AVR microcontroller PWM controls the speed and forward and reverse rotation of DC motor

Controlled by uln2003, the following is the simulation schematic diagram:


Source program:

/*****************************************************

This program was produced by the

CodeWizardAVR V2.03.4 Standard

Automatic Program Generator

?Copyright 1998-2008 Pavel Haiduc, HP InfoTech srl

http://www.hpinfotech.com

Project : 

Version : 

Date    : 7/26/2009

Author  : 

Company : 

Comments: 

Chip type           : ATmega32

Program type        : Application

Clock frequency     : 12.000000 MHz

Memory model        : Small

External RAM size   : 0

Data Stack size     : 512

*****************************************************/

#include

#include

// Declare your global variables here

void Motor_Speed (int x)

{

switch (x)

   {

    case 0:    PORTB = 0x00;

               break;

    case 6:    PORTB = 0x08;

               break;                

    case 12:   PORTB = 0x28;

               break;

    case -6:   PORTB = 0x10;

               break;                        

    case -12:  PORTB = 0x30;

               break;                    

   }

}

//////////////////////////////////////////////////////////////////

void main(void)

{

// Declare your local variables here

// Input/Output Ports initialization

// Port A initialization

// Func7=In Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=In 

// State7=T State6=T State5=T State4=T State3=T State2=T State1=T State0=T 

PORTA=0x00;

DDRA=0x00;

// Port B initialization

// Func7=Out Func6=Out Func5=Out Func4=Out Func3=Out Func2=Out Func1=Out Func0=Out 

// State7=0 State6=0 State5=0 State4=0 State3=0 State2=0 State1=0 State0=0 

PORTB=0x00;

DDRB=0xFF;

// Port C initialization

// Func7=Out Func6=Out Func5=Out Func4=Out Func3=Out Func2=Out Func1=Out Func0=Out 

// State7=0 State6=0 State5=0 State4=0 State3=0 State2=0 State1=0 State0=0 

PORTC=0x00;

DDRC=0xFF;

// Port D initialization

// Func7=Out Func6=Out Func5=Out Func4=Out Func3=Out Func2=Out Func1=Out Func0=Out 

// State7=0 State6=0 State5=0 State4=0 State3=0 State2=0 State1=0 State0=0 

PORTD=0x00;

DDRD=0xFF;

// Timer/Counter 0 initialization

// Clock source: System Clock

// Clock value: Timer 0 Stopped

// Mode: Normal top=FFh

// OC0 output: Disconnected

TCCR0=0x00;

TCNT0=0x00;

OCR0=0x00;

// Timer/Counter 1 initialization

// Clock source: System Clock

// Clock value: Timer 1 Stopped

// Mode: Normal top=FFFFh

// OC1A output: Discon.

// OC1B output: Discon.

// Noise Canceler: Off

// Input Capture on Falling Edge

// Timer 1 Overflow Interrupt: Off

// Input Capture Interrupt: Off

// Compare A Match Interrupt: Off

// Compare B Match Interrupt: Off

TCCR1A=0x00;

TCCR1B=0x00;

TCNT1H=0x00;

TCNT1L=0x00;

ICR1H=0x00;

ICR1L=0x00;

OCR1AH=0x00;

OCR1AL=0x00;

OCR1BH=0x00;

OCR1BL=0x00;

// Timer/Counter 2 initialization

// Clock source: System Clock

// Clock value: Timer 2 Stopped

// Mode: Normal top=FFh

// OC2 output: Disconnected

ASSR=0x00;

TCCR2=0x00;

TCNT2=0x00;

OCR2=0x00;

// External Interrupt(s) initialization

// INT0: Off

// INT1: Off

// INT2: Off

MCUCR=0x00;

MCUCSR=0x00;

// Timer(s)/Counter(s) Interrupt(s) initialization

TIMSK=0x00;

// Analog Comparator initialization

// Analog Comparator: Off

// Analog Comparator Input Capture by Timer/Counter 1: Off

ACSR=0x80;

SFIOR=0x00;

while (1)

      {

            Motor_Speed(6);

            delay_ms(3000);

            Motor_Speed(12);

            delay_ms(3000);

            Motor_Speed(-6);

            delay_ms(3000);

            Motor_Speed(-12);

            delay_ms(3000);

            Motor_Speed(0);

            delay_ms(3000);     

      };

}