Project 1 - Controlling a DC motor using PWM and monitoring its Running status
PROJECT 1:-
DEVICE USED:-
atmega32 microcontroller.
DC motor
Two push bottun
One On/Off switch
One Hd44780 (2 * 16) display
L239 Half H-Bridge
Simulation is done on SimulIDE
WORKING:
In this project LCD is work in 4 bit mode. LCD is showing status of DC motor which is connected with H-Bridge. With the help of this H-Bridge we can run moter in both directions.
OPERATION:
When ON/OFF switch is in OFF state then by pressing puch button motor will run in Clock wire direction.
When ON/OFF switch is in ON state then in this case by pressing puch button motor will run in Anti clock wise directon.
When ever puch button which is connected to PORT-D Pin-2 then speed of motor is increase.
CODE:-
#include <avr/io.h> // Including AVR Input/Output header file
#define F_CPU 16000000ul //define the CPU frequency
#include "avr/interrupt.h" // Including AVR interrupt header file
#include <util/delay.h> //Including Delay header file
#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 pin of LCD (high)
#define RS_low PORTD&=~(1<<5)
#define EN_high PORTD|=(1<<6) //d6 pin is used for enable pin of LCD
#define EN_low PORTD&=~(1<<6)
unsigned char i; // Creating a global variable
void lcd_cmd(char cmd) // This function is to use LCD in command Mode
{
lcd_port=(cmd&0xf0); //Masking 4 bits for 4 bit LCD mode//
RS_low; // RS is low in command mode
EN_low; // setting EN bit low
_delay_ms(1); //small delay
EN_high; // again setting high to same EN bit
lcd_port=((cmd<<4)&(0xf0));
RS_low; // RS is low in command mode
EN_low; // making EN pin of LCD low
_delay_ms(1); // small delay
EN_high; // again setting HIGH to same bit
}
void lcd_data(char data) //This function is to use LCD is data mode
{
lcd_port=(data &0xf0); //masking 4 bits for bit LCD mode//
RS_high; //RS is high in data mode
EN_low; // setting EN bit low
_delay_ms(1); // small delay
EN_high; // again set high
// reapting
lcd_port=((data<<4)&(0xf0));
RS_high;
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 2 and 16 columns
{
x=1; //x=rows = 1
y=1; //y=columns = 1
}
if (x==1)
{
lcd_cmd(0x7F+y); //{80-1=0B}for starting the first list hex decimal value(80){y we are the 7F+y means we need to start from that column
}
else
{
lcd_cmd(0xBF+y); //{0C-1=0B} for starting the second 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); // setting at our desire location
while (*str) // printing string till
{
lcd_data(*str);
str++; // printing word by word
}
}
int adc_read(char channel) // This function is to configure ACD
{
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 ais 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(); //enabling interrupts
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; //respective 1A 2A pins to rotate in clockwise direction
lcd_out(1,1,"Motor ON-CLW"); // running clockwise direction
}
else
{
PORTA=0b00000010; //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) // interrupts
{
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
}
WHEN MOTOR IS OFF:-
WHEN MOTOR IS RUNNING IN CLOCK WISE DIRECTION:-
WHEN MOTOR IS RUNNING IN ANTI CLOCK WISE:-
MOTOR SPEED IS INCREASES:-
