Flash Write/Read Basic Way

RE: Flash Write/Read Basic Way

superpak — Fri, 13 Oct 2017 18:40:56 GMT

Hi Syuan, I think it is the address that you defined in the NRF_FSTORAGE_DEF macro. Can I see what address you put in there?

RE: Flash Write/Read Basic Way

Syuan — Thu, 12 Oct 2017 06:46:21 GMT

I test the code when run the ret_code_t rc = nrf_fstorage_erase( &m_fs, /* The instance to use. / m_fs.start_addr, / The address of the flash pages to erase. / pages_to_erase, / The number of pages to erase. / NULL); / Optional parameter, backend-dependent. */ it shows Address must be aligned to a page boundary.

Can you help me slove the problem?

RE: Flash Write/Read Basic Way

superpak — Wed, 04 Oct 2017 18:08:59 GMT

Yes, you are correct. But if you are just storing small amounts of data, then FDS can be overkill. However, I just wanted to provide them with this option as well just in case it suits their needs! Thanks!

RE: Flash Write/Read Basic Way

shibshab — Wed, 04 Oct 2017 06:31:52 GMT

Note that garbage collection and other mundane tasks will have to be handled in a live system. FDS makes this a lot simpler for the developer compared to using fstorage directly :)

RE: Flash Write/Read Basic Way

superpak — Tue, 03 Oct 2017 18:45:03 GMT

Hi, you can use Fstorage with the SoftDevice backend for simple read, write and erase operations. Here is a simple example that I wrote. Make sure you have the correct include files. You can change the start_addr and end_addr to any free space you have on your chip. I believe this code should work. This just erases a page and then writes some data in that page. You can read the data using nrf_fstorage_read(....). You can also verify that the data is written by using nrfjprog.

static void fs_event_handler(nrf_fstorage_evt_t * evt){
    if (evt->result != NRF_SUCCESS){
        NRF_LOG_ERROR("Flash error");

    } else {
        NRF_LOG_INFO("Flash event success");
    }
}

NRF_FSTORAGE_DEF(nrf_fstorage_t m_fs) =
{
    .evt_handler = fs_event_handler,
    .start_addr = 0x0007F000,
    .end_addr = 0x000FF000,
};

int main(void){
	uint32_t err_code;
	static uint32_t number = 123;
	static uint32_t pages_to_erase = 1;
	
	err_code = nrf_fstorage_init(&m_fs, &nrf_fstorage_sd, NULL);
    APP_ERROR_CHECK(err_code);

			

				
	ret_code_t rc = nrf_fstorage_erase(
                    &m_fs,   				/* The instance to use. */
                    m_fs.start_addr,     		/* The address of the flash pages to erase. */
                    pages_to_erase, 		/* The number of pages to erase. */
                    NULL);       			/* Optional parameter, backend-dependent. */

	if (rc == NRF_SUCCESS)
	{
			/* The operation was accepted.
				 Upon completion, the NRF_FSTORAGE_ERASE_RESULT event
				is sent to the callback function registered by the instance. */
			
			NRF_LOG_INFO("ERASE SUCCESSFUL");
	}
	else
	{
			NRF_LOG_INFO("ERASE UNSUCCESFUL ");
				/* Handle error.*/
	}



    rc = nrf_fstorage_write(&m_fs, m_fs.start_addr, &number, 4, NULL);      //Write data to memory address. Check it with command: nrfjprog --memrd addr --n 32
	if (rc == NRF_SUCCESS)
	{
		
				NRF_LOG_INFO("WRITE SUCCESSFUL");
	}
	else
	{
			NRF_LOG_INFO("WRITE UNSUCCESFUL ");
				/* Handle error.*/
	}


}

RE: Flash Write/Read Basic Way

shibshab — Tue, 03 Oct 2017 11:01:33 GMT

Updated my answer to include something which actually exists :)

RE: Flash Write/Read Basic Way

Syuan — Tue, 03 Oct 2017 08:56:47 GMT

hi，thanks your answer,but I cant find fds example in examples/peripheral/flash_fds.@@"

RE: Flash Write/Read Basic Way

shibshab — Tue, 03 Oct 2017 08:13:06 GMT

I would use fds.c (short for Flash Data Storage). You can a relative simple use in components/libraries/eddystone/es_flash.c Other examples also use FDS.

Using flash is not trivial, and fds.c (in cooperation with fstorage.c) will hide away all the nasty stuff required to do it correctly.