Quality RTOS & Embedded Software

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


FreeRTOS SW Timers inaccurate

Posted by smurali on January 9, 2018

We have been using FreeRTOS SW timers all this while for periods ranging from 10ms to 1 minute. Recently we added a timer for 5 minutes. This paritcular timer seems very inaccurate. It usually takes around 5 minutes 45 seconds to trigger the interrupt. Is there something that i am missing?


FreeRTOS SW Timers inaccurate

Posted by rtel on January 9, 2018

Is there something that i am missing?

Don't know, as I don't know what you have.

Which port are you using? Does the chip have a stable and accurate clock? Or is it using a lower accuracy internal resonator? Have you checked the accuracy of the clock and the tick frequency using a scope? Are you setting the tick frequency to something that can be achieved exactly, or are you using a slow low power clock and attempting a tick frequency that can't actually be achieved exactly (considering rounding errors, etc.).

FreeRTOS SW Timers inaccurate

Posted by smurali on January 10, 2018

We are using a port with 64MHz CPU clock which is stable. The configTICKRATEHZ is set 1000

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

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

Latest News

Meet us at Embedded World. Hall 3A-525.

Hear from Richard Barry at Embedded World. Feb 28, 16:00, Hall 4-428.

Video: Watch James Gosling & Richard Barry at re:Invent, Las Vegas 2017.

FreeRTOS kernel V10.0.1 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