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PIC32 delay help

sanyika95

Hello everyone!

 

I just started to learn PIC32 programming with a PIC32 Ethernet Starter kit. I wanted to blink its led, 1 second on - 1 second off.

 

Here is the code for the delay:

#define USHORT unsigned short

void delayMs(USHORT milisec) {
    T1CON = 0x8010;
    TMR1 = 0x00;
    USHORT i = 0;
    PR1 = 0x40;
    while(i != milisec) {
        while(TMR1) {
        }
        i++;
        TMR1 = 0x00;
    }
    T1CON = 0x00;
    return;
}

 

It just works (or it looks like to work, I haven't measured it with an oscilloscope, just with a "stopwatch") and I don't know why. Can someone explain me?

 

 

The datasheet of the kit:

http://ww1.microchip.com/downloads/en/DeviceDoc/61166A.pdf

 

The datasheet of its PIC:

http://ww1.microchip.com/downloads/en/devicedoc/60001156j.pdf

Parents

  • I would suspect that the WDT is kicking in causing a reset, I have seen this before.

    If you want a good timer then use the call back feature from the Harmony and use the DRV_Handle call back feature, this then allows you to pass a value to the timer function that runs in the background and interrupts after the elapsed time. As there are so many different approaches to this, If you have a Core timer available you can calculate the time in ms from this although you will not be able to exit the loop until it ends, this is the simplest way but does stop the rest of the code from running and if using communication or other important tasks you run the risk of a WDT reset or data being missed.

     

    I hope this helps.

     

    As a point Microchip changed the function __delay_   And you have to create this yourself. I will try finding some of my code and post it image

     

    Mike Clapham.

  • in reply to mike-0rc

    I have scoured my home PC and I have no examples as I have not done one on this PC yet, Instead you can look at the following as there are too many steps to write down here (You have to edit a lot of headers and c files to implement the timer call back (I started here while learning how to implement them in to my code).

    https://microchipdeveloper.com/harmony:example-tmr-sys-mz-ef-sk  As I am using a high end PIC32MZ2048EFH250 you may need to modify the code or have a look at the code (They should be cross device compatible) to get an idea on how this works.

     

    Regards,

    Mike Clapham.

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