led flashing using timer in on atmega

[Disha Karnataki]

this is my code :

#include <avr/io.h>
  void tim0(unsigned int);
  int main(void)
  {
    DDRB=0X0F;     //making lower nibble o/p port
    PORTB=0X00;    
	TCCR0=0X01;    //timer with no prescaler
	TCNT0=0X00;    //initial count value=0x00
	while(1) 
	{  
	PORTB=0X0A;    //portb has 0x0a value
	tim0(90);       //set some delay
	PORTB=0X00;     //portb value =0x00
	tim0(90);      //set some delat
	}
	}
	void tim0(unsigned int x)       //sub routine for delay
	{
	unsigned int i;              
	
	for(i=x;i>0;i--)               
	{
	    
	     if(TCNT0!=190);        //loop till tcnt value becomes 190
		 TCNT0=0;           //reset the tcnt value back to zero
    }                     //continue this loop till i=0
	}

what is mistake in this code as only 0X0A value is shown on PORTB.

 

[udayan92]

The code seems fine.I think it is due to the low delay that you have put..the flashing is happening at a rate so fast,your eyes perceive the LEDs to be on all the time.Increase the delay from 90 to atleast 300,and let us know what happens in that case,

 

[Disha Karnataki]

The code seems fine.I think it is due to the low delay that you have put..the flashing is happening at a rate so fast,your eyes perceive the LEDs to be on all the time.Increase the delay from 90 to atleast 300,and let us know what happens in that case,

i have tried with 1000-9000 range but the result is same