Configuring a GPIO pin through overlay

[Omid]

I am wondering If there's any example to demonstrate how I can configure a pin on the nRF52840DK through an overlay.

I have manipulated the board device tree and replaced the LED pin number with one of the DK's pin and I was able to use the pin through the device tree spec apis, in other words,

doing GPIO_DT_SPEC_GET(DT_ALIAS(led0)) and then using gpio_pin_configure_dt() for configuration while I have changed the led0 label in the board's device tree such that it is associated with a different PIN number. I verified it using logic analyzer.

I know that I can also use DEVICE_DT_GET() and gpio_pin_configure() and I am actually doing that for gpio pin configuration in my projects, but I want to learn how I can configure with device tree spec APIs? Is there a way to add an overlay file and do this without the need to manipulate the DK board's device tree file?

Thanks

[AHaug]

Hi,

Yes, there are multiple topics/samples in our academy course that showcases how to modify various board files through overlays to change for instance which GPIO a peripheral should use, for instance modify the led0 node to use LED2 instead of LED1. Among them are lesson 3, exercise 2 in our fundamentals course: https://academy.nordicsemi.com/courses/nrf-connect-sdk-fundamentals/lessons/lesson-3-elements-of-an-nrf-connect-sdk-application/topic/exercise-2/, and Lesson 4, exercise 2 in our intermediate course https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-4-pulse-width-modulation-pwm/ which I've created that also showcases how to modify an existing device and to create your own device using a device binding.

In addition there's the documentation for pin control and how to drive a GPIO pin directly https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/config_and_build/configuring_app/hardware/index.html 

Let me know if this is enough to get you going and if it answers your questions

Kind regards,
Andreas