Cant change registers via pionters on nrf53

RE: Cant change registers via pionters on nrf53

TiNy — Sun, 08 Aug 2021 21:23:44 GMT

Thank for your answer and advice. It work exactly how you say.

RE: Cant change registers via pionters on nrf53

Carl Richard — Thu, 29 Jul 2021 08:41:14 GMT

Hello again!

Apologies for the delayed answer here. I reached out to some colleagues and they pointed out a mistake in your code. When you deal with pointer types the arithmetic take the pointer type into account. As an example, if you have a pointer to an array of uint32_t, and you want to access the next element in the array you have to increase the pointer by 4. In this case this means that your gpio_out_clr and gpio_dir_set pointers end up with the wrong value. This can be fixed by casting gpio_base to and int before doing the addition. Like this:

volatile uint32_t *gpio_base = (uint32_t *) 0x50842500UL;
volatile uint32_t *gpio_out_clr = (uint32_t *) ((int)gpio_base + 0x00CUL);
volatile uint32_t *gpio_dir_set = (uint32_t *) ((int)gpio_base + 0x018UL);

*gpio_dir_set = 0xf0180000UL;
*gpio_out_clr = 0x00180000UL;

By the way, one of the developers pointed out that you can use the standalone nRFX driver set as a starting point, instead of implementing your own HAL.

Best regards,
Carl Richard

RE: Cant change registers via pionters on nrf53

TiNy — Fri, 16 Jul 2021 14:12:19 GMT

Thanks for response. I'll wait you.

RE: Cant change registers via pionters on nrf53

Carl Richard — Fri, 16 Jul 2021 14:10:05 GMT

Interesting. The SPU should not affect anything unless you're building for nrf5340dk_nrf5340_cpuappns, but if that's not the case I need to do some more investigation.

Will get back to you over the weekend! Thank you for your patience.

Best regards,
Carl Richard

RE: Cant change registers via pionters on nrf53

TiNy — Fri, 16 Jul 2021 14:01:12 GMT

nrf5340dk_nrf5340_cpuapp

RE: Cant change registers via pionters on nrf53

Carl Richard — Fri, 16 Jul 2021 13:54:43 GMT

Which board are you targeting when building for the nRF Connect SDK?

Best regards,
Carl Richard

RE: Cant change registers via pionters on nrf53

TiNy — Fri, 16 Jul 2021 13:50:28 GMT

oh, I see, thanks for link, but I still confused whats exactly wrong with code above? Why when I setup registers via set command at gdb its work fine, but when i do same setup from C code in nrfconnect sdk, its not work?

RE: Cant change registers via pionters on nrf53

Carl Richard — Fri, 16 Jul 2021 12:55:14 GMT

Hello!

There already exists some Rust crates for nRF53. I suggest trying out those. If you are facing issues with the crates or wonder about their usage please reach out to the Rust embedded working group as they probably can provide better help than us.

Best regards,
Carl Richard