Led flashing for one second using Mikro c

[Rajinder]

Hi All,
I am currently writing some code in C on Mikro C platform. The program is supposed to doba led chaser on port D of pic18f54k20, I am using debug PCB on pickit 3. Then it's supposed to flash led on port c bit 0 every second. It does the led chaser routine but never goes into the interrupt.
I have attached the code, any help would be appreciated. Note in the interrupt routine I gave truedt both intcon 0x20 and intcon 0x02 to clear the interrupt flag.
Thanks in advance.
Rajinder

 

[Harald Kapp]

The code is almost illegible in the Jpeg.
Please use the Insert...->Code function (docuemnt symbol on top, left of teh diskette symbol) to paste the code in a well readable format.

 

[Rajinder]

Ok will do.
Thanks.

 

[Rajinder]

Here is the code again.

 

[Arouse1973]

I can't find the PIC18F54 on Microchips website, is the part number correct?
Adam

 

[Rajinder]

It's a pic 18f45k20. The one used on the debug express that comes with pic kit 3. Sorry for the wrong info.

 

[Arouse1973]

Where are you setting up the interrupts? I can't see from your code, can you explain?
Adam

 

[Rajinder]

I set up, the prescaler, timer0 to be in 8 bit mode, I then set the intcon register to 0xA0, enable global interrupts and enable timer0 interrupt. It's in the main code.

 

[Arouse1973]

Ok yes see it now, missed it first time.
Adam

 

[Arouse1973]

How are you telling the compiler that the routine "Interrupt" is your 0x08 interrupt address? I am not familiar with Micro C.
Adam

 

[Sadlercomfort]

Most of your code looks fine to me.
Have you tried putting "Timer0_ISR" at the start of the interrupt routine like so:

void interrupt Timer0_ISR(void)
{
}

I also noticed your using TMR0L, I'm not familiar with setting up 8-bit or 16-bit modes.. but I assume if you've set it to 8-bit you would just use TMR0.

 

[Sadlercomfort]

I would also check that your prescaler is correct, I used to use this formula.

Freq. out = Freq. osc / [prescaler * (256 - TMR0) * count]


Maybe set Prescaler to 1/1 and create a count for 31250. I might be wrong


Freq. out = 8MHz / [ 1/1 * (256 - 0) * 31250 ]

Freq. out = 8MHz/256 * 31250

Freq. out = 1Hz

 

[Rajinder]

Ok, thanks will have a look. I tried just lighting an led in the interrupt, first thing. To see if the interrupt was being serviced, but it didn't light. I think the issue may be that, not sure. I am new to Mikro c.

 

[Sadlercomfort]

There's alot of things which can go wrong when writing code, I'm fairly new to C aswell.. only be writing C since august.

Generally I've found that writing small chunks of code first can help, like you said lighting the LED first is a good idea.

I would try lighting the LED without an interrupt first, so you know your ports are setup correctly.