The eddystone config service allows you to configure the eddystone frame data over BLE for a set period of time and then starts an eddystone beacon. This example defaults to 30 seconds of config time.

Dependencies:   BLE_API mbed nRF51822 X_NUCLEO_IDB0XA1

Fork of BLE_EddystoneBeaconConfigServiceRelease by Austin Blackstone

This is the eddystone config service. This code starts up and for a user configured time period (default 30 seconds) will advertise the configuration service.

The configuration service allows for modifying various frames of the eddystone specification.

For more details on the Configuration Service please see : https://github.com/google/eddystone/blob/master/eddystone-url/docs/config-service-spec.md

EddystoneService.cpp

Committer:
Vincent Coubard
Date:
2016-09-20
Revision:
8:f53d48e5d64f
Parent:
6:321047f0190a

File content as of revision 8:f53d48e5d64f:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2015 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "EddystoneService.h"

/* Initialise the EddystoneService using parameters from persistent storage */
EddystoneService::EddystoneService(BLE                 &bleIn,
                                   EddystoneParams_t   &paramsIn,
                                   const PowerLevels_t &advPowerLevelsIn,
                                   const PowerLevels_t &radioPowerLevelsIn,
                                   uint32_t            advConfigIntervalIn) :
    ble(bleIn),
    operationMode(EDDYSTONE_MODE_NONE),
    urlFrame(paramsIn.urlData, paramsIn.urlDataLength),
    uidFrame(paramsIn.uidNamespaceID, paramsIn.uidInstanceID),
    tlmFrame(paramsIn.tlmVersion),
    resetFlag(false),
    tlmBatteryVoltageCallback(NULL),
    tlmBeaconTemperatureCallback(NULL)
{
    lockState         = paramsIn.lockState;
    flags             = paramsIn.flags;
    txPowerMode       = paramsIn.txPowerMode;
    beaconPeriod      = correctAdvertisementPeriod(paramsIn.beaconPeriod);

    memcpy(lock,             paramsIn.lock,      sizeof(Lock_t));
    memcpy(unlock,           paramsIn.unlock,    sizeof(Lock_t));

    eddystoneConstructorHelper(advPowerLevelsIn, radioPowerLevelsIn, advConfigIntervalIn);
}

/* When using this constructor we need to call setURLData,
 * setTMLData and setUIDData to initialise values manually
 */
EddystoneService::EddystoneService(BLE                 &bleIn,
                                   const PowerLevels_t &advPowerLevelsIn,
                                   const PowerLevels_t &radioPowerLevelsIn,
                                   uint32_t            advConfigIntervalIn) :
    ble(bleIn),
    operationMode(EDDYSTONE_MODE_NONE),
    urlFrame(),
    uidFrame(),
    tlmFrame(),
    lockState(false),
    resetFlag(false),
    lock(),
    unlock(),
    flags(0),
    txPowerMode(0),
    beaconPeriod(DEFAULT_BEACON_PERIOD_MSEC),
    tlmBatteryVoltageCallback(NULL),
    tlmBeaconTemperatureCallback(NULL)
{
    eddystoneConstructorHelper(advPowerLevelsIn, radioPowerLevelsIn, advConfigIntervalIn);
}

/* Setup callback to update BatteryVoltage in TLM frame */
void EddystoneService::onTLMBatteryVoltageUpdate(TlmUpdateCallback_t tlmBatteryVoltageCallbackIn)
{
    tlmBatteryVoltageCallback = tlmBatteryVoltageCallbackIn;
}

/* Setup callback to update BeaconTemperature in TLM frame */
void EddystoneService::onTLMBeaconTemperatureUpdate(TlmUpdateCallback_t tlmBeaconTemperatureCallbackIn)
{
    tlmBeaconTemperatureCallback = tlmBeaconTemperatureCallbackIn;
}

void EddystoneService::setTLMData(uint8_t tlmVersionIn)
{
   tlmFrame.setTLMData(tlmVersionIn);
}

void EddystoneService::setURLData(const char *urlDataIn)
{
    urlFrame.setURLData(urlDataIn);
}

void EddystoneService::setUIDData(const UIDNamespaceID_t *uidNamespaceIDIn, const UIDInstanceID_t *uidInstanceIDIn)
{
    uidFrame.setUIDData(uidNamespaceIDIn, uidInstanceIDIn);
}

EddystoneService::EddystoneError_t EddystoneService::startConfigService(void)
{
    if (operationMode == EDDYSTONE_MODE_CONFIG) {
        /* Nothing to do, we are already in config mode */
        return EDDYSTONE_ERROR_NONE;
    } else if (advConfigInterval == 0) {
        /* Nothing to do, the advertisement interval is 0 */
        return EDDYSTONE_ERROR_INVALID_ADVERTISING_INTERVAL;
    }

    if (operationMode == EDDYSTONE_MODE_BEACON) {
        ble.shutdown();
        /* Free unused memory */
        freeBeaconFrames();
        operationMode = EDDYSTONE_MODE_CONFIG;
        ble.init(this, &EddystoneService::bleInitComplete);
        return EDDYSTONE_ERROR_NONE;
    }

    operationMode = EDDYSTONE_MODE_CONFIG;
    setupConfigService();
    return EDDYSTONE_ERROR_NONE;
}

EddystoneService::EddystoneError_t EddystoneService::startBeaconService(uint16_t consecUrlFramesIn, uint16_t consecUidFramesIn, uint16_t consecTlmFramesIn)
{
    if (operationMode == EDDYSTONE_MODE_BEACON) {
        /* Nothing to do, we are already in beacon mode */
        return EDDYSTONE_ERROR_NONE;
    } else if (!consecUrlFramesIn && !consecUidFramesIn && !consecTlmFramesIn) {
        /* Nothing to do, the user wants 0 consecutive frames of everything */
        return EDDYSTONE_ERROR_INVALID_CONSEC_FRAMES;
    } else if (!beaconPeriod) {
        /* Nothing to do, the period is 0 for all frames */
        return EDDYSTONE_ERROR_INVALID_BEACON_PERIOD;
    }

    /* Setup tracking of the current advertised frame. Note that this will
     * cause URL or UID frames to be advertised first!
     */
    currentAdvertisedFrame            = EDDYSTONE_FRAME_TLM;
    consecFrames[EDDYSTONE_FRAME_URL] = consecUrlFramesIn;
    consecFrames[EDDYSTONE_FRAME_UID] = consecUidFramesIn;
    consecFrames[EDDYSTONE_FRAME_TLM] = consecTlmFramesIn;

    memset(currentConsecFrames, 0, sizeof(uint16_t) * NUM_EDDYSTONE_FRAMES);

    if (operationMode == EDDYSTONE_MODE_CONFIG) {
        ble.shutdown();
        /* Free unused memory */
        freeConfigCharacteristics();
        operationMode = EDDYSTONE_MODE_BEACON;
        ble.init(this, &EddystoneService::bleInitComplete);
        return EDDYSTONE_ERROR_NONE;
    }

    operationMode = EDDYSTONE_MODE_BEACON;
    setupBeaconService();
    return EDDYSTONE_ERROR_NONE;
}

/* It is not the responsibility of the Eddystone implementation to store
 * the configured parameters in persistent storage since this is
 * platform-specific. So we provide this function that returns the
 * configured values that need to be stored and the main application
 * takes care of storing them.
 */
void EddystoneService::getEddystoneParams(EddystoneParams_t *params)
{
    params->lockState     = lockState;
    params->flags         = flags;
    params->txPowerMode   = txPowerMode;
    params->beaconPeriod  = beaconPeriod;
    params->tlmVersion    = tlmFrame.getTLMVersion();
    params->urlDataLength = urlFrame.getEncodedURLDataLength();

    memcpy(params->advPowerLevels, advPowerLevels,               sizeof(PowerLevels_t));
    memcpy(params->lock,           lock,                         sizeof(Lock_t));
    memcpy(params->unlock,         unlock,                       sizeof(Lock_t));
    memcpy(params->urlData,        urlFrame.getEncodedURLData(), urlFrame.getEncodedURLDataLength());
    memcpy(params->uidNamespaceID, uidFrame.getUIDNamespaceID(), sizeof(UIDNamespaceID_t));
    memcpy(params->uidInstanceID,  uidFrame.getUIDInstanceID(),  sizeof(UIDInstanceID_t));
}

/* Helper function used only once during constructing the object to avoid
 * duplicated code.
 */
void EddystoneService::eddystoneConstructorHelper(const PowerLevels_t &advPowerLevelsIn,
                                                  const PowerLevels_t &radioPowerLevelsIn,
                                                  uint32_t            advConfigIntervalIn)
{
    advConfigInterval = (advConfigIntervalIn > 0) ? correctAdvertisementPeriod(advConfigIntervalIn) : 0;

    memcpy(radioPowerLevels, radioPowerLevelsIn, sizeof(PowerLevels_t));
    memcpy(advPowerLevels,   advPowerLevelsIn,   sizeof(PowerLevels_t));

    /* TODO: Note that this timer is started from the time EddystoneService
     * is initialised and NOT from when the device is booted. So app needs
     * to take care that EddystoneService is one of the first things to be
     * started!
     */
    timeSinceBootTimer.start();
}

/* When changing modes, we shutdown and init the BLE instance, so
 * this is needed to complete the initialisation task.
 */
void EddystoneService::bleInitComplete(BLE::InitializationCompleteCallbackContext* initContext)
{
    if (initContext->error != BLE_ERROR_NONE) {
        /* Initialisation failed */
        return;
    }

    switch (operationMode) {
    case EDDYSTONE_MODE_CONFIG:
        setupConfigService();
        break;
    case EDDYSTONE_MODE_BEACON:
        setupBeaconService();
        break;
    default:
        /* Some error occurred */
        break;
    }
}

void EddystoneService::swapAdvertisedFrame(void)
{
    /* This essentially works out which is the next frame to be swapped in
     * and updated the advertised packets. It will eventually terminate
     * and in the worst case the frame swapped in is the current advertised
     * frame.
     */
    while (true) {
        currentAdvertisedFrame = (currentAdvertisedFrame + 1) % NUM_EDDYSTONE_FRAMES;

        if (currentAdvertisedFrame == EDDYSTONE_FRAME_URL && consecFrames[EDDYSTONE_FRAME_URL] > 0) {
            updateAdvertisementPacket(rawUrlFrame, urlFrame.getRawFrameSize());
            return;
        } else if (currentAdvertisedFrame == EDDYSTONE_FRAME_UID && consecFrames[EDDYSTONE_FRAME_UID] > 0) {
            updateAdvertisementPacket(rawUidFrame, uidFrame.getRawFrameSize());
            return;
        } else if (currentAdvertisedFrame == EDDYSTONE_FRAME_TLM && consecFrames[EDDYSTONE_FRAME_UID] > 0) {
            updateRawTLMFrame();
            updateAdvertisementPacket(rawTlmFrame, tlmFrame.getRawFrameSize());
            return;
        }
    }
}

/* Helper function that calls user-defined functions to update Battery Voltage and Temperature (if available),
 * then updates the raw frame data and finally updates the actual advertised packet. This operation must be
 * done fairly often because the TLM frame TimeSinceBoot must have a 0.1 secs resolution according to the
 * Eddystone specification.
 */
void EddystoneService::updateRawTLMFrame(void)
{
    if (tlmBeaconTemperatureCallback != NULL) {
        tlmFrame.updateBeaconTemperature((*tlmBeaconTemperatureCallback)(tlmFrame.getBeaconTemperature()));
    }
    if (tlmBatteryVoltageCallback != NULL) {
        tlmFrame.updateBatteryVoltage((*tlmBatteryVoltageCallback)(tlmFrame.getBatteryVoltage()));
    }
    tlmFrame.updateTimeSinceBoot(timeSinceBootTimer.read_ms());
    tlmFrame.constructTLMFrame(rawTlmFrame);
}

void EddystoneService::updateAdvertisementPacket(const uint8_t* rawFrame, size_t rawFrameLength)
{
    ble.gap().clearAdvertisingPayload();
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, EDDYSTONE_UUID, sizeof(EDDYSTONE_UUID));
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, rawFrame, rawFrameLength);
}

void EddystoneService::setupBeaconService(void)
{
    /* Initialise arrays to hold constructed raw frames */
    if (consecFrames[EDDYSTONE_FRAME_URL] > 0) {
        rawUrlFrame = new uint8_t[urlFrame.getRawFrameSize()];
        urlFrame.constructURLFrame(rawUrlFrame, advPowerLevels[txPowerMode]);
    }

    if (consecFrames[EDDYSTONE_FRAME_UID] > 0) {
        rawUidFrame = new uint8_t[uidFrame.getRawFrameSize()];
        uidFrame.constructUIDFrame(rawUidFrame, advPowerLevels[txPowerMode]);
    }

    if (consecFrames[EDDYSTONE_FRAME_TLM] > 0) {
        rawTlmFrame = new uint8_t[tlmFrame.getRawFrameSize()];
        /* Do not initialise because we have to reconstruct every 0.1 secs */
    }

    /* Configure advertisements */
    ble.gap().setTxPower(radioPowerLevels[txPowerMode]);
    ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_NON_CONNECTABLE_UNDIRECTED);
    ble.gap().setAdvertisingInterval(beaconPeriod);
    ble.gap().onRadioNotification(this, &EddystoneService::radioNotificationCallback);
    ble.gap().initRadioNotification();

    /* Set advertisement packet payload */
    swapAdvertisedFrame();

    /* Start advertising */
    ble.gap().startAdvertising();
}

void EddystoneService::setupConfigService(void)
{
    lockStateChar      = new ReadOnlyGattCharacteristic<bool>(UUID_LOCK_STATE_CHAR, &lockState);
    lockChar           = new WriteOnlyArrayGattCharacteristic<uint8_t, sizeof(Lock_t)>(UUID_LOCK_CHAR, lock);
    unlockChar         = new WriteOnlyArrayGattCharacteristic<uint8_t, sizeof(Lock_t)>(UUID_UNLOCK_CHAR, unlock);
    urlDataChar        = new GattCharacteristic(UUID_URL_DATA_CHAR, urlFrame.getEncodedURLData(), 0, URL_DATA_MAX, GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE);
    flagsChar          = new ReadWriteGattCharacteristic<uint8_t>(UUID_FLAGS_CHAR, &flags);
    advPowerLevelsChar = new ReadWriteArrayGattCharacteristic<int8_t, sizeof(PowerLevels_t)>(UUID_ADV_POWER_LEVELS_CHAR, advPowerLevels);
    txPowerModeChar    = new ReadWriteGattCharacteristic<uint8_t>(UUID_TX_POWER_MODE_CHAR, &txPowerMode);
    beaconPeriodChar   = new ReadWriteGattCharacteristic<uint16_t>(UUID_BEACON_PERIOD_CHAR, &beaconPeriod);
    resetChar          = new WriteOnlyGattCharacteristic<bool>(UUID_RESET_CHAR, &resetFlag);

    lockChar->setWriteAuthorizationCallback(this, &EddystoneService::lockAuthorizationCallback);
    unlockChar->setWriteAuthorizationCallback(this, &EddystoneService::unlockAuthorizationCallback);
    urlDataChar->setWriteAuthorizationCallback(this, &EddystoneService::urlDataWriteAuthorizationCallback);
    flagsChar->setWriteAuthorizationCallback(this, &EddystoneService::basicAuthorizationCallback<uint8_t>);
    advPowerLevelsChar->setWriteAuthorizationCallback(this, &EddystoneService::basicAuthorizationCallback<PowerLevels_t>);
    txPowerModeChar->setWriteAuthorizationCallback(this, &EddystoneService::powerModeAuthorizationCallback);
    beaconPeriodChar->setWriteAuthorizationCallback(this, &EddystoneService::basicAuthorizationCallback<uint16_t>);
    resetChar->setWriteAuthorizationCallback(this, &EddystoneService::basicAuthorizationCallback<bool>);

    charTable[0] = lockStateChar;
    charTable[1] = lockChar;
    charTable[2] = unlockChar;
    charTable[3] = urlDataChar;
    charTable[4] = flagsChar;
    charTable[5] = advPowerLevelsChar;
    charTable[6] = txPowerModeChar;
    charTable[7] = beaconPeriodChar;
    charTable[8] = resetChar;

    GattService configService(UUID_URL_BEACON_SERVICE, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));

    ble.gattServer().addService(configService);
    ble.gattServer().onDataWritten(this, &EddystoneService::onDataWrittenCallback);
    updateCharacteristicValues();
    setupEddystoneConfigAdvertisements();
}

void EddystoneService::freeConfigCharacteristics(void)
{
    delete lockStateChar;
    delete lockChar;
    delete unlockChar;
    delete urlDataChar;
    delete flagsChar;
    delete advPowerLevelsChar;
    delete txPowerModeChar;
    delete beaconPeriodChar;
    delete resetChar;
}

void EddystoneService::freeBeaconFrames(void)
{
    delete[] rawUrlFrame;
    delete[] rawUidFrame;
    delete[] rawTlmFrame;
}

void EddystoneService::radioNotificationCallback(bool radioActive)
{
    if (radioActive) {
        /* Do nothing */
        return;
    }

    tlmFrame.updatePduCount();
    currentConsecFrames[currentAdvertisedFrame]++;

    if (consecFrames[currentAdvertisedFrame] > currentConsecFrames[currentAdvertisedFrame]) {
        if (currentAdvertisedFrame == EDDYSTONE_FRAME_TLM) {
            /* Update the TLM frame otherwise we will not meet the 0.1 secs resolution of
             * the Eddystone specification.
             */
            updateRawTLMFrame();
            updateAdvertisementPacket(rawTlmFrame, tlmFrame.getRawFrameSize());
        }
        /* Keep advertising the same frame */
        return;
    }

    currentConsecFrames[currentAdvertisedFrame] = 0;

#ifdef YOTTA_CFG_MBED_OS
    minar::Scheduler::postCallback(this, &EddystoneService::swapAdvertisedFrame);
#else
    swapAdvertisedFrameTimeout.attach_us(this, &EddystoneService::swapAdvertisedFrame, 1);
#endif
}

/*
 * Internal helper function used to update the GATT database following any
 * change to the internal state of the service object.
 */
void EddystoneService::updateCharacteristicValues(void)
{
    ble.gattServer().write(lockStateChar->getValueHandle(), reinterpret_cast<uint8_t *>(&lockState), sizeof(bool));
    ble.gattServer().write(urlDataChar->getValueHandle(), urlFrame.getEncodedURLData(), urlFrame.getEncodedURLDataLength());
    ble.gattServer().write(flagsChar->getValueHandle(), &flags, sizeof(uint8_t));
    ble.gattServer().write(beaconPeriodChar->getValueHandle(), reinterpret_cast<uint8_t *>(&beaconPeriod), sizeof(uint16_t));
    ble.gattServer().write(txPowerModeChar->getValueHandle(), &txPowerMode, sizeof(uint8_t));
    ble.gattServer().write(advPowerLevelsChar->getValueHandle(), reinterpret_cast<uint8_t *>(advPowerLevels), sizeof(PowerLevels_t));
    ble.gattServer().write(lockChar->getValueHandle(), lock, sizeof(PowerLevels_t));
    ble.gattServer().write(unlockChar->getValueHandle(), unlock, sizeof(PowerLevels_t));
}

void EddystoneService::setupEddystoneConfigAdvertisements(void)
{
    ble.gap().clearAdvertisingPayload();
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);

    /* UUID is in different order in the ADV frame (!) */
    uint8_t reversedServiceUUID[sizeof(UUID_URL_BEACON_SERVICE)];
    for (size_t i = 0; i < sizeof(UUID_URL_BEACON_SERVICE); i++) {
        reversedServiceUUID[i] = UUID_URL_BEACON_SERVICE[sizeof(UUID_URL_BEACON_SERVICE) - i - 1];
    }
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_128BIT_SERVICE_IDS, reversedServiceUUID, sizeof(reversedServiceUUID));
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::GENERIC_TAG);
    ble.gap().accumulateScanResponse(GapAdvertisingData::COMPLETE_LOCAL_NAME, reinterpret_cast<const uint8_t *>(&DEVICE_NAME), sizeof(DEVICE_NAME));
    ble.gap().accumulateScanResponse(
        GapAdvertisingData::TX_POWER_LEVEL,
        reinterpret_cast<uint8_t *>(&advPowerLevels[TX_POWER_MODE_LOW]),
        sizeof(uint8_t));

    ble.gap().setTxPower(radioPowerLevels[txPowerMode]);
    ble.gap().setDeviceName(reinterpret_cast<const uint8_t *>(&DEVICE_NAME));
    ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
    ble.gap().setAdvertisingInterval(advConfigInterval);
    ble.gap().startAdvertising();
}

void EddystoneService::lockAuthorizationCallback(GattWriteAuthCallbackParams *authParams)
{
    if (lockState) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INSUF_AUTHORIZATION;
    } else if (authParams->len != sizeof(Lock_t)) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INVALID_ATT_VAL_LENGTH;
    } else if (authParams->offset != 0) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INVALID_OFFSET;
    } else {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_SUCCESS;
    }
}

void EddystoneService::unlockAuthorizationCallback(GattWriteAuthCallbackParams *authParams)
{
    if (!lockState && (authParams->len == sizeof(Lock_t))) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_SUCCESS;
    } else if (authParams->len != sizeof(Lock_t)) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INVALID_ATT_VAL_LENGTH;
    } else if (authParams->offset != 0) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INVALID_OFFSET;
    } else if (memcmp(authParams->data, lock, sizeof(Lock_t)) != 0) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INSUF_AUTHORIZATION;
    } else {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_SUCCESS;
    }
}

void EddystoneService::urlDataWriteAuthorizationCallback(GattWriteAuthCallbackParams *authParams)
{
    if (lockState) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INSUF_AUTHORIZATION;
    } else if (authParams->offset != 0) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INVALID_OFFSET;
    } else {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_SUCCESS;
    }
}

void EddystoneService::powerModeAuthorizationCallback(GattWriteAuthCallbackParams *authParams)
{
    if (lockState) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INSUF_AUTHORIZATION;
    } else if (authParams->len != sizeof(uint8_t)) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INVALID_ATT_VAL_LENGTH;
    } else if (authParams->offset != 0) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INVALID_OFFSET;
    } else if (*((uint8_t *)authParams->data) >= NUM_POWER_MODES) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_WRITE_NOT_PERMITTED;
    } else {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_SUCCESS;
    }
}

template <typename T>
void EddystoneService::basicAuthorizationCallback(GattWriteAuthCallbackParams *authParams)
{
    if (lockState) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INSUF_AUTHORIZATION;
    } else if (authParams->len != sizeof(T)) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INVALID_ATT_VAL_LENGTH;
    } else if (authParams->offset != 0) {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INVALID_OFFSET;
    } else {
        authParams->authorizationReply = AUTH_CALLBACK_REPLY_SUCCESS;
    }
}

/*
 * This callback is invoked when a GATT client attempts to modify any of the
 * characteristics of this service. Attempts to do so are also applied to
 * the internal state of this service object.
 */
void EddystoneService::onDataWrittenCallback(const GattWriteCallbackParams *writeParams)
{
    uint16_t handle = writeParams->handle;

    if (handle == lockChar->getValueHandle()) {
        memcpy(lock, writeParams->data, sizeof(Lock_t));
        /* Set the state to be locked by the lock code (note: zeros are a valid lock) */
        lockState = true;
        ble.gattServer().write(lockChar->getValueHandle(), lock, sizeof(PowerLevels_t));
        ble.gattServer().write(lockStateChar->getValueHandle(), reinterpret_cast<uint8_t *>(&lockState), sizeof(bool));
    } else if (handle == unlockChar->getValueHandle()) {
        /* Validated earlier */
        lockState = false;
        ble.gattServer().write(unlockChar->getValueHandle(), unlock, sizeof(PowerLevels_t));
        ble.gattServer().write(lockStateChar->getValueHandle(), reinterpret_cast<uint8_t *>(&lockState), sizeof(bool));
    } else if (handle == urlDataChar->getValueHandle()) {
        urlFrame.setEncodedURLData(writeParams->data, writeParams->len);
        ble.gattServer().write(urlDataChar->getValueHandle(), urlFrame.getEncodedURLData(), urlFrame.getEncodedURLDataLength());
    } else if (handle == flagsChar->getValueHandle()) {
        flags = *(writeParams->data);
        ble.gattServer().write(flagsChar->getValueHandle(), &flags, sizeof(uint8_t));
    } else if (handle == advPowerLevelsChar->getValueHandle()) {
        memcpy(advPowerLevels, writeParams->data, sizeof(PowerLevels_t));
        ble.gattServer().write(advPowerLevelsChar->getValueHandle(), reinterpret_cast<uint8_t *>(advPowerLevels), sizeof(PowerLevels_t));
    } else if (handle == txPowerModeChar->getValueHandle()) {
        txPowerMode = *(writeParams->data);
        ble.gattServer().write(txPowerModeChar->getValueHandle(), &txPowerMode, sizeof(uint8_t));
    } else if (handle == beaconPeriodChar->getValueHandle()) {
        uint16_t tmpBeaconPeriod = correctAdvertisementPeriod(*((uint16_t *)(writeParams->data)));
        if (tmpBeaconPeriod != beaconPeriod) {
            beaconPeriod = tmpBeaconPeriod;
            ble.gattServer().write(beaconPeriodChar->getValueHandle(), reinterpret_cast<uint8_t *>(&beaconPeriod), sizeof(uint16_t));
        }
    } else if (handle == resetChar->getValueHandle() && (*((uint8_t *)writeParams->data) != 0)) {
        /* Reset characteristics to default values */
        flags        = 0;
        txPowerMode  = TX_POWER_MODE_LOW;
        beaconPeriod = DEFAULT_BEACON_PERIOD_MSEC;

        urlFrame.setURLData(DEFAULT_URL);
        memset(lock, 0, sizeof(Lock_t));

        ble.gattServer().write(urlDataChar->getValueHandle(), urlFrame.getEncodedURLData(), urlFrame.getEncodedURLDataLength());
        ble.gattServer().write(flagsChar->getValueHandle(), &flags, sizeof(uint8_t));
        ble.gattServer().write(txPowerModeChar->getValueHandle(), &txPowerMode, sizeof(uint8_t));
        ble.gattServer().write(beaconPeriodChar->getValueHandle(), reinterpret_cast<uint8_t *>(&beaconPeriod), sizeof(uint16_t));
        ble.gattServer().write(lockChar->getValueHandle(), lock, sizeof(PowerLevels_t));
    }
}

uint16_t EddystoneService::correctAdvertisementPeriod(uint16_t beaconPeriodIn) const
{
    /* Re-map beaconPeriod to within permissible bounds if necessary. */
    if (beaconPeriodIn != 0) {
        if (beaconPeriodIn < ble.gap().getMinAdvertisingInterval()) {
            return ble.gap().getMinAdvertisingInterval();
        } else if (beaconPeriodIn > ble.gap().getMaxAdvertisingInterval()) {
            return ble.gap().getMaxAdvertisingInterval();
        }
    }
    return beaconPeriodIn;
}