Messing around with Zephyr

Attempt to flash an LED on the rpi_pico using led_blink API, not raw GPIO+Delay

How this works

• The rpi_pico device tree already contains a GPIO LED instance, but unused.

• Enable GPIO, LED and GPIO_LED Kconfig options in prj.conf

CONFIG_GPIO=y
CONFIG_LED=y
CONFIG_LED_GPIO=y

Hence the LED_GPIO driver will be built in, rather than expose the led as just a GPIO

• Get the parent of the led0 alias and use this to control it.

• Hardcode back that we want to access the first LED (0), as getting this from devicetree is a bit tricky. See zephyrproject-rtos/zephyr#42015

• Try and use led_blink, but this is not implemented for the led-gpio driver, it was split into a separate KConfig option in an earlier pull request then abandoned.

• Then uses software timers instead, which is easier.

How to load code

Hold the boot switch and replug USB copy build/zephyr/zephyr.uf2 to your rpi_pico