How To Use Zephyr Overlays

This article is part of TechXchange: RTOS: Zephyr Project

The Zephyr Project is a compact RTOS designed for resource constrained systems. This video highlights the use of code overlays. These allow customization of firmware images for particular hardware targets. For instance, we might use the "device tree overlay" to change which pin we are targeting for a signal assigned to LED0. In this particular example, we are showing how to change the pins for the ESP32 demo.

This is a further explanation of the device tree overlay shown in the LightDB Demo Videos: Part 1 and LightDB Demo Videos: Part 2.

Fast Forward

• 0:00 Introduction
• 0:45 2 types of Zephyr overlays
• 2:15 Configuring a GPIO using an device overlay
• 4:00 LightDB example on ESP32 6:30 Looking at a configuration overlay
• 8:00 Tweaking memory and enabling libraries
• 10:30 Where to look in Zephyr directories
• 13:15 Connecting LEDs to pins
• 15:10 The difficulties of porting between boards/chips (before Zephyr)
• 19:15 Reviewing source code
• 23:10 Extending the idea to other GPIO examples
• 24:00 Conclusion