Control peripherals (nRF52840 and Zephyr)

[witc]

Hi,

I am a novice in the Nordic world. I have to say it is really new conception for me. I am used to work with STM32 and freeRTOS.

If I understand corectly, when I want to control any of peripherals (like  TIMER, SPI, UART,..)  it is controlled via Zephyr API? E.g. in product spec. of nRF52840 are registers called like some tasks?   It means all peripherals are like some software tasks, or just only "unusal" name of registers is confusing me and still it is "normal" hardware peripherals?

When I want to work with e.g. hardware timer, should I go there: https://docs.zephyrproject.org/3.1.0/hardware/peripherals/counter.html and use these API? Is that what I need, or it is not best practice?

Thank you for now.

[Didrik Rokhaug]

Hi,

It means all peripherals are like some software tasks, or just only "unusal" name of registers is confusing me and still it is "normal" hardware peripherals?

The TASKS_* registers are used for PPI: https://infocenter.nordicsemi.com/topic/ps_nrf52840/ppi.html

It has nothing to do with RTOS tasks.

However, while you can control the peripherals via the registers directly, I recommend using a driver instead. There are several layers of drivers, where each layer generally trades fine control versus convenience.

We have a NCS fundamentals course which amongst other things covers how to use Zephyr's drivers (which is generally the recommended approach): https://academy.nordicsemi.com/courses/nrf-connect-sdk-fundamentals/

We also have an older guide (it was written for NCS v1.5.0), which goes deeper into some of the details of NCS, including the drivers:  nRF Connect SDK Tutorial series - Part 0 | NCS v1.5.0

There has been a lot of changes in NCS since v1.5.0, so don't expect all the details and examples to work in the newer versions, but the general ideas and concepts should still be applicable.

Best regards,

Didrik