IR+PIC 16f877a counter mode

Hai friends,

In my project i interface an IR module with PIC 16F877a,This system is used for counting motro rotation.
PIC in Counter mode using timer1.Now the problem is that when i connect manually to an IR then PIC count properly.But when it connected to the motor it reads wrong count.OR it does not work properly.
Here i post my code.


CODE


int i=0,j=0,k=0;
void main()
{
trisc=0xff;
trisb=0;
t1con=0x0b;
tmr1l=0;
tmr1h=0;
while(1)
{
i=tmr1l;
if(i<50)
{
portb.f0=1;

}
if(i==50)
{
portb.f0=0;
portb.f1=1;
Delay_ms(100);
portb.f1=0;
portb.f2=1;
tmr1l=51;
}
if(i>100)
{
portb.f1=0;
tmr1l=0;
}

}
}

when i connect
manually to an IR then PIC count properly.But when it connected to the
motor it reads wrong count.

Click to expand...

Could you explain your connections ? What you mean by 'when i connect manually to an IR'?
How you are connecting it to motor?

Didn't understood properly but just assuming,is the problem hits you when you want to count for 50 or more?

Hi ansarmytheen,

You may want to checkout Romel's thread:

some questions motor speed monitoring

The thread covers the details of designing and constructing a tachometer (RPM meter).

BigDog

vinodstanur said:

Could you explain your connections ? What you mean by 'when i connect manually to an IR'?
How you are connecting it to motor?

Click to expand...

Manually means

if we remove the ir module from motor and it connected with pic.Then we cut the the IR rays by a metal or anything then the counting is correct.

please post photos of your hardware. .
i did not get you be more clear!!