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[PIC32] configTICK_RATE_HZ and tick hook

Posted by Angelo on February 20, 2012
Hello!
I have a little problem using the tick hook.
I set configTICK_RATE_HZ to 200 and I want to execute some istructions every 2 seconds.
My tick hook method is the follow:

void vApplicationTickHook(void)
{
static unsigned int tickCount = 0;

tickCount++;
if (tickCount >= (2 * configTICK_RATE_HZ))
{
tickCount = 0;
...
// my code
...
}
}

The problem is that "mycode" is executed every 1 seconds.
If i want to execute it every 2 seconds i must change my condition to:
if (tickCount >= (4 * configTICK_RATE_HZ)) .
I don't understand why.
Thanks in advance.
Regards.

RE: [PIC32] configTICK_RATE_HZ and tick hook

Posted by Richard on February 20, 2012
I would assume your tick interrupt is executing at twice the frequency you think it is. Have you verified the tick frequency you are using? The simplest method, if you have the equipment, is to simply pulse an GPIO output from the tick hook and measure it on an oscilloscope.

Consider using a software timer to implement the same functionality.

Regards.

RE: [PIC32] configTICK_RATE_HZ and tick hook

Posted by Angelo on February 24, 2012
Thanks a lot for the answer!


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