Introduction to Zephyr Part 9: Interrupts, Timers, and Counters | DigiKey

Video Description

In this video, we explore interrupts, timers, counters in Zephyr RTOS. Interrupts are a cornerstone of embedded development, enabling systems to respond instantly to external or internal events. We’ll break down how interrupts work, the importance of efficient Interrupt Service Routines (ISRs), and how to handle time-sensitive operations without compromising performance. You can find a written explanation of these concepts and a breakdown of the challenge solution here: https://www.digikey.com/en/maker/tutorials/2025/introduction-to-zephyr-part-9-interrupts-and-workqueues The GitHub repository for this course (including solutions to the challenges) can be found here: https://github.com/ShawnHymel/introduction-to-zephyr/tree/main Timers and counters are key tools in Zephyr for managing time-driven tasks. We’ll compare software-based timers, which rely on the kernel’s internal clock, to hardware-based counters that offer microsecond or nanosecond precision. By understanding when to use each, you’ll gain the ability to design systems that balance precision with flexibility. The video also dives into GPIO interrupts, showcasing how to configure them for external events like button presses. We’ll address common challenges, such as button debounce, and demonstrate practical solutions to ensure your system processes input reliably, even under noisy conditions. Workqueues are another powerful feature in Zephyr, allowing you to defer complex operations from ISRs to thread-based contexts. This not only keeps your ISRs lightweight but also ensures that tasks requiring more resources can be executed safely and efficiently. By the end of this video, you’ll understand how to leverage workqueues to enhance system responsiveness while maintaining robust functionality. This tutorial is perfect for embedded developers and enthusiasts looking to deepen their understanding of Zephyr RTOS. With clear explanations and practical examples, it provides the knowledge you need to build efficient, real-time applications, whether you’re working on IoT devices, motor control systems, or edge AI projects. Official Zephyr documentation: https://docs.zephyrproject.org/latest/index.html Introduction to RTOS: https://www.youtube.com/watch?v=F321087yYy4&list=PLEBQazB0HUyQ4hAPU1cJED6t3DU0h34bz ESP32-S3-DevKitC: https://www.digikey.com/en/products/detail/espressif-systems/ESP32-S3-DEVKITC-1-N32R8V/15970965 Maker.io - https://www.digikey.com/en/maker DigiKey’s Blog – TheCircuit https://www.digikey.com/en/blog Connect with DigiKey on Facebook https://www.facebook.com/digikey.electronics/ And follow us on X: https://x.com/digikey 0:00 Intro 0:46 Overview of Timers 1:36 Develop Timer Demo 6:49 Run Timer Demo 8:11 Overview of Zephyr Counters 9:36 ESP32 Interrupts and Counters 15:29 Overview ESP32 Interrupts and Counters in the Devicetree 23:16 Develop Counter Interrupt Demo 39:37 Run Counter Interrupt Demo 40:14 Overview of Pin Change Interrupts 43:03 Develop Pin Change Interrupt Demo 51:03 Run Pin Change Interrupt Demo 52:05 Challenge: Work Queues 55:06 Conclusion