Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem TCP & FAT




Loading

[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!


[ Back to the top ]    [ About FreeRTOS ]    [ Sitemap ]    [ ]




Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.

Latest News

FreeRTOS kernel V10 is available for immediate download. Now MIT licensed.


FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

IAR Partner

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

STMicro RTOS partner supporting ARM7, ARM Cortex-M3, ARM Cortex-M4 and ARM Cortex-M0

Texas Instruments MCU Developer Network RTOS partner for ARM and MSP430 microcontrollers

OpenRTOS and SafeRTOS