Thursday, July 22, 2010

Atmega16 : Square wave Frequency Counter: CodeVision Code

/*****************************************************
Chip type               : ATmega16
Program type            : Application
AVR Core Clock frequency: 8.002000 MHz
Memory model            : Small
External RAM size       : 0
Data Stack size         : 256
Written By                :(Vikas Sharma)
*****************************************************/

#include
#include
#include
// Alphanumeric LCD Module functions
#asm
   .equ __lcd_port=0x15 ;PORTC
#endasm
#include
//Declare your global variables here
  unsigned char str_buffer[20];
unsigned int CNT=0;
int FLAG=0;
//Timer 1 overflow interrupt service routine
interrupt [TIM1_OVF] void timer1_ovf_isr(void)
{
       // PORTD.7=~PORTD.7;                       //High-Low pulse
       lcd_clear();
       sprintf(str_buffer,"FREQ = %u",CNT);
       lcd_puts(str_buffer);
       CNT=0;
        //TCNT1=55535;
        TCNT1=57723;
}




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=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
PORTB=0xFF;
DDRB=0x00;          //input   push buttons

// Port C 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
PORTC=0x00;
DDRC=0xff;           //output         lcd

// Port D 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
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: Timer1 Stopped
// Mode: Normal top=FFFFh
// OC1A output: Discon.
// OC1B output: Discon.
// Noise Canceler: Off
// Input Capture on Falling Edge
// Timer1 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;

//TCNT1=55535;
 TCNT1=57723;
TCCR1A=0b00000000;
TCCR1B=0b00000101;   //SELECT CLOCK HRER CS


// Timer/Counter 2 initialization
// Clock source: System Clock
// Clock value: Timer2 Stopped
// Mode: Normal top=FFh
// OC2 output: Disconnected
ASSR=0x00;
OCR2=0x00;
TCCR2=0b00000101;
TCNT2=0xFF;

// External Interrupt(s) initialization
// INT0: Off
// INT1: Off
// INT2: Off
MCUCR=0x00;
MCUCSR=0x00;

// Timer(s)/Counter(s) Interrupt(s) initialization
TIMSK=0b00100100;                  //6 bit timer2  0 bit tiemr0   2 bit timer1 

// Analog Comparator initialization
// Analog Comparator: Off
// Analog Comparator Input Capture by Timer/Counter 1: Off
ACSR=0x80;
SFIOR=0x00;
#asm("sei")

lcd_init(20);
lcd_putsf("FREQ-");
while (1)
      {
      // Place your code here
           if (PINB.4 == 0 && FLAG==0)
            {
                CNT=CNT+1;
                FLAG=1; 
            }
             if (PINB.4 == 1)
             {
                FLAG=0;
             }
      //PORTD.0=PINB.4;
     // delay_ms(1000);

      };
}