PIC 12F675 on digital IO problem..

[nirajb]

Dear Friend,

i am starting on PIC first time. here is my code for blinking LED using timer0 on Hi-tech compiler (free version)
My question:
--> LED is blinking when GPIO is not assign first time in code...
but
--> LED is not blinking when GPIO is assign first time in code...

Here is sample code when GPIO is assign first time (LED not blinking)
Code:-
#include<htc.c>
char tick_count;
int delay;
void main()
{ // int start....
CMCON=0x07;
ANSEL=0x00;
TRISIO=0x00;
OPTION=0x84;
INTCON=0xA0;
TMR0=0x00;
GPIO=0x00; //This line is problem for me...
//int end
while(1)
{
if(tick_count>=50)
{
tick_count=0;
delay++;
switch(delay)
{
case 1:
GPIO=0x00;
break;

case 2:
GPIO=0xff;
delay=0;
break;

}
}
}
}

void interrupt x(void)
{
if(TOIE && TOIF)
{
TOIF=0;
TMRO=0;
++tick_count;
}
}


Note:= above code not working for me because of I int. GPIO before while..
but if you lable it then this code working...

can you help me.. ??
any reg. i forgot then please tell me...

Regards,
Niraj

 

[nirajb]

more detail is here...

mikroC compiler also give same ...
my hardware:-
internal 4MHz osc.
Led +ve(Anode) connected with +5V supply with res. and Led -ve connected with Port pin.

Niraj

 

[rajbex]

Remember, GP3 is Input Only pin. You cannot write to it. Check the datasheet.

-Raj
Experiments with PIC16F628A

 

[AllVol]

I could be wrong because your code is jumbled, but I believe you are missing one curly (end) bracket in the segment before your interrupt.

Check it with MPLAB.