Quality RTOS & Embedded Software

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




Loading

Semaphore times out

Posted by ARMinator on March 22, 2009
Hi,

I have added a tick hook that counts ticks and give a semaphore periodically using xSemaphoreGiveFromISR.

A task waits on this semaphore using xSemaphoreTake and the maximum delay (portMAX_DELAY).
I have an LED that shows when the semaphore is given and an LED showing when the semaphore is taken.
The semaphore is given consistently from the ISR (the ISR LED blinks). You would expect the task LED to blink too... However the semaphore is only taken once from the task. All other tentatives to take the semaphore pend forever, or timeout if I use a timeout value other than portMAX_DELAY.

This issues occurs whenever I use binary or counting semaphores.

Any idea what is going wrong?

Thanks

RE: Semaphore times out

Posted by ARMinator on March 22, 2009
I thought I would also say that I tried to add the following code and it still fails:

xSemaphoreGiveFromISR(mySemaphore, &dummy);
if(pdTRUE == dummy)
{
portYIELD_FROM_ISR();
}

RE: Semaphore times out

Posted by Dave on March 22, 2009
Which port are you using (CPU and compiler). Which version of FreeRTOS are you using? Can you post your code?


[ 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