Turn off and on nrf51dk to test fds with what tool to view output

[jj]

Hi,

I managed to get fds to store some information in nrf51dk for persistent data storage. I would like to check if the data is still available in the chip after power off and on. I have been using SEGGER RTT viewer and Eclipse IDE to compile the code to and run.

Since I will be doing a power off then turn back on, what/how/where can I view the printing output at? Previously I've been running the code from Eclipse IDE with SEGGER RTT at the same time but now that I am turning the chip off first, I'm not sure where can I view the printed output at?

Thank you.

[Sigurd]

Hi,

When you store data to flash using the FDS module, you store your data with a FILE_ID and one or several keys where records are stored. E.g. File 1 with two records: 0x1111="Phone1", 0x2222="data: 12345". Before you store your data you define these IDs and keys:

#define FILE_ID 0x0001 /* The ID of the file to write the records into. */
#define RECORD_KEY_1 0x1111 /* A key for the first record. */
#define RECORD_KEY_2 0x2222 /* A key for the second record. */

When you turn off/on your device, you can use these keys to retrieve the data you stored. This can be done like this:

#define FILE_ID     0x1111
#define RECORD_KEY  0x2222
fds_flash_record_t  flash_record;
fds_record_desc_t   record_desc;
fds_find_token_t    ftok;
/* It is required to zero the token before first use. */
memset(&ftok, 0x00, sizeof(fds_find_token_t));
/* Loop until all records with the given key and file ID have been found. */
while (fds_record_find(FILE_ID, RECORD_KEY, &record_desc, &ftok) == FDS_SUCCESS)
{
    if (fds_record_open(&record_desc, &flash_record) != FDS_SUCCESS)
    {
        /* Handle error. */
    }
    /* Access the record through the flash_record structure. */

    //Here you can print your data with Segger RTT or over UART
    /* Close the record when done. */
    if (fds_record_close(&record_desc) != FDS_SUCCESS)
    {
        /* Handle error. */
    }
}

You can also take a look at how it's done here.

[jj]

Yes I know. What I meant is, how can I check that the data is stored in the fds without having to be running it at the same time with the code? If I were to power off Nordic chip then turn back on, SEGGER RTT will not be able to display the printed output as it did previously when I run the code before it was turn off. So how can I view the printed output after I do a power off then on again?

[Sigurd]

Try to close the Segger RTT viewer, and start it again, and connect with it again. When you re-connect with Segger RTT the output should be printed. Then you can have a function that prints the fds data after fds initialization.