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

AIM

• 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

Requirment

• Microcontroller Atmega32
• DC motor
• L293 motor Drive
• Hd44780 LCD Display
• Power Switch
• 10 k ohm Resistor

Software Requirement

• SimulIDE
• Microchip Studio

Procedure

With the help of Microchip Studio we are going to write AVR bare metal code. For Display output we are going to interface LCD to Atmega32 Microcontroller. The Direction of DC motor is controlled with the help of L293 motor Drive. The speed of the motor is controlled by the input supply voltage. For simulation of developed project can be excecuted with the help of SimulIDE.

AVR CODE:

#include <avr/io.h> // Preprocessor Directive of AVR input and output
#define F_CPU 16000000ul //Macro definition of crystal freq
#include "avr/interrupt.h" // Preprocessor Directive of AVR external interrupt
#include <util/delay.h> //delay function
#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 pin 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 resistor select(rs)
#define RS_low PORTD&=~(1<<5) //d5 pin is used for resistor select(rs)
#define EN_high PORTD|=(1<<6) //d6 pin is used for enable
#define EN_low PORTD&=~(1<<6) //d6 pin is used for enable
unsigned char i;
void lcd_cmd(char cmd) // command for LCD display
{
lcd_port=(cmd&0xf0); //Masking 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); //masking 4 bits for bit LCD mode//
RS_high; //access data register
EN_low;
_delay_ms(1);
EN_high;
lcd_port=((data<<4)&(0xf0)); //masking 4 bits for bit LCD mode//
RS_high; //access data register
EN_low;
_delay_ms(1);
EN_high;
}
void lcd_init()
{
lcd_cmd(0x28);
_delay_ms(5); //used for 4 bits LCD mode //
lcd_cmd(0x02);
_delay_ms(5); //return the cursor to 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 1st line //
}
void cursorpos(char x, char y)
{
if ((x<1||x>2)||(y>16)||(y<1)) //condition will check the rows and 16 columns
{
x=1; //x=rows
y=1; //y=columns
}
if (x==1)
{
lcd_cmd(0x7F+y);
}
else //(x=2)
{
lcd_cmd(0xBF+y);
}
}
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 are configuring the adc value
{
unsigned int a, result;
ADMUX=channel; //here we are going to use which channel we need to select in mux here using 2 bit
ADCSRA=0X80; // control and 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 (0x40means interrupt pin)
a=ADCL; //dummy data type a and a is stored the adcl register (ADC0-ADC7)
result=ADCH; //store the high value (ADC8-ADC9)
result=result<<8; //to get proper result or aligned value we need to do left shift
result=result|a; //we are adding the ADCL+ADCH to get 16 bits
return result;
}
int main(void)
{
DDRB=0xFF; // declaring all 8 pins as output
DDRA|=((1<<0)|(1<<1)); // declaring A0 and A1 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 pre scalar
GICR=(1<<INT0); // using into for interrupt
MCUCR=0X02; // make interrupt negative edge triggered
sei(); //enable global interrupt
lcd_init(); // initialized LCD
while (1)
{
while(pw==0) //continue till push button is released
{
if (sw_dir==0) // if the direction control push button is released
{
PORTA=0b00000001; //10 respective 1A 2A pins to rotate in clockwise direction
lcd_out(1,1,"Motor ON-CLW"); // running clockwise direction
}
else
{
PORTA=0b00000010; //10 respective 1A 2A pins to rotate in anti-clockwise direction
lcd_out(1,1,"Motor ON-ACL"); // running anti-clockwise direction
}
OCR0=i; // i increase in ISR, the corresponding value is to be loaded into OCR0
}
PORTA=0X00; //0 0 to respective 1A 2A pins to stop condition
lcd_out(1,1,"Motor is_OFF");
}
}
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
}