Software Timers
[More about software timers…]

Resetting a software timer

It is possible to re-set a timer that has already started to run. Resetting a timer results in the timer recalculating its expiry time so the expiry time becomes relative to when the timer was reset, and not when the timer was originally started. This behaviour is demonstrated in the next diagram, where Timer 1 is a one-shot timer that has a period equal to 5 seconds.

In the depicted example, it is assumed that the application switches on an LCD back-light when a key is pressed, and that the back-light remains on until 5 seconds pass without any keys being pressed. Timer 1 is used to switch off the LCD back-light when this 5 seconds has elapsed.

The behaviour of one-shot timers and auto-reload timers
Timer behaviour when a timer is reset




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.

New Updates to MIT licensed IoT MQTT and POSIX libraries are now available. New library IoT HTTPS is available.  Includes demo projects.

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

Careers

FreeRTOS and other embedded software careers at AWS.

FreeRTOS Partners
ARM Connected RTOS partner for all ARM microcontroller cores
Espressif ESP32
IAR Partner
Microchip Premier RTOS Partner
Renesas
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