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

AIM:

• 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.

DC Motor:

• A DC motor is defined as a class of electrical motors that convert direct current electrical energy into mechanical energy.
• When kept in a magnetic field, a current-carrying conductor gains torque and develops a tendency to move.
• Thus when electric fields and magnetic fields interact, a mechanical force arises.
• This is the principle on which the DC motors work.

L293 Motor Driver:

• L293d IC is known as a motor driver.
• It is a low voltage operating device like other ICs.
• The other ICs could have the same functions like L293d but they cannot provide the high voltage to the motor.
• L293d provides the continuous bidirectional Direct Current to the Motor.
• The Polarity of current can change at any time without affecting the whole IC or any other device in the circuit.
• L293d has an internal H-Bridge installed for two motors

PROGRAM :

/*

* project-1.c

*

* Created: 08-12-2022 19:24:39

* Author : lavanyajarpula715

*/

#include <avr/io.h> //we are using I/O registers of AVR

#define F_CPU 16000000L // 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);// used for 4 bit lcd mode

_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>16 || y<1 )) //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_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 prescalar.

GICR=(1<<INT0); //using INT0 for interrupt

MCUCR=0X02; //make interrupt negative edge triggered

sei(); //Enable global interrupt

lcd_init(); //Initialize lcd

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 ON- CL "); //Running clock wise direction

}

else

{

PORTA = 0b00000010; // 1 0 to respective 1A 2A pins to rotate in Anti-Clockwise direction.

lcd_out(1,1,"Motor ON- ACL");

}

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 TURNOFF");

}

}

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//

}

Components required while simulation:

ATmega32:1

Keys(L293 Quadruple half-H driver):1

Display(hd44780):1

Resistor:1

Switch(push):3

Sourse(ground):3

DC motor:1

OUTPUT:1

When power circuit on: LCD display shows that ----> ”MOTOR IS TURN OFF”

All switches : “OFF”

OUTPUT:2

When motor switch is :”ON”-->MOTOR RUNS

LCD display shows that ----> ”MOTOR ON -CL (motor runs in clockwise direction with low speed)”

OUTPUT:3

When motor switch is :”ON”-->MOTOR RUNS

DIRECTION SWITCH :"ON"

LCD display shows that ----> ”MOTOR ON -ACL (motor runs in clockwise direction)”

OUTPUT:4

When motor switch is :”ON”-->MOTOR RUNS

DIRECTION SWITCH: "ON"

LCD display shows that ----> ”MOTOR ON -ACL (motor runs in clockwise direction)”

Speed control switch :"ON"---> MOTOR RUNS WITH HIGH SPEED