fstorage read a int or float from flash

[melt]

Goodday

I have integrated the fstorage peripheral  example with the BLE_beaconing example. SDK 15.2. I can read and write strings. I cannot read back the hex number if declared as an int or a float

my problem lies in how to use this function to read a float or int.

 rc = nrf_fstorage_read(&fstorage, 0x3e100, &m_data_read,sizeof(m_data_read));

My Main.c code below

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/** @file
 *
 * @defgroup ble_sdk_app_beacon_main main.c
 * @{
 * @ingroup ble_sdk_app_beacon
 * @brief Beacon Transmitter Sample Application main file.
 *
 * This file contains the source code for an Beacon transmitter sample application.
 */

#include <stdbool.h>
#include <stdint.h>
#include "nordic_common.h"
#include "bsp.h"
#include "nrf_soc.h"
#include "nrf_sdh.h"
#include "nrf_sdh_ble.h"
#include "ble_advdata.h"
#include "app_timer.h"
#include "nrf_pwr_mgmt.h"

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "nrf_fstorage_sd.h"

#ifdef SOFTDEVICE_PRESENT
#include "nrf_sdh.h"
#include "nrf_sdh_ble.h"
#include "nrf_fstorage_sd.h"
#else
#include "nrf_drv_clock.h"
#include "nrf_fstorage_nvmc.h"
#endif
#define APP_BLE_CONN_CFG_TAG            1                                  /**< A tag identifying the SoftDevice BLE configuration. */

#define NON_CONNECTABLE_ADV_INTERVAL    MSEC_TO_UNITS(100, UNIT_0_625_MS)  /**< The advertising interval for non-connectable advertisement (100 ms). This value can vary between 100ms to 10.24s). */

#define APP_BEACON_INFO_LENGTH          0x17                               /**< Total length of information advertised by the Beacon. */
#define APP_ADV_DATA_LENGTH             0x15                               /**< Length of manufacturer specific data in the advertisement. */
#define APP_DEVICE_TYPE                 0x02                               /**< 0x02 refers to Beacon. */
#define APP_MEASURED_RSSI               0xC3                               /**< The Beacon's measured RSSI at 1 meter distance in dBm. */
#define APP_COMPANY_IDENTIFIER          0x0059                             /**< Company identifier for Nordic Semiconductor ASA. as per www.bluetooth.org. */
#define APP_MAJOR_VALUE                 0x01, 0x02                         /**< Major value used to identify Beacons. */
#define APP_MINOR_VALUE                 0x03, 0x04                         /**< Minor value used to identify Beacons. */
#define APP_BEACON_UUID                 0x01, 0x12, 0x23, 0x34, \
                                        0x45, 0x56, 0x67, 0x78, \
                                        0x89, 0x9a, 0xab, 0xbc, \
                                        0xcd, 0xde, 0xef, 0xf0            /**< Proprietary UUID for Beacon. */


#define DEAD_BEEF                       0xDEADBEEF                         /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */

#if defined(USE_UICR_FOR_MAJ_MIN_VALUES)
#define MAJ_VAL_OFFSET_IN_BEACON_INFO   18                                 /**< Position of the MSB of the Major Value in m_beacon_info array. */
#define UICR_ADDRESS                    0x10001080                         /**< Address of the UICR register used by this example. The major and minor versions to be encoded into the advertising data will be picked up from this location. */
#endif

static ble_gap_adv_params_t m_adv_params;                                  /**< Parameters to be passed to the stack when starting advertising. */
static uint8_t              m_adv_handle = BLE_GAP_ADV_SET_HANDLE_NOT_SET; /**< Advertising handle used to identify an advertising set. */
static uint8_t              m_enc_advdata[BLE_GAP_ADV_SET_DATA_SIZE_MAX];  /**< Buffer for storing an encoded advertising set. */


static void fstorage_evt_handler(nrf_fstorage_evt_t * p_evt);

NRF_FSTORAGE_DEF(nrf_fstorage_t fstorage) =
{
    /* Set a handler for fstorage events. */
    .evt_handler = fstorage_evt_handler,

    /* These below are the boundaries of the flash space assigned to this instance of fstorage.
     * You must set these manually, even at runtime, before nrf_fstorage_init() is called.
     * The function nrf5_flash_end_addr_get() can be used to retrieve the last address on the
     * last page of flash available to write data. */
    .start_addr = 0x3e000,
    .end_addr   = 0x3ffff,
};

/* Dummy data to write to flash. */
const uint32_t m_data          = 123456;
const uint32_t m_data_read  ; // used to store the read back from flash


char     m_hello_world[12] = "hello world";
char     m_hello_world_read[12]="\0"; // used to store the read back from flash




/**@brief   Helper function to obtain the last address on the last page of the on-chip flash that
 *          can be used to write user data.
 */
static uint32_t nrf5_flash_end_addr_get()
{
    uint32_t const bootloader_addr = NRF_UICR->NRFFW[0];
    uint32_t const page_sz         = NRF_FICR->CODEPAGESIZE;
    uint32_t const code_sz         = NRF_FICR->CODESIZE;

    return (bootloader_addr != 0xFFFFFFFF ?
            bootloader_addr : (code_sz * page_sz));
}




/**@brief Struct that contains pointers to the encoded advertising data. */
static ble_gap_adv_data_t m_adv_data =
{
    .adv_data =
    {
        .p_data = m_enc_advdata,
        .len    = BLE_GAP_ADV_SET_DATA_SIZE_MAX
    },
    .scan_rsp_data =
    {
        .p_data = NULL,
        .len    = 0

    }
};


static uint8_t m_beacon_info[APP_BEACON_INFO_LENGTH] =                    /**< Information advertised by the Beacon. */
{
    APP_DEVICE_TYPE,     // Manufacturer specific information. Specifies the device type in this
                         // implementation.
    APP_ADV_DATA_LENGTH, // Manufacturer specific information. Specifies the length of the
                         // manufacturer specific data in this implementation.
    APP_BEACON_UUID,     // 128 bit UUID value.
    APP_MAJOR_VALUE,     // Major arbitrary value that can be used to distinguish between Beacons.
    APP_MINOR_VALUE,     // Minor arbitrary value that can be used to distinguish between Beacons.
    APP_MEASURED_RSSI    // Manufacturer specific information. The Beacon's measured TX power in
                         // this implementation.
};


/**@brief Callback function for asserts in the SoftDevice.
 *
 * @details This function will be called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and does not fit a final product. You need to analyze
 *          how your product is supposed to react in case of Assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in]   line_num   Line number of the failing ASSERT call.
 * @param[in]   file_name  File name of the failing ASSERT call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
{
    app_error_handler(DEAD_BEEF, line_num, p_file_name);
}

/**@brief Function for initializing the Advertising functionality.
 *
 * @details Encodes the required advertising data and passes it to the stack.
 *          Also builds a structure to be passed to the stack when starting advertising.
 */
static void advertising_init(void)
{
    uint32_t      err_code;
    ble_advdata_t advdata;
    uint8_t       flags = BLE_GAP_ADV_FLAG_BR_EDR_NOT_SUPPORTED;

    ble_advdata_manuf_data_t manuf_specific_data;

    manuf_specific_data.company_identifier = APP_COMPANY_IDENTIFIER;

#if defined(USE_UICR_FOR_MAJ_MIN_VALUES)
    // If USE_UICR_FOR_MAJ_MIN_VALUES is defined, the major and minor values will be read from the
    // UICR instead of using the default values. The major and minor values obtained from the UICR
    // are encoded into advertising data in big endian order (MSB First).
    // To set the UICR used by this example to a desired value, write to the address 0x10001080
    // using the nrfjprog tool. The command to be used is as follows.
    // nrfjprog --snr <Segger-chip-Serial-Number> --memwr 0x10001080 --val <your major/minor value>
    // For example, for a major value and minor value of 0xabcd and 0x0102 respectively, the
    // the following command should be used.
    // nrfjprog --snr <Segger-chip-Serial-Number> --memwr 0x10001080 --val 0xabcd0102
    uint16_t major_value = ((*(uint32_t *)UICR_ADDRESS) & 0xFFFF0000) >> 16;
    uint16_t minor_value = ((*(uint32_t *)UICR_ADDRESS) & 0x0000FFFF);

    uint8_t index = MAJ_VAL_OFFSET_IN_BEACON_INFO;

    m_beacon_info[index++] = MSB_16(major_value);
    m_beacon_info[index++] = LSB_16(major_value);

    m_beacon_info[index++] = MSB_16(minor_value);
    m_beacon_info[index++] = LSB_16(minor_value);
#endif

    manuf_specific_data.data.p_data = (uint8_t *) m_beacon_info;
    manuf_specific_data.data.size   = APP_BEACON_INFO_LENGTH;

    // Build and set advertising data.
    memset(&advdata, 0, sizeof(advdata));

    advdata.name_type             = BLE_ADVDATA_NO_NAME;
    advdata.flags                 = flags;
    advdata.p_manuf_specific_data = &manuf_specific_data;

    // Initialize advertising parameters (used when starting advertising).
    memset(&m_adv_params, 0, sizeof(m_adv_params));

    m_adv_params.properties.type = BLE_GAP_ADV_TYPE_NONCONNECTABLE_NONSCANNABLE_UNDIRECTED;
    m_adv_params.p_peer_addr     = NULL;    // Undirected advertisement.
    m_adv_params.filter_policy   = BLE_GAP_ADV_FP_ANY;
    m_adv_params.interval        = NON_CONNECTABLE_ADV_INTERVAL;
    m_adv_params.duration        = 0;       // Never time out.

    err_code = ble_advdata_encode(&advdata, m_adv_data.adv_data.p_data, &m_adv_data.adv_data.len);
    APP_ERROR_CHECK(err_code);

    err_code = sd_ble_gap_adv_set_configure(&m_adv_handle, &m_adv_data, &m_adv_params);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for starting advertising.
 */
static void advertising_start(void)
{
    ret_code_t err_code;

    err_code = sd_ble_gap_adv_start(m_adv_handle, APP_BLE_CONN_CFG_TAG);
    APP_ERROR_CHECK(err_code);

    err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupt.
 */
static void ble_stack_init(void)
{
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);
}


static void fstorage_evt_handler(nrf_fstorage_evt_t * p_evt)
{
    if (p_evt->result != NRF_SUCCESS)
    {
        NRF_LOG_INFO("--> Event received: ERROR while executing an fstorage operation.");
        return;
    }

    switch (p_evt->id)
    {
        case NRF_FSTORAGE_EVT_WRITE_RESULT:
        {
            NRF_LOG_INFO("--> Event received: wrote %d bytes at address 0x%x.",
                         p_evt->len, p_evt->addr);
        } break;

        case NRF_FSTORAGE_EVT_ERASE_RESULT:
        {
            NRF_LOG_INFO("--> Event received: erased %d page from address 0x%x.",
                         p_evt->len, p_evt->addr);
        } break;

        default:
            break;
    }
}


/**@brief   Sleep until an event is received. */
static void power_manage(void)
{
#ifdef SOFTDEVICE_PRESENT
    (void) sd_app_evt_wait();
#else
    __WFE();
#endif
}


static void print_flash_info(nrf_fstorage_t * p_fstorage)
{
    NRF_LOG_INFO("========| flash info |========");
    NRF_LOG_INFO("erase unit: \t%d bytes",      p_fstorage->p_flash_info->erase_unit);
    NRF_LOG_INFO("program unit: \t%d bytes",    p_fstorage->p_flash_info->program_unit);
    NRF_LOG_INFO("==============================");
}


void wait_for_flash_ready(nrf_fstorage_t const * p_fstorage)
{
    /* While fstorage is busy, sleep and wait for an event. */
    while (nrf_fstorage_is_busy(p_fstorage))
    {
        power_manage();
    }
}




/**@brief Function for initializing logging. */
static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}

/**@brief Function for initializing LEDs. */
static void leds_init(void)
{
    ret_code_t err_code = bsp_init(BSP_INIT_LEDS, NULL);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing timers. */
static void timers_init(void)
{
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing power management.
 */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop).
 *
 * @details If there is no pending log operation, then sleep until next the next event occurs.
 */
static void idle_state_handle(void)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}


/** as per example but 
 * @brief Function for application main entry.
 */
int main(void)
{
   ret_code_t rc = NRF_LOG_INIT(NULL);

    // Initialize.
    log_init();
    timers_init();
    leds_init();
    power_management_init();
    ble_stack_init();
    advertising_init();

    // Start execution.
    NRF_LOG_INFO("Beacon example started.");
    advertising_start();

     nrf_fstorage_api_t * p_fs_api;

#ifdef SOFTDEVICE_PRESENT
    NRF_LOG_INFO("SoftDevice is present.");
    NRF_LOG_INFO("Initializing nrf_fstorage_sd implementation...");
    /* Initialize an fstorage instance using the nrf_fstorage_sd backend.
     * nrf_fstorage_sd uses the SoftDevice to write to flash. This implementation can safely be
     * used whenever there is a SoftDevice, regardless of its status (enabled/disabled). */
    p_fs_api = &nrf_fstorage_sd;
#else
    NRF_LOG_INFO("SoftDevice not present.");
    NRF_LOG_INFO("Initializing nrf_fstorage_nvmc implementation...");
    /* Initialize an fstorage instance using the nrf_fstorage_nvmc backend.
     * nrf_fstorage_nvmc uses the NVMC peripheral. This implementation can be used when the
     * SoftDevice is disabled or not present.
     *
     * Using this implementation when the SoftDevice is enabled results in a hardfault. */
    p_fs_api = &nrf_fstorage_nvmc;
#endif

    rc = nrf_fstorage_init(&fstorage, p_fs_api, NULL);
    APP_ERROR_CHECK(rc);

    print_flash_info(&fstorage);

    /* It is possible to set the start and end addresses of an fstorage instance at runtime.
     * They can be set multiple times, should it be needed. The helper function below can
     * be used to determine the last address on the last page of flash memory available to
     * store data. */
    (void) nrf5_flash_end_addr_get();

    /* Let's write to flash. */
    NRF_LOG_INFO("Writing \"%x\" to flash.", m_data);
    rc = nrf_fstorage_write(&fstorage, 0x3e000, &m_data, sizeof(m_data), NULL);
    APP_ERROR_CHECK(rc);

    wait_for_flash_ready(&fstorage);
    NRF_LOG_INFO("Done.");

#ifdef SOFTDEVICE_PRESENT
    // Enable the SoftDevice and the BLE stack. 
    NRF_LOG_INFO("Enabling the SoftDevice.");
//    ble_stack_init();

 //   m_data = 0xDEADBEEF;

    NRF_LOG_INFO("Writing \"%x\" to flash.", m_data);
    rc = nrf_fstorage_write(&fstorage, 0x3e100, &m_data, sizeof(m_data), NULL);
    APP_ERROR_CHECK(rc);

    wait_for_flash_ready(&fstorage);
    NRF_LOG_INFO("Done.");
#endif

    NRF_LOG_INFO("Writing \"%s\" to flash.", m_hello_world);
    rc = nrf_fstorage_write(&fstorage, 0x3f000, m_hello_world, sizeof(m_hello_world), NULL);
    APP_ERROR_CHECK(rc);

    wait_for_flash_ready(&fstorage);
    NRF_LOG_INFO("Done.");



    rc = nrf_fstorage_read(&fstorage, 0x3f000, m_hello_world_read, sizeof(m_hello_world_read));
    APP_ERROR_CHECK(rc);
    NRF_LOG_INFO("Reading \"%s\" from flash.", m_hello_world_read);


    wait_for_flash_ready(&fstorage);
    NRF_LOG_INFO("Done.");


    rc = nrf_fstorage_read(&fstorage, 0x3e100, &m_data_read,sizeof(m_data_read));
    APP_ERROR_CHECK(rc);
    NRF_LOG_INFO("Reading \"%s\" from flash.", m_data_read);





    // Enter main loop.
    for (;; )
    {
        idle_state_handle();
    }
}


/**
 * @}
 */

[Kenneth]

Hi,

Haven't tested the code, but a few things to try:

1. I notice you have declared m_data_read as const, not sure if that will work here.

2. I assume you have first erased the flash page, so the memory 0x3e100 is all FFF..

3. Shouldn't it be with an 'x' in NRF_LOG_INFO("Writing \"%x\" to flash.", m_data_read); not 's'.

Anyways, you may need to look into how to cast the data to the correct format it was stored in this thread:
https://devzone.nordicsemi.com/f/nordic-q-a/47093/can-i-store-a-struct-in-eeprom-using-nordic-spi-api-and-sent-struct-through-nordic-ble-api 

Best regards,
Kenneth

[melt]

Hi Kenneth

1. I have removed the const still the same

2. I have not erased it, im following the example and they dont mention anything on erasing the flash under the peripheral fstorage  example, also the "Hello world" read and writes works 100% so why would I not be able to read the hex value.

3.correct thanks I have changed it to %x

my problem is   rc = nrf_fstorage_read(&fstorage, 0x3f000, m_data_read, sizeof(m_data_read)); has a 3rd argument. when im reading just a hex byte what do I put as length - 1?

im looking at the below lib explanation of the various functions

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.0.0%2Fgroup__nrf__fstorage.html&anchor=gaebb4176a9aa38b3398e446efa0592939

should I not use a pointer to that hex value in flash and dereference it?

  m_data_pointer = *nrf_fstorage_rmap(&fstorage, 0x3e100);

I dont think im using the right function to read a hex value.

thanks for the help

[Kenneth]

Have you first made sure it's stored as expected by calling: 

nrfjprog  --memrd 0x3E100 --n 100

[melt]

Hi Kenneth

I can confirm it is written correctly. 

.

Segger is showing a warrning as follow on the following read function

rc = nrf_fstorage_read(&fstorage, 0x90000, &m_data_read,sizeof(m_data_read));

warning : argument 3 of 'nrf_fstorage_read' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]

[Kenneth]

'const' typically means the variable is fixed (read-only) and thereby cannot be updated. I suggest to remove the const for any variable you want to be able to update run-time.

https://www.geeksforgeeks.org/how-to-modify-a-const-variable-in-c/

[melt]

thanks but it does do anything

what should I add in the 3rd argument in the function  namely size ? &m_data_read,sizeof(m_data_read));

[Kenneth]

typedef struct
{
    uint32_t data_uint32;                                  
    float  data_float;                              
    char string[12];
} my_data;

my_data m_my_data;
my_data m_my_data_readback;

    memset(&m_my_data, 0, sizeof(m_my_data));
    memset(&m_my_data_readback, 0, sizeof(m_my_data_readback));
    
    m_my_data.data_uint32 = 123;
    m_my_data.data_float = 456.789;    
    memcpy(m_my_data.string, m_hello_world_read, sizeof(m_my_data.string)-1);  
    
    NRF_LOG_INFO("Writing " NRF_LOG_FLOAT_MARKER " to flash.", NRF_LOG_FLOAT(m_my_data.data_float));
    rc = nrf_fstorage_write(&fstorage, 0x3e300, &m_my_data, sizeof(m_my_data), NULL);
    APP_ERROR_CHECK(rc);

    wait_for_flash_ready(&fstorage);
    NRF_LOG_INFO("Done.");

    rc = nrf_fstorage_read(&fstorage, 0x3e300, &m_my_data_readback, sizeof(m_my_data_readback));
    APP_ERROR_CHECK(rc);
    NRF_LOG_INFO("Reading " NRF_LOG_FLOAT_MARKER " from flash.", NRF_LOG_FLOAT(m_my_data_readback.data_float));

    wait_for_flash_ready(&fstorage);
    NRF_LOG_INFO("Done.");

NRF_LOG is not very fond of float values, but the above seems to work. The above example will store both an uint32, float, and a string, but for the purpose of the example only output the float value.

[melt]

Thank you very much