a44df5c1b9
Issue The existing clock discipline algorithm in the coreSNTP demo yields an inaccurate wall-clock time (in UTC) that is always behind the astronomical UTC time by the chosen polling interval period of the demo. The issue with the clock discipline algorithm was that it was calculating the slew rate to make the system clock be gradually compensated for the previous time synchronization clock drift over the period of the subsequent polling time interval. Thereby, the clock slew rate correction calculated is always lower than it should be (because it does not incorporate possible clock drift that would occur over another period of time polling interval till the next time synchronization attempt). Fix This PR fixes the clock discipline algorithm to make the demo calculate its system time that matches the astronomical UTC time. The fix involves simplifying the clock discipline algorithm to use a combination of step and slew correction approaches where: 1. Step correction is applied on EVERY time successful synchronization with a time server. This immediately corrects the system time to match server time. 2. Slew rate is calculated ONCE (on the second successful time synchronization with server) and applied henceforth, on every time polling interval period to compensate gradually for the system clock drift during the period.
The FreeRTOS 202104.00 release introduces the new coreMQTT Agent library, and includes all the Long-Term Support (LTS) libraries that are part of the FreeRTOS-LTS 202012.01-LTS release. Learn more about the FreeRTOS 202012.01 LTS libraries at https://freertos.org/lts-libraries.html.
Getting started
The FreeRTOS.org website contains a FreeRTOS Kernel Quick Start Guide, a list of supported devices and compilers, the API reference, and many other resources.
Getting help
You can use your Github login to get support from both the FreeRTOS community and directly from the primary FreeRTOS developers on our active support forum. The FAQ provides another support resource.
Cloning this repository
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Repository structure
This repository contains the FreeRTOS Kernel, a number of supplementary libraries including the LTS ones, and a comprehensive set of example projects. Many libraries (including the FreeRTOS kernel) are included as Git submodules from their own Git repositories.
Kernel source code and example projects
FreeRTOS/Source contains the FreeRTOS kernel source code (submoduled from https://github.com/FreeRTOS/FreeRTOS-Kernel).
FreeRTOS/Demo contains pre-configured example projects that demonstrate the FreeRTOS kernel executing on different hardware platforms and using different compilers.
Supplementary library source code and example projects
FreeRTOS-Plus/Source contains source code for additional FreeRTOS component libraries, as well as select partner provided libraries. These subdirectories contain further readme files and links to documentation.
FreeRTOS-Plus/Demo contains pre-configured example projects that demonstrate the FreeRTOS kernel used with the additional FreeRTOS component libraries.
Previous releases
Releases contains older FreeRTOS releases.
FreeRTOS Lab Projects
FreeRTOS Lab projects are libraries and demos that are fully functional, but may be experimental or undergoing optimizations and refactorization to improve memory usage, modularity, documentation, demo usability, or test coverage.
Most FreeRTOS Lab libraries can be found in the FreeRTOS-Labs repository.
A number of FreeRTOS Lab Demos can be found in the FreeRTOS Github Organization by searching for "Lab" or following this link to the search results.
coreMQTT Agent Demos
The FreeRTOS/coreMQTT-Agent-Demos repository contains demos to showcase use of the coreMQTT-Agent library to share an MQTT connection between multiple application tasks.
The demos show a single MQTT connection usage between multiple application tasks for interacting with AWS services (including Over-the-air-Updates, Device Shadow, Device Defender) alongside performing simple Publish-Subscribe operations.