NASR-M board bring-up and Zephyr for a base controller
Zephyr firmware for the base controller is now working. I’ve spent some time setting up a device tree overlay to detect the I2C mux and the underlying devices. It works amazingly! The first thing I did after the firmware compiled initially was a shell module. Actually, it was one of the reasons behind switching to Zephyr. You can access the shell via UART, USB, or even Telnet. It’s extendable with user commands, supports tab completion, and offers many debugger features, such as I2C discovery and memory dumps. Zephyr has many advanced features, such as different schedulers, power management, and an IP stack, but what makes it attractive to me (besides the Apache 2 license) is its extensibility and hundreds of device drivers. It feels like moving away from Borland CRT to Turbovision back in the days. I was able to hook up a temperature sensor via the I2C mux with absolutely no effort. Nice, isn’t it?