void fs_evt_handler(nrf_fstorage_evt_t * p_evt)	
{	
		printf("fs_evt_handler\r\n");
}
NRF_FSTORAGE_DEF(nrf_fstorage_t m_instance) =
{
    .evt_handler    = fs_evt_handler,
    .start_addr     = 0xFD000,
    .end_addr       = 0xFFFFF,
};

#define FLASH_ADDR  0xFC000
/* This is the data to write in flash.
   Because the fstorage interface is asynchrounous, the data must be kept in memory.
 */
void write_test(void)
{
		static uint32_t number = 123;
		ret_code_t rc = nrf_fstorage_write(
				&m_instance,   /* The instance to use. */
				FLASH_ADDR,     /* The address in flash where to store the data. */
				&number,        /* A pointer to the data. */
				sizeof(number), /* Lenght of the data, in bytes. */
				NULL            /* Optional parameter, backend-dependent. */
		);
		if (rc == NRF_SUCCESS)
		{
			printf("write OK\r\n");
		}
		else
		{
			printf("write fail\r\n");
		}
}
void read_test(void)
{
		/* This is the data to write in flash.
			 Because the fstorage interface is asynchrounous, the data must be kept in memory.
		 */
		static uint32_t number = 0;
		ret_code_t rc = nrf_fstorage_read(
				&m_instance,   /* The instance to use. */
				FLASH_ADDR,     /* The address in flash where to read data from. */
				&number,        /* A buffer to copy the data into. */
				sizeof(number)  /* Lenght of the data, in bytes. */
		);
		if (rc == NRF_SUCCESS)
		{
				printf("number=%d\r\n",number);
		}
		else
		{
				printf("read fail\r\n");
		}
}
void erase_flash(void)
{
		static uint32_t pages_to_erase = 1;
		ret_code_t rc = nrf_fstorage_erase(
				&m_instance,   /* The instance to use. */
				FLASH_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)
		{
				printf("OK\r\n");
		}
		else
		{
				printf("Erase fail\r\n");
		}
}	
int main()
{
		timers_init();	
    uart_init();
    ble_stack_init();	
	
    nrf_fstorage_init(
        &m_instance,       /* You fstorage instance, previously defined. */
        &nrf_fstorage_sd,   /* Name of the backend. */
        NULL                /* Optional parameter, backend-dependant. */
    );
		erase_flash();
		read_test();	
		write_test();
    read_test();	
}