RE: FDS not saving variables

zwer97 — Sun, 03 May 2020 13:39:06 GMT

Thanks for your reply! I solved this issue initializing static variable out of write function and now it works. Here is the code

#define FILE_ID     0x1111
#define FILE_KEY     0x2222

static uint32_t data_to_write[3] = {0, 0, 0};

static fds_record_t const m_dummy_record =
{
    .file_id           = FILE_ID,
    .key               = FILE_KEY,
    .data.p_data       = &data_to_write,
    /* The length of a record is always expressed in 4-byte units (words). */
    .data.length_words = (sizeof(data_to_write) + 3) / sizeof(uint32_t),
};

static ret_code_t fds_write_U32()
{
        data_to_write[0] = var1;
        data_to_write[1] = var2;
        data_to_write[2] = var3;
        
		fds_record_desc_t   record_desc;
                				
		ret_code_t ret = fds_record_write(&record_desc, &m_dummy_record);
		if (ret != NRF_SUCCESS)
		{
				return ret;
		}
		NRF_LOG_INFO("Writing Record ID = %d \r\n",record_desc.record_id);
		return NRF_SUCCESS;
}

RE: FDS not saving variables

Turbo J — Sun, 03 May 2020 08:46:16 GMT

How do you read the records?

When fds_record_write() was called twice, you will end up whith two identical (in id and key) records with possibly different data.

That is why there is a fds_record_update() function...

Edit: Your m_data[] buffer must not be on the stack, as fds_record_write() is a function with delayed execution (using softdevice). Due to m_data being on the stack it will be overwritten by the time the softdevice actually writes to flash.