First calling ble_bas_battery_level_update() failed errCode=0x8

[snowuyl]

First calling ble_bas_battery_level_update() failed errCode=0x8. But afterward calling ble_bas_battery_level_update() successfully.

# SEGGER J-Link RTT Viewer V6.32i Terminal Log File
# Compiled: 15:22:50 on Jul 24 2018
# Logging started @ 14 Jul 2022 15:28:04
 0> <info> app: Version 1.0.0
 0>
 0> <info> app: ========| flash info |========
 0> <info> app: erase unit:   4096 bytes
 0> <info> app: program unit: 4 bytes
 0> <info> app: end address: 0x7FFFF
 0> <info> app: ==============================
 0> <info> app_timer: RTC: initialized.
 0> <debug> app: NOR_DATA_PERIOD=819
 0>
 0> <debug> app: NOR_RECORD_PERIOD=8192
 0>
 0> <info> app: bsp_button_longkey_handler 0.
 0> <warning> app: Battery volage 85mV is too low
 0>
 0> <warning> app: Battery volage 17mV is too low
 0>
 0> <info> app: Reg 9 A
 0> <info> app: bsp_button_longkey_handler 1.
 0> <debug> nrf_ble_gatt: Requesting to update ATT MTU to 185 bytes on connection 0x0.
 0> <info> app: Connected.
 0> <debug> app: state=1
 0>
 0> <debug> nrf_ble_gatt: ATT MTU updated to 185 bytes on connection 0x0 (response).
 0> <info> ble_bas: Battery level has been updated: 0%
 0> <debug> ble_bas: Error: 0x00000008 while sending notification with conn_handle: 0x0000
 0> <warning> app: ble_bas_battery_level_update() failed errCode=0x8
 0>
 0> <debug> app: mv=2144, percent=0
 0>
 0> <info> ble_bas: Battery level has been updated: 69%
 0> <info> ble_bas: Battery notification has been sent using conn_handle: 0x0000
 0> <debug> app: mv=3998, percent=69
 0>
 0> <info> ble_bas: Battery level has been updated: 0%
 0> <info> ble_bas: Battery notification has been sent using conn_handle: 0x0000
 0> <debug> app: mv=8, percent=0
 0>
 0> <debug> app: mv=196, percent=0
 0>
 0> <info> ble_bas: Battery level has been updated: 85%
 0> <info> ble_bas: Battery notification has been sent using conn_handle: 0x0000
 0> <debug> app: mv=4101, percent=85
 0>
 0> <info> ble_bas: Battery level has been updated: 0%
 0> <info> ble_bas: Battery notification has been sent using conn_handle: 0x0000
 0> <debug> app: mv=1922, percent=0
 0>

[snowuyl]

Fullscreen battery_ble.c Download

#include "sdk_config.h"
#include "battery_ble.h"
#include "ble_bas.h"
#include "battery_voltage.h"
#include "ble_srv_common.h"
#include "error.h"
#include "nrf_log.h"

#define INVALID_BATTERY_LEVEL 0xFF // Invalid/default battery level.

static bool      _gBleBasInitialized = false;
static ble_bas_t _gBleBas;

/* Event handler, handles events in the Battery Service.
 *
 * details This callback function is often used to enable a service when requested over BLE,
 * and disable when not requested to save power. m_batt_meas runs all the time, so no
 * enabling/disabling is performed.
 */
static void _batteryBleEvtHandler(ble_bas_t * pBas, ble_bas_evt_t * pEvt)
{
    switch (pEvt->evt_type)
    {
        case BLE_BAS_EVT_NOTIFICATION_ENABLED:
            NRF_LOG_DEBUG("BLE_BAS_EVT_NOTIFICATION_ENABLED \n");
            break;

        case BLE_BAS_EVT_NOTIFICATION_DISABLED:
            NRF_LOG_DEBUG("BLE_BAS_EVT_NOTIFICATION_DISABLED \n");
            break;

        default:
            break;
    }
}

int batteryBleInit(void) {
    // Initialize Battery Service.
    ble_bas_init_t basInit;
    memset(&basInit, 0, sizeof(basInit));

    // Security level for the Battery Service
    basInit.bl_rd_sec        = SEC_OPEN;
    basInit.bl_cccd_wr_sec   = SEC_OPEN;
    basInit.bl_report_rd_sec = SEC_OPEN;

    basInit.evt_handler          = _batteryBleEvtHandler;
    basInit.support_notification = true;
    basInit.p_report_ref         = NULL;
    basInit.initial_batt_level   = INVALID_BATTERY_LEVEL;

    const ret_code_t errCode = ble_bas_init(&_gBleBas, &basInit);
    if (errCode != NRF_SUCCESS) {
        NRF_LOG_WARNING("ble_bas_init() failed\n");
        return ERROR_BLE_BAS_INITIALIZE_FAIL;
    }
    
    _gBleBasInitialized = true;

    return 0;
}

int batteryBleUpdate(void) {
    if (!_gBleBasInitialized) {
        return ERROR_BLE_BAS_UNINITIALIZED;
    }

    const int mv          = batteryVoltageGet();
    const uint8_t percent = batteryVoltage2Percent(mv);
    ret_code_t errCode    = ble_bas_battery_level_update(&_gBleBas, percent, BLE_CONN_HANDLE_ALL);
    if (errCode != NRF_SUCCESS) {
        NRF_LOG_WARNING("ble_bas_battery_level_update() failed errCode=0x%x\n", errCode);
        return ERROR_BLE_BAS_UPDATE_FAIL;
    }

    NRF_LOG_DEBUG("mv=%d, percent=%u\n", mv, percent);

    return 0;
}

battery_ble.h

[Simonr]

Hi

Error 8 points to the device being in an invalid state, where the operation ble_bas_battery_level_update() is not allowed. My guess is that the first battery level update is called too early after the MTU update.

Best regards,

Simon

[snowuyl]

Thanks for your reply!