I'm using the PIC 18F4680 in college for my project. I have a simply piece of code below for toggling a port;

void main() {
   TRISC =  0x00;               //When you invert the tri-state, it turns on all outputs on the board
   while(1){
   PORTC = 0x55;                // Hex number for 8 LED's    (01010101 in Binary, corresponding to LED position)
   Delay_ms(1);              // Delay of 1000ms or 1 sec
   PORTC = 0xAA;                // Hex number for 8 LED's    (10101010 in Binary, corresponding to LED position)
   Delay_ms(1);              // Delay of 1000ms or 1 sec
}
}

I tested the pin at the time with a multimeter and the pin was pulsing between 0V - 5V. Im just wondering is there a way of finding that pin using the code above. When I add 0x55 + 0xAA = 0xFF which means that all the ports are on. But I remember at the time that I was only getting that pulse on one pin.
Thanks.

Moderators note: Please use code tags for pieces of code

 

Hi,
When 0xFF is written ,which pin is toggling exactly?
Use LATx to write values and PORTx to read values.

AK

 

Why do you think "Delay_ms(1);" is a "// Delay of 1000ms or 1 sec"

I do believe "Delay_ms(1);" will be a delay of 1ms or 0.001 sec.

A .001 sec delay makes it rather hard for a multimeter to make any sort of reading, though it may see something on the AC scale given the 500Hz square wave.

 

That's the thing, I can't remember which pin was being toggled. It was being programmed by the EasyPIC V7 board and was written on that board first. I could see the LED's flashing on PORTC of the EasyPIC in the binary sequence above in the code. Just when the code was transferred to my own board that I was programming it created a pulse on one of the pins, which pin I cannot remember. I don't think its visable from my code either. I don't have the EasyPIC board myself so I cannot check at home.

Sorry I was messing around with the code and changed the delay but never bothered changing the delay comment around, I know that it is a 1ms delay. Thanks.

 

MPLAB has a PIC simulator built in that will work just fine to test which pins wiggle, and it is only a download away.

 

Do I just paste my code in and it will give me a result?

 

MPLABX

no you need to select the Simulator then compile + start simulation session.

18F different than 16F needs LAT registers to be set, as well delay isnt really good you should use a timer interrupt.