd
	EN_high; //enable the lcd
}

void lcd_data (char data) //send the data to lcd
{
	lcd_port = (data & 0xf0); //4 bits for 4 bit lcd mode
	RS_high; //access data register
	EN_low;
	_delay_ms(1);
	EN_high;
	lcd_port = ((data<<4) & (0xf0)); //4 bits for 4 bit lcd mode
	RS_high; //access data register
	EN_low;
	_delay_ms(1);
	EN_high;
}

void lcd_init()
{
	lcd_cmd(0x28);// 38 means 2 lines & 5x7 matrix
	_delay_ms(5);
	lcd_cmd(0x02); // return 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 the display cursor
	_delay_ms(5);
	lcd_cmd(0x80); // force cursor to begin from 1st line
	_delay_ms(5);
}

void cursorpos(char x,char y)
{
	if((x<1 || x>2) || (y<1 || y>16)) //condition will checks the 2 rows and 16 columns
	{
		x=1; //x= row
		y=1; //y= column
	}
	if(x==1)
	{
		lcd_cmd(0x7F + y); //{ 80-1 = 7F}  for starting the 1st line hex decimal value (80) {y we r using the 7F+y means we need to dtart from that column}
	}
	else //(x==2)
	{
		
		lcd_cmd(0xBF + y); //{0C-1 = 0B}   for starting the 2nd line, 2nd row.
	}
}

void lcd_print(char row, char column, unsigned int value, int digits)
{
	unsigned int temp;
	unsigned int unit;
	unsigned int tens;
	unsigned int hunderd;
	unsigned int thousand;
	unsigned int million;
	
	unsigned char flag = 0;
	
	if(row == 0 || column == 0)
	{
		cursorpos(1,1);
	}
	else
	{
		cursorpos(row,column);
	}
	
	if(digits == 5 || flag == 1) //it will be in million place
	{
		million =value/10000 + 48; //{10000+48 means assic value of zero is 48} 49=1,50=2 ....
		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;
		hunderd = temp % 10 + 48;
		lcd_data(hunderd);
		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) // more than 5 is more than million
	{
		lcd_data('e');
	}
}


void lcd_out(char x, char y, char *str) //here we are checking which position we want to print
{
	cursorpos(x,y);
	while(*str)
	{
		lcd_data(*str);
		str++;
	}
}

int adc_read(char channel) // we r configuring the adc value
{
	unsigned int a, result;
	ADMUX = channel; // here we r going to use which channel we need to select in mux here using 2 bit
	ADCSRA = 0X80; //control & status register to enable the adc conversion ,enable the interrupt flag, adc interrupt. ADEN=1
	ADCH = 0X00;  // showing the value 0 or clearing the adc register
	ADCL = 0x00; // showing the value 0
	ADCSRA |= (1<<6); //  to start the conversion 6 bit ADSC high
	while((ADCSRA & 0x40)  != 0); // when the conversion become zero means conversion of adc (0x40 means interrupted pin )
	a= ADCL; //dummy data type a and ais stored the ADCL register (ADC0-ADC7)
	result = ADCH; // Store the high value  (ADC8-ADC9)
	result = result<<8; //to get proper result or alined value we need to do left shift
	result = result | a ; // we r adding the ADCL + ADCH to get the 16 bits
	return result;

}

int main(void)
{
	DDRB = 0XFF;                    //Declaring all 8-pins as output.
	DDRA |= ((1<<0)| (1<<1));		//Declaring A0 & A1 pins as output.
	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);					//enabling internal pull up resistor for D2.
	PORTC |= (1<<3);					//enabling internal pull up resistor for D3.
	i=64;				            //initializing i=64 because we are running the motor with 25% duty cycle.
	TCCR0=0X61;						//Non-Inverting mode, PWM phase correct mode,NO prescalars.
	GICR=(1<<INT0);					//using INT0 for interrupt
	MCUCR=0X02;						//make interrupt negative edge triggered
    sei();				            //Enable global interrupt
	lcd_init();						//Initialize lcd
    /* Replace with your application code */
    while (1) 
    {
		while(pw==0)                         //continue till the push button is released.
		{
			if(sw_dir == 0)					//if the direction control push button is released.
			{
				PORTA = 0b00000001;			// 1 0 to respective 1A 2A pins to rotate in clockwise direction.
				lcd_out(1,1,"Motor is Running");
				lcd_out(2,3,"Clockwise");
            }
			else
			{
				PORTA = 0b00000010;			// 1 0 to respective 1A 2A pins to rotate in Anti-Clockwise direction.
				lcd_out(1,1,"Motor is Running");
				lcd_out(2,3,"Anti-Clockwise");
			}
			OCR0 = i;					    //i increases in ISR, the corresponding value is to be loaded into OCR0.
			
	}
	
	PORTA = 0x00;						  // 0 0 to respective 1A 2A pins to Stop 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 duty cycle also increases. i increases by 20 in each push//
                                       // and the corresponding value is to be loaded into OCR0 in while loop//
}