Use GPIO from Arduino Header using Zephyr on nrf52840DK

[geopen]

Hello,

I am new here and I hope to not duplicate any other similar post (to be honest I have search a lot before writing).

I am working with nrf52840DK, I have used blinky Zephyr example successfully.

I would like to use one of the GPIOs from the arduino_header: connector.
I see in the device tree (.dts file), that there is the definition of it as following:

	arduino_header: connector {
		compatible = "arduino-header-r3";
		#gpio-cells = <2>;
		gpio-map-mask = <0xffffffff 0xffffffc0>;
		gpio-map-pass-thru = <0 0x3f>;
		gpio-map = <0 0 &gpio0 04 0>,	/* A0 */
			   <1 0 &gpio0 30 0>,	/* A1 */
			   <2 0 &gpio0 5 0>,	/* A2 */
			   <3 0 &gpio0 2 0>,	/* A3 */
			   <4 0 &gpio0 28 0>,	/* A4 */
			   <5 0 &gpio0 3 0>,	/* A5 */
			   <6 0 &gpio0 29 0>,	/* D0 */
			   <7 0 &gpio1 13 0>,	/* D1 */
			   <8 0 &gpio1 12 0>,	/* D2 */
			   <9 0 &gpio0 31 0>,	/* D3 */
			   <10 0 &gpio0 13 0>,	/* D4 */
			   <11 0 &gpio0 11 0>,	/* D5 */
			   <12 0 &gpio0 9 0>,	/* D6 */
			   <13 0 &gpio0 10 0>,	/* D7 */
			   <14 0 &gpio1 9 0>,	/* D8 */
			   <15 0 &gpio0 12 0>,	/* D9 */
			   <16 0 &gpio0 14 0>,	/* D10 */
			   <17 0 &gpio0 15 0>,	/* D11 */
			   <18 0 &gpio1 0 0>,	/* D12 */
			   <19 0 &gpio0 7 0>,	/* D13 */
			   <20 0 &gpio0 16 0>,	/* D14 */
			   <21 0 &gpio0 24 0>;	/* D15 */
	};

But how can I use it in my main.c ? Is there any example for it?

Many thanks,
George

[btemesi]

Hi,

When you are defining a new node, you can use the gpio-map such as:

`<&arduino_header 16 GPIO_ACTIVE_LOW>;`

Where, 16 is the list number followed by the flag(s). I wouldn't re-define it (so no &gpio0 4).

You can find more documentation here:

https://docs.zephyrproject.org/latest/hardware/porting/shields.html

which also points to documentation:

github.com/.../devicetree-basics.rst

and an example here:

<your-sdk-location>/<sdk-version>/zephyr/samples/sensor/bme280/arduino_spi.overlay

This is a similar sensor (BME280) example as in the dev Academy - nrf Connect SDK Fundamentals

I hope this helps,

Barna