Diff: Eddystone/EddystoneService.cpp

Revision:

0:47dfd44d8b78

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Eddystone/EddystoneService.cpp	Tue Apr 10 12:50:20 2018 +0000
@@ -0,0 +1,570 @@
+/* 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;
+}