Quality RTOS & Embedded Software

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


PIC24 C30 ISR queue failure in minutes

Posted by Chip Mauler on May 30, 2011
My test collects adc data under 100Hz interrupt (using xQueueSendFromISR ) and the highest priority task unloads the data but the queue only works for a few minutes. I see the interrupt routine still gets executed and another lower priority delay based task is unaffected.
I have changed queue length, task priority, stack size etc read numerous examples and I have stack check enabled, but I'm at a loss when the queue ceases to indicate received after a few thousand correct operations!
Latest FreeRTOS V7.0.1
Copied ISR from PIC24 port demo serial handler
Vindicated hardware, as I substituted the queue with a C based creation based on shared variable with flags, and it ran overnight without issue.

Suggestions for possible/typical reasons or line of experimentation to determine cause?
Thank you for your time and consideration

RE: PIC24 C30 ISR queue failure in minutes

Posted by Richard on May 30, 2011
Do you have the priority of the ADC interrupt set to configKERNEL_INTERRUPT_PRIORITY (the lowest priority)? If not, then set it to configKERNEL_INTERRUPT_PRIORITY and give it another try.

See the "RTOS Port Specific Configuration" section on http://www.freertos.org/portpic24_dspic.html


RE: PIC24 C30 ISR queue failure in minutes

Posted by Chip Mauler on May 30, 2011
Thanks, it did the trick. Frustrating when you spend extra time to sort out a problem but tiredness limits you.

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

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

Latest News

FreeRTOS v10.2.1 is available for immediate download. MIT licensed, includes 64-bit RISC-V, NXP Cortex-M33 demo, Nuvoton Cortex-M23 demo & STM32H745 dual core (AMP) demo.

NXP tweet showing LPC5500 (ARMv8-M Cortex-M33) running FreeRTOS.

View a recording of the "OTA Update Security and Reliability" webinar, presented by TI and AWS.


FreeRTOS and other embedded software careers at AWS.

FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

Cadence Tensilica Cortes

Espressif ESP32

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

Xilinx Microblaze and Zynq partner