fs_store data lost after power off

[Kapil Rawat]

Hi

I'm using fs_storage function to read and write in flash memory. Value successfully stored in evt->store.p_data but after power off it value become 0

switch(evt->id)
    {
        case FS_EVT_STORE:
            if(result == FS_SUCCESS)
            {
                stored_data = evt->store.p_data;
            }
    }

I'm using sdk11 with nrf528122.

[Hung Bui]

Could you post a snippet of your code? Which address did you write ? If you try to read the value at that address (before power reset) do you see the data or it's just 0 ? I assume you wait for FS_EVT_STORE - FS_SUCCESS before you do power reset.

Could you explain what you want to do with the line: stored_data = evt->store.p_data; ?

[Kapil Rawat]

Yes before reset I can see data

below code is used for retrieve data from the fs_evt_handler

stored_data = evt->store.p_data;

I'm following this info infocenter.nordicsemi.com/index.jsp

[emdi]

Could you provide a snippet of your code, specifically how you try to read the data after a reset?

[Hung Bui]

@Kapil: Please try to read data from the flash. Note that after you reset, there will be no data in neither evt->store.p_data nor stored_data as they are variable in RAM not flash.

[Kapil Rawat]

Here is my code snippet

//flash storage handler 
static void fs_evt_handler(fs_evt_t const * const evt, fs_ret_t result)
{
    switch(evt->id)
    {
        case FS_EVT_STORE:
            if(result == FS_SUCCESS)
            {
                stored_data = evt->store.p_data;
	        SEGGER_RTT_printf(0,"\n evt_stored_data : %x",*stored_data );
            }
            break;

        case FS_EVT_ERASE:
            // Handle erase event
            break;

        default:
            //Do nothing
				           
            break;

    }
}

//Flash config
     FS_REGISTER_CFG(fs_config_t fs_config) =
     {
		.callback  = fs_evt_handler,    // Function for event callbacks.
		.num_pages = 1,                 // Number of physical flash pages required.
		.priority  = 0xFE               // Priority for flash usage.
     };

//flash store 
  ret = fs_store(&fs_config, fs_config.p_start_addr, &f_data, 1);
  fs_ret_t ret = fs_init();						//Flash storage init

//For reading data from flash I'm calling same function and try to access data from *stored_data pointer (without erasing this will give me last value stored in flash)

{
		ret = fs_store(&fs_config, fs_config.p_start_addr, &f_data, 1);
		SEGGER_RTT_printf(0,"\n Main evt_Flash_Data stored : %d",*stored_data );
            f_data= *stored_data;
}