Read current value of an OUTPUT gpio pin

[Pedro]

Hi!

Any way in Zephyr to read the current value of a GPIO pin that is configured as OUTPUT?

Thanks!

Pedro.

[Einar Thorsrud]

Hi,

You can use nrf_gpio_pin_out_read() to read the state of an output pin in the OUT register.

[Pedro]

Hi Einar,

I'm using NCS v2.0.2, with Zephyr, so I use gpio_pin_get(). The problem is when GPIO is configured as output, I can not use this function to read its current value.

How can I do this?

Thanks and kind regards,

Pedro.

[Einar Thorsrud]

Hi Pedro,

You are right, gpio_pin_get() can only be used to read an input pin. That is why I suggested that you use nrf_gpio_pin_out_read() , which is for reading the state of an output pin

[Pedro]

But, how can I use nrf_gpio_pin_out_read() with NCS v2.0.2, with Zephyr? Isn't it a function of the old Nordic SDK?

[Einar Thorsrud]

It is a low-level function from nrfx that is available regardless of which SDK you are using. It exist in NCS v2.0.2, and also in the latest v2.4.2.

[Pedro]

Ah, I see.

I've found this function in C:\ncs\v2.0.2\modules\hal\nordic\nrfx\hal\nrf_gpio.h

But, how can I include it in my project?

If I try #include <modules/hal/nordic/nrfx/hal/nrf_gpio.h> it does not find the file.

I do not understand the include paths when using NCS. They do not correspond exactly with file system folder structure.

Thanks again!

Pedro.

[Einar Thorsrud]

Hi Pedro,

You should include it like this:

#include <hal/nrf_gpio.h>

[Pedro]

Thanks Einar!

How can I find in the future the include path for other .h files? They do not correspond with the system folder structure.