diff --git a/ble/BLE.h b/ble/BLE.h
index 5484c40..d95471c 100644
--- a/ble/BLE.h
+++ b/ble/BLE.h
@@ -23,6 +23,8 @@
 #include "GattClient.h"
 #include "BLEInstanceBase.h"
 
+#include "mbed_error.h"
+
 /**
  * The base class used to abstract away BLE capable radio transceivers or SOCs,
  * to enable this BLE API to work with any radio transparently.
@@ -50,6 +52,9 @@ public:
      */
     ble_error_t shutdown(void) {
         clearAdvertisingPayload();
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->shutdown();
     }
 
@@ -60,6 +65,9 @@ public:
      *          Note: The string is owned by the BLE_API.
      */
     const char *getVersion(void) {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->getVersion();
     }
 
@@ -68,9 +76,15 @@ public:
      * going through this accessor.
      */
     const Gap &gap() const {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->getGap();
     }
     Gap &gap() {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->getGap();
     }
 
@@ -79,9 +93,15 @@ public:
      * functionality requires going through this accessor.
      */
     const GattServer& gattServer() const {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->getGattServer();
     }
     GattServer& gattServer() {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->getGattServer();
     }
 
@@ -90,9 +110,15 @@ public:
      * functionality requires going through this accessor.
      */
     const GattClient& gattClient() const {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->getGattClient();
     }
     GattClient& gattClient() {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->getGattClient();
     }
 
@@ -102,9 +128,15 @@ public:
      * accessor.
      */
     const SecurityManager& securityManager() const {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->getSecurityManager();
     }
     SecurityManager& securityManager() {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         return transport->getSecurityManager();
     }
 
@@ -116,9 +148,49 @@ public:
      * WFE().
      */
     void waitForEvent(void) {
+        if (!transport) {
+            error("bad handle to underlying transport");
+        }
         transport->waitForEvent();
     }
 
+public:
+    typedef unsigned InstanceID_t;
+    static const InstanceID_t DEFAULT_INSTANCE = 0;
+#ifndef YOTTA_CFG_BLE_INSTANCES_COUNT
+    static const InstanceID_t NUM_INSTANCES = 1;
+#else
+    static const InstanceID_t NUM_INSTANCES = YOTTA_CFG_BLE_INSTANCES_COUNT;
+#endif
+
+    /**
+     * Get a reference to the BLE singleton corresponding to a given interface.
+     * There is a static array of BLE singletons.
+     *
+     * @Note: Calling Instance() is preferred over constructing a BLE object
+     * directly, as it returns references to singletons.
+     *
+     * @param[in] id
+     *              Instance-ID. This should be less than NUM_INSTANCES in order
+     *              for the returned BLE singleton to be useful.
+     *
+     * @return a reference to a single object
+     */
+    static BLE &Instance(InstanceID_t id = DEFAULT_INSTANCE);
+
+    /**
+     * Constructor for a handle to a BLE instance (i.e. BLE stack). BLE handles
+     * are thin wrappers around a transport object (i.e. ptr. to
+     * BLEInstanceBase).
+     *
+     * BLE objects are are better created as singletons accessed through the
+     * Instance() method. If multiple BLE handles are constructed for the same
+     * interface (using this constructor), they will share the same underlying
+     * transport object.
+     */
+    BLE(InstanceID_t instanceID = DEFAULT_INSTANCE);
+
+
     /*
      * Deprecation alert!
      * All of the following are deprecated and may be dropped in a future
@@ -1079,7 +1151,7 @@ public:
     }
 
     /**
-     * Used to setup a callback for GAP disconnection.
+     * Append to a chain of callbacks to be invoked upon GAP disconnection.
      *
      * @note: This API is now *deprecated* and will be dropped in the future.
      * You should use the parallel API from Gap directly. A former call
@@ -1090,19 +1162,9 @@ public:
         gap().onDisconnection(disconnectionCallback);
     }
 
-    /**
-     * Append to a chain of callbacks to be invoked upon disconnection; these
-     * callbacks receive no context and are therefore different from the
-     * onDisconnection callback.
-     *
-     * @note: This API is now *deprecated* and will be dropped in the future.
-     * You should use the parallel API from Gap directly. A former call
-     * to ble.addToDisconnectionCallchain(...) should be replaced with
-     * ble.gap().addToDisconnectionCallchain(...).
-     */
     template<typename T>
-    void addToDisconnectionCallChain(T *tptr, void (T::*mptr)(void)) {
-        gap().addToDisconnectionCallChain(tptr, mptr);
+    void onDisconnection(T *tptr, void (T::*mptr)(const Gap::DisconnectionCallbackParams_t*)) {
+        gap().onDisconnection(tptr, mptr);
     }
 
     /**
@@ -1327,13 +1389,12 @@ public:
         return securityManager().onPasskeyDisplay(callback);
     }
 
-public:
-    BLE() : transport(createBLEInstance()) {
-        /* empty */
-    }
+private:
+    BLE(const BLE&);
+    BLE &operator=(const BLE &);
 
 private:
-    BLEInstanceBase *const transport; /* the device specific backend */
+    BLEInstanceBase *transport; /* the device specific backend */
 };
 
 typedef BLE BLEDevice; /* DEPRECATED. This type alias is retained for the sake of compatibility with older
diff --git a/ble/Gap.h b/ble/Gap.h
index 9540680..06793e9 100644
--- a/ble/Gap.h
+++ b/ble/Gap.h
@@ -21,11 +21,9 @@
 #include "GapAdvertisingParams.h"
 #include "GapScanningParams.h"
 #include "GapEvents.h"
-#include "CallChain.h"
+#include "CallChainOfFunctionPointersWithContext.h"
 #include "FunctionPointerWithContext.h"
 
-using namespace mbed;
-
 /* Forward declarations for classes which will only be used for pointers or references in the following. */
 class GapAdvertisingParams;
 class GapScanningParams;
@@ -126,6 +124,17 @@ public:
         }
     };
 
+    struct DisconnectionCallbackParams_t {
+        Handle_t              handle;
+        DisconnectionReason_t reason;
+
+        DisconnectionCallbackParams_t(Handle_t              handleIn,
+                                      DisconnectionReason_t reasonIn) :
+            handle(handleIn),
+            reason(reasonIn)
+        {}
+    };
+
     static const uint16_t UNIT_1_25_MS  = 1250; /**< Number of microseconds in 1.25 milliseconds. */
     static uint16_t MSEC_TO_GAP_DURATION_UNITS(uint32_t durationInMillis) {
         return (durationInMillis * 1000) / UNIT_1_25_MS;
@@ -134,7 +143,7 @@ public:
 
     typedef void (*TimeoutEventCallback_t)(TimeoutSource_t source);
     typedef void (*ConnectionEventCallback_t)(const ConnectionCallbackParams_t *params);
-    typedef void (*DisconnectionEventCallback_t)(Handle_t, DisconnectionReason_t);
+    typedef void (*DisconnectionEventCallback_t)(const DisconnectionCallbackParams_t *params);
     typedef FunctionPointerWithContext<bool> RadioNotificationEventCallback_t;
 
     /*
@@ -214,7 +223,7 @@ public:
      * @param scanParams
      *          Paramters to be used while scanning for the peer.
      * @return  BLE_ERROR_NONE if connection establishment procedure is started
-     *     successfully. The connectionCallback (if set) will be invoked upon
+     *     successfully. The connectionCallChain (if set) will be invoked upon
      *     a connection event.
      */
     virtual ble_error_t connect(const Address_t           peerAddr,
@@ -301,9 +310,11 @@ public:
     }
 
     /**
-     * Update connection parameters while in the peripheral role.
-     * @details In the peripheral role, this will send the corresponding L2CAP request to the connected peer and wait for
-     *          the central to perform the procedure.
+     * Update connection parameters.
+     * In the central role this will initiate a Link Layer connection parameter update procedure,
+     * otherwise in the peripheral role, this will send the corresponding L2CAP request and wait for
+     * the central to perform the procedure.
+     *
      * @param[in] handle
      *              Connection Handle
      * @param[in] params
@@ -889,26 +900,20 @@ public:
     void onTimeout(TimeoutEventCallback_t callback) {timeoutCallback = callback;}
 
     /**
-     * Setup a callback for connection events. Refer to ConnectionEventCallback_t.
+     * Append to a chain of callbacks to be invoked upon GAP connection.
      */
-    void onConnection(ConnectionEventCallback_t callback) {connectionCallback = callback;}
+    void onConnection(ConnectionEventCallback_t callback) {connectionCallChain.add(callback);}
 
-    /**
-     * Set the application callback for disconnection events.
-     * @param callback
-     *        Pointer to the unique callback.
-     */
-    void onDisconnection(DisconnectionEventCallback_t callback) {disconnectionCallback = callback;}
-
-    /**
-     * Append to a chain of callbacks to be invoked upon disconnection; these
-     * callbacks receive no context and are therefore different from the
-     * disconnectionCallback callback.
-     * @param callback
-     *        function pointer to be invoked upon disconnection; receives no context.
-     */
     template<typename T>
-    void addToDisconnectionCallChain(T *tptr, void (T::*mptr)(void)) {disconnectionCallChain.add(tptr, mptr);}
+    void onConnection(T *tptr, void (T::*mptr)(const ConnectionCallbackParams_t*)) {connectionCallChain.add(tptr, mptr);}
+
+    /**
+     * Append to a chain of callbacks to be invoked upon GAP disconnection.
+     */
+    void onDisconnection(DisconnectionEventCallback_t callback) {disconnectionCallChain.add(callback);}
+
+    template<typename T>
+    void onDisconnection(T *tptr, void (T::*mptr)(const DisconnectionCallbackParams_t*)) {disconnectionCallChain.add(tptr, mptr);}
 
     /**
      * Set the application callback for radio-notification events.
@@ -956,10 +961,9 @@ protected:
         state(),
         scanningActive(false),
         timeoutCallback(NULL),
-        connectionCallback(NULL),
-        disconnectionCallback(NULL),
         radioNotificationCallback(),
         onAdvertisementReport(),
+        connectionCallChain(),
         disconnectionCallChain() {
         _advPayload.clear();
         _scanResponse.clear();
@@ -975,18 +979,14 @@ public:
                                 const Address_t           ownAddr,
                                 const ConnectionParams_t *connectionParams) {
         state.connected = 1;
-        if (connectionCallback) {
-            ConnectionCallbackParams_t callbackParams(handle, role, peerAddrType, peerAddr, ownAddrType, ownAddr, connectionParams);
-            connectionCallback(&callbackParams);
-        }
+        ConnectionCallbackParams_t callbackParams(handle, role, peerAddrType, peerAddr, ownAddrType, ownAddr, connectionParams);
+        connectionCallChain.call(&callbackParams);
     }
 
     void processDisconnectionEvent(Handle_t handle, DisconnectionReason_t reason) {
         state.connected = 0;
-        if (disconnectionCallback) {
-            disconnectionCallback(handle, reason);
-        }
-        disconnectionCallChain.call();
+        DisconnectionCallbackParams_t callbackParams(handle, reason);
+        disconnectionCallChain.call(&callbackParams);
     }
 
     void processAdvertisementReport(const Address_t    peerAddr,
@@ -1022,11 +1022,10 @@ protected:
 
 protected:
     TimeoutEventCallback_t           timeoutCallback;
-    ConnectionEventCallback_t        connectionCallback;
-    DisconnectionEventCallback_t     disconnectionCallback;
     RadioNotificationEventCallback_t radioNotificationCallback;
     AdvertisementReportCallback_t    onAdvertisementReport;
-    CallChain                        disconnectionCallChain;
+    CallChainOfFunctionPointersWithContext<const ConnectionCallbackParams_t*>    connectionCallChain;
+    CallChainOfFunctionPointersWithContext<const DisconnectionCallbackParams_t*> disconnectionCallChain;
 
 private:
     /* disallow copy and assignment */
diff --git a/ble/GattCallbackParamTypes.h b/ble/GattCallbackParamTypes.h
index 18784c8..50a1788 100644
--- a/ble/GattCallbackParamTypes.h
+++ b/ble/GattCallbackParamTypes.h
@@ -65,8 +65,9 @@ struct GattWriteAuthCallbackParams {
     uint16_t                 offset; /**< Offset for the write operation. */
     uint16_t                 len;    /**< Length of the incoming data. */
     const uint8_t           *data;   /**< Incoming data, variable length. */
-    GattAuthCallbackReply_t  authorizationReply; /* This is the out parameter which needs to be set to true by the callback if the
-                                                  * request is to proceed; false otherwise. */
+    GattAuthCallbackReply_t  authorizationReply; /* This is the out parameter which needs to be set to
+                                                  * AUTH_CALLBACK_REPLY_SUCCESS by the callback if the
+                                                  * request is to proceed. */
 };
 
 struct GattReadAuthCallbackParams {
@@ -75,8 +76,9 @@ struct GattReadAuthCallbackParams {
     uint16_t                 offset; /**< Offset for the read operation. */
     uint16_t                 len;    /**< Optional: new length of the outgoing data. */
     uint8_t                 *data;   /**< Optional: new outgoing data. Leave at NULL if data is unchanged. */
-    GattAuthCallbackReply_t  authorizationReply; /* This is the out parameter which needs to be set to true by the callback if the
-                                                  * request is to proceed; false otherwise. */
+    GattAuthCallbackReply_t  authorizationReply; /* This is the out parameter which needs to be set to
+                                                  * AUTH_CALLBACK_REPLY_SUCCESS by the callback if the
+                                                  * request is to proceed. */
 };
 
 /* For encapsulating handle-value update events (notifications or indications) generated at the remote server. */
diff --git a/ble/GattServer.h b/ble/GattServer.h
index 0f36718..7821798 100644
--- a/ble/GattServer.h
+++ b/ble/GattServer.h
@@ -271,7 +271,7 @@ public:
      *
      * @Note: this functionality may not be available on all underlying stacks.
      * You could use GattCharacteristic::setReadAuthorizationCallback() as an
-     * alternative.
+     * alternative. Refer to isOnDataReadAvailable().
      *
      * @Note: it is possible to chain together multiple onDataRead callbacks
      * (potentially from different modules of an application) to receive updates
diff --git a/ble/services/EddystoneConfigService.h b/ble/services/EddystoneConfigService.h
new file mode 100644
index 0000000..5a06b8b
--- /dev/null
+++ b/ble/services/EddystoneConfigService.h
@@ -0,0 +1,540 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 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.
+ */
+
+#ifndef SERVICES_EDDYSTONE_BEACON_CONFIG_SERVICE_H_
+#define SERVICES_EDDYSTONE_BEACON_CONFIG_SERVICE_H_
+
+#include "mbed.h"
+#include "ble/BLE.h"
+#include "ble/services/EddystoneService.h"
+
+#define UUID_URI_BEACON(FIRST, SECOND) {                         \
+        0xee, 0x0c, FIRST, SECOND, 0x87, 0x86, 0x40, 0xba,       \
+        0xab, 0x96, 0x99, 0xb9, 0x1a, 0xc9, 0x81, 0xd8,          \
+}
+
+static const uint8_t UUID_URI_BEACON_SERVICE[]    = UUID_URI_BEACON(0x20, 0x80);
+static const uint8_t UUID_LOCK_STATE_CHAR[]       = UUID_URI_BEACON(0x20, 0x81);
+static const uint8_t UUID_LOCK_CHAR[]             = UUID_URI_BEACON(0x20, 0x82);
+static const uint8_t UUID_UNLOCK_CHAR[]           = UUID_URI_BEACON(0x20, 0x83);
+static const uint8_t UUID_URI_DATA_CHAR[]         = UUID_URI_BEACON(0x20, 0x84);
+static const uint8_t UUID_FLAGS_CHAR[]            = UUID_URI_BEACON(0x20, 0x85);
+static const uint8_t UUID_ADV_POWER_LEVELS_CHAR[] = UUID_URI_BEACON(0x20, 0x86);
+static const uint8_t UUID_TX_POWER_MODE_CHAR[]    = UUID_URI_BEACON(0x20, 0x87);
+static const uint8_t UUID_BEACON_PERIOD_CHAR[]    = UUID_URI_BEACON(0x20, 0x88);
+static const uint8_t UUID_RESET_CHAR[]            = UUID_URI_BEACON(0x20, 0x89);
+extern const uint8_t BEACON_EDDYSTONE[2];
+
+/**
+* @class EddystoneConfigService
+* @brief Eddystone Configuration Service. Can be used to set URL, adjust power levels, and set flags.
+* See https://github.com/google/eddystone
+*
+*/
+class EddystoneConfigService
+{
+public:
+    /**
+     * @brief Transmission Power Modes for UriBeacon
+     */
+    enum {
+        TX_POWER_MODE_LOWEST,
+        TX_POWER_MODE_LOW,
+        TX_POWER_MODE_MEDIUM,
+        TX_POWER_MODE_HIGH,
+        NUM_POWER_MODES
+    };
+
+    static const unsigned ADVERTISING_INTERVAL_MSEC = 1000; // Advertising interval for config service.
+    static const unsigned SERVICE_DATA_MAX          = 31;   // Maximum size of service data in ADV packets
+
+    typedef uint8_t Lock_t[16];                             /* 128 bits */
+    typedef int8_t PowerLevels_t[NUM_POWER_MODES];
+
+    // There are currently 3 subframes defined, URI, UID, and TLM
+#define EDDYSTONE_MAX_FRAMETYPE 3
+    static const unsigned URI_DATA_MAX = 18;
+    typedef uint8_t UriData_t[URI_DATA_MAX];
+
+    // UID Frame Type subfields
+    static const size_t UID_NAMESPACEID_SIZE = 10;
+    typedef uint8_t UIDNamespaceID_t[UID_NAMESPACEID_SIZE];
+    static const size_t UID_INSTANCEID_SIZE = 6;
+    typedef uint8_t UIDInstanceID_t[UID_INSTANCEID_SIZE];
+
+    // Eddystone Frame Type ID
+    static const uint8_t FRAME_TYPE_UID = 0x00;
+    static const uint8_t FRAME_TYPE_URL = 0x10;
+    static const uint8_t FRAME_TYPE_TLM = 0x20;
+
+    static const uint8_t FRAME_SIZE_TLM = 14; // TLM frame is a constant 14Bytes
+    static const uint8_t FRAME_SIZE_UID = 20; // includes RFU bytes
+
+    struct Params_t {
+        // Config Data
+        bool             isConfigured; // Flag for configuration being complete,
+                                       //   True = configured, false = not configured. Reset at instantiation, used for external callbacks.
+        uint8_t          lockedState;
+        Lock_t           lock;
+        uint8_t          flags;
+        PowerLevels_t    advPowerLevels;  // Current value of AdvertisedPowerLevels
+        uint8_t          txPowerMode;     // Firmware power levels used with setTxPower()
+        uint16_t         beaconPeriod;
+        // TLM Frame Data
+        uint8_t          tlmVersion;      // version of TLM packet
+        bool             tlmEnabled;
+        float            tlmBeaconPeriod; // how often to broadcat TLM frame, in seconds.
+        // URI Frame Data
+        uint8_t          uriDataLength;
+        UriData_t        uriData;
+        bool             uriEnabled;
+        float            uriBeaconPeriod; // how often to broadcast URIFrame, in seconds.
+        // UID Frame Data
+        UIDNamespaceID_t uidNamespaceID;  // UUID type, Namespace ID, 10B
+        UIDInstanceID_t  uidInstanceID;   // UUID type, Instance ID,  6B
+        bool             uidEnabled;
+        float            uidBeaconPeriod; // how often to broadcast UID Frame, in seconds.
+    };
+
+    /**
+     * @param[ref]    ble
+     *                    BLEDevice object for the underlying controller.
+     * @param[in/out] paramsIn
+     *                    Reference to application-visible beacon state, loaded
+     *                    from persistent storage at startup.
+     * @param[in]     defaultAdvPowerLevelsIn
+     *                    Default power-levels array; applies only if the resetToDefaultsFlag is true.
+     */
+    EddystoneConfigService(BLEDevice     &bleIn,
+                           Params_t      &paramsIn,
+                           PowerLevels_t &defaultAdvPowerLevelsIn,
+                           PowerLevels_t &radioPowerLevelsIn) :
+        ble(bleIn),
+        params(paramsIn),       // Initialize URL Data
+        defaultAdvPowerLevels(defaultAdvPowerLevelsIn),
+        radioPowerLevels(radioPowerLevelsIn),
+        initSucceeded(false),
+        resetFlag(),
+        defaultUidNamespaceID(), // Initialize UID Data
+        defaultUidInstanceID(),
+        defaultUidPower(defaultAdvPowerLevelsIn[params.txPowerMode]),
+        uidIsSet(false),
+        defaultUriDataLength(),
+        defaultUriData(),
+        defaultUrlPower(defaultAdvPowerLevelsIn[params.txPowerMode]),
+        urlIsSet(false),
+        tlmIsSet(false),
+        lockedStateChar(UUID_LOCK_STATE_CHAR, &params.lockedState),
+        lockChar(UUID_LOCK_CHAR, &params.lock),
+        uriDataChar(UUID_URI_DATA_CHAR, params.uriData, 0, URI_DATA_MAX,
+                    GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE),
+        unlockChar(UUID_UNLOCK_CHAR, &params.lock),
+        flagsChar(UUID_FLAGS_CHAR, &params.flags),
+        advPowerLevelsChar(UUID_ADV_POWER_LEVELS_CHAR, &params.advPowerLevels),
+        txPowerModeChar(UUID_TX_POWER_MODE_CHAR, &params.txPowerMode),
+        beaconPeriodChar(UUID_BEACON_PERIOD_CHAR, &params.beaconPeriod),
+        resetChar(UUID_RESET_CHAR, &resetFlag) {
+        // set eddystone as not configured yet. Used to exit config before timeout if GATT services are written to.
+        params.isConfigured = false;
+
+        lockChar.setWriteAuthorizationCallback(this, &EddystoneConfigService::lockAuthorizationCallback);
+        unlockChar.setWriteAuthorizationCallback(this, &EddystoneConfigService::unlockAuthorizationCallback);
+        uriDataChar.setWriteAuthorizationCallback(this, &EddystoneConfigService::uriDataWriteAuthorizationCallback);
+        flagsChar.setWriteAuthorizationCallback(this, &EddystoneConfigService::basicAuthorizationCallback<uint8_t>);
+        advPowerLevelsChar.setWriteAuthorizationCallback(this, &EddystoneConfigService::basicAuthorizationCallback<PowerLevels_t>);
+        txPowerModeChar.setWriteAuthorizationCallback(this, &EddystoneConfigService::powerModeAuthorizationCallback);
+        beaconPeriodChar.setWriteAuthorizationCallback(this, &EddystoneConfigService::basicAuthorizationCallback<uint16_t>);
+        resetChar.setWriteAuthorizationCallback(this, &EddystoneConfigService::basicAuthorizationCallback<uint8_t>);
+
+        static GattCharacteristic *charTable[] = {
+            &lockedStateChar, &lockChar, &unlockChar, &uriDataChar,
+            &flagsChar, &advPowerLevelsChar, &txPowerModeChar, &beaconPeriodChar, &resetChar
+        };
+
+        GattService configService(UUID_URI_BEACON_SERVICE, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));
+
+        ble.addService(configService);
+        ble.onDataWritten(this, &EddystoneConfigService::onDataWrittenCallback);
+    }
+
+    /**
+     * @brief Start EddystoneConfig advertising. This function should be called
+     * after the EddystoneConfig constructor and after all the frames have been added.
+     *
+     * @paramsP[in]   resetToDefaultsFlag
+     *                    Applies to the state of the 'paramsIn' parameter.
+     *                    If true, it indicates that paramsIn is potentially
+     *                    un-initialized, and default values should be used
+     *                    instead. Otherwise, paramsIn overrides the defaults.
+     */
+    void start(bool resetToDefaultsFlag){
+        INFO("reset to defaults flag = %d", resetToDefaultsFlag);
+        if (!resetToDefaultsFlag && (params.uriDataLength > URI_DATA_MAX)) {
+            INFO("Reset to Defaults triggered");
+            resetToDefaultsFlag = true;
+        }
+
+        if (resetToDefaultsFlag) {
+            resetToDefaults();
+        } else {
+            updateCharacteristicValues();
+        }
+
+        setupEddystoneConfigAdvertisements(); /* Setup advertising for the configService. */
+        initSucceeded = true;
+    }
+
+    /*
+    * Check if eddystone initialized successfully
+    */
+    bool initSuccessfully(void) const {
+        return initSucceeded;
+    }
+
+    /*
+    * @brief Function to update the default values for the TLM frame. Only applied if Reset Defaults is applied.
+    *
+    * @param[in] tlmVersionIn     Version of the TLM frame being used
+    * @param[in] advPeriodInMin how long between TLM frames being advertised, this is measured in minutes.
+    *
+    */
+    void setDefaultTLMFrameData(uint8_t tlmVersionIn = 0, float advPeriodInSec = 60){
+        DBG("Setting Default TLM Data, version = %d, advPeriodInMind= %f", tlmVersionIn, advPeriodInSec);
+        defaultTlmVersion   = tlmVersionIn;
+        TlmBatteryVoltage   = 0;
+        TlmBeaconTemp       = 0;
+        TlmPduCount         = 0;
+        TlmTimeSinceBoot    = 0;
+        defaultTlmAdvPeriod = advPeriodInSec;
+        tlmIsSet            = true; // flag to add this to eddystone service when config is done
+    }
+
+    /*
+    * @brief Function to update the default values for the URI frame. Only applied if Reset Defaults is applied.
+    *
+    * @param[in] uriIn      url to advertise
+    * @param[in] advPeriod  how long to advertise the url for, measured in number of ADV frames.
+    *
+    */
+    void setDefaultURIFrameData(const char *uriIn, float advPeriod = 1){
+        DBG("Setting Default URI Data");
+        // Set URL Frame
+        EddystoneService::encodeURL(uriIn, defaultUriData, defaultUriDataLength);   // encode URL to URL Formatting
+        if (defaultUriDataLength > URI_DATA_MAX) {
+            return;
+        }
+        INFO("\t  URI input = %s : %d", uriIn, defaultUriDataLength);
+        INFO("\t default URI = %s : %d ", defaultUriData, defaultUriDataLength );
+        defaultUriAdvPeriod = advPeriod;
+        urlIsSet            = true; // flag to add this to eddystone service when config is done
+    }
+
+    /*
+    * @brief Function to update the default values for the UID frame. Only applied if Reset Defaults is applied.
+    *
+    * @param[in] namespaceID 10Byte Namespace ID
+    * @param[in] instanceID  6Byte Instance ID
+    * @param[in] advPeriod   how long to advertise the URL for, measured in the number of adv frames.
+    *
+    */
+    void setDefaultUIDFrameData(UIDNamespaceID_t *namespaceID, UIDInstanceID_t *instanceID, float advPeriod = 10){
+        //Set UID frame
+        DBG("Setting default UID Data");
+        memcpy(defaultUidNamespaceID, namespaceID, UID_NAMESPACEID_SIZE);
+        memcpy(defaultUidInstanceID,  instanceID,  UID_INSTANCEID_SIZE);
+        defaultUidAdvPeriod = advPeriod;
+        uidIsSet            = true; // flag to add this to eddystone service when config is done
+    }
+
+    /* Start out by advertising the configService for a limited time after
+     * startup; and switch to the normal non-connectible beacon functionality
+     * afterwards. */
+    void setupEddystoneConfigAdvertisements() {
+        const char DEVICE_NAME[] = "eddystone Config";
+
+        ble.clearAdvertisingPayload();
+
+        ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
+
+        // UUID is in different order in the ADV frame (!)
+        uint8_t reversedServiceUUID[sizeof(UUID_URI_BEACON_SERVICE)];
+        for (unsigned int i = 0; i < sizeof(UUID_URI_BEACON_SERVICE); i++) {
+            reversedServiceUUID[i] = UUID_URI_BEACON_SERVICE[sizeof(UUID_URI_BEACON_SERVICE) - i - 1];
+        }
+        ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_128BIT_SERVICE_IDS, reversedServiceUUID, sizeof(reversedServiceUUID));
+        ble.accumulateAdvertisingPayload(GapAdvertisingData::GENERIC_TAG);
+        ble.accumulateScanResponse(GapAdvertisingData::COMPLETE_LOCAL_NAME, reinterpret_cast<const uint8_t *>(&DEVICE_NAME), sizeof(DEVICE_NAME));
+        ble.accumulateScanResponse(
+            GapAdvertisingData::TX_POWER_LEVEL,
+            reinterpret_cast<uint8_t *>(&defaultAdvPowerLevels[EddystoneConfigService::TX_POWER_MODE_LOW]),
+            sizeof(uint8_t));
+
+        ble.setTxPower(radioPowerLevels[params.txPowerMode]);
+        ble.setDeviceName(reinterpret_cast<const uint8_t *>(&DEVICE_NAME));
+        ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
+        ble.setAdvertisingInterval(GapAdvertisingParams::MSEC_TO_ADVERTISEMENT_DURATION_UNITS(ADVERTISING_INTERVAL_MSEC));
+    }
+
+    /*
+    *   This function actually impliments the Eddystone Beacon service. It can be called with the help of the wrapper function
+    *   to load saved config params, or it can be called explicitly to reset the eddystone beacon to hardcoded values on each reset.
+    *
+    */
+    void setupEddystoneAdvertisements() {
+        DBG("Switching Config -> adv");
+        // Save params to storage
+        extern void saveURIBeaconConfigParams(const Params_t *paramsP); /* forward declaration; necessary to avoid a circular dependency. */
+        saveURIBeaconConfigParams(&params);
+        INFO("Saved Params to Memory.")
+        // Setup Eddystone Service
+        static EddystoneService eddyServ(ble, params.beaconPeriod, radioPowerLevels[params.txPowerMode]);
+        // Set configured frames (TLM,UID,URI...etc)
+        if (params.tlmEnabled) {
+            eddyServ.setTLMFrameData(params.tlmVersion, params.tlmBeaconPeriod);
+        }
+        if (params.uriEnabled) {
+            eddyServ.setURLFrameData(params.advPowerLevels[params.txPowerMode], (const char *) params.uriData, params.uriBeaconPeriod);
+        }
+        if (params.uidEnabled) {
+            eddyServ.setUIDFrameData(params.advPowerLevels[params.txPowerMode],
+                                     (uint8_t *)params.uidNamespaceID,
+                                     (uint8_t *)params.uidInstanceID,
+                                     params.uidBeaconPeriod);
+        }
+        // Start Advertising the eddystone service.
+        eddyServ.start();
+    }
+
+private:
+    /*
+     * 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 onDataWrittenCallback(const GattWriteCallbackParams *writeParams) {
+        uint16_t handle = writeParams->handle;
+
+        if (handle == lockChar.getValueHandle()) {
+            // Validated earlier
+            memcpy(params.lock, writeParams->data, sizeof(Lock_t));
+            // Set the state to be locked by the lock code (note: zeros are a valid lock)
+            params.lockedState = true;
+            INFO("Device Locked");
+        } else if (handle == unlockChar.getValueHandle()) {
+            // Validated earlier
+            params.lockedState = false;
+            INFO("Device Unlocked");
+        } else if (handle == uriDataChar.getValueHandle()) {
+            params.uriDataLength = writeParams->len;
+            memset(params.uriData, 0x00, URI_DATA_MAX);                      // clear URI string
+            memcpy(params.uriData, writeParams->data, params.uriDataLength); // set URI string
+            params.uriEnabled = true;
+            INFO("URI = %s, URILen = %d", writeParams->data, writeParams->len);
+        } else if (handle == flagsChar.getValueHandle()) {
+            params.flags = *(writeParams->data);
+            INFO("flagsChar = 0x%x", params.flags);
+        } else if (handle == advPowerLevelsChar.getValueHandle()) {
+            memcpy(params.advPowerLevels, writeParams->data, sizeof(PowerLevels_t));
+            INFO("PowerLevelsChar = %4x", params.advPowerLevels);
+        } else if (handle == txPowerModeChar.getValueHandle()) {
+            params.txPowerMode = *(writeParams->data);
+            INFO("TxPowerModeChar = %d", params.txPowerMode);
+        } else if (handle == beaconPeriodChar.getValueHandle()) {
+            params.beaconPeriod = *((uint16_t *)(writeParams->data));
+            INFO("BeaconPeriod = %d", params.beaconPeriod);
+
+            /* Re-map beaconPeriod to within permissible bounds if necessary. */
+            if (params.beaconPeriod != 0) {
+                bool paramsUpdated = false;
+                if (params.beaconPeriod < ble.getMinAdvertisingInterval()) {
+                    params.beaconPeriod = ble.getMinAdvertisingInterval();
+                    paramsUpdated       = true;
+                } else if (params.beaconPeriod > ble.getMaxAdvertisingInterval()) {
+                    params.beaconPeriod = ble.getMaxAdvertisingInterval();
+                    paramsUpdated       = true;
+                }
+                if (paramsUpdated) {
+                    ble.updateCharacteristicValue(beaconPeriodChar.getValueHandle(), reinterpret_cast<uint8_t *>(&params.beaconPeriod), sizeof(uint16_t));
+                }
+            }
+        } else if (handle == resetChar.getValueHandle()) {
+            INFO("Reset triggered from Config Service, resetting to defaults");
+            resetToDefaults();
+        }
+        updateCharacteristicValues();
+        params.isConfigured = true; // some configuration data has been passed, on disconnect switch to advertising mode.
+    }
+
+    /*
+     * Reset the default values.
+     */
+    void resetToDefaults(void) {
+        INFO("Resetting to defaults");
+        // General
+        params.lockedState = false;
+        memset(params.lock, 0, sizeof(Lock_t));
+        params.flags = 0x10;
+        memcpy(params.advPowerLevels, defaultAdvPowerLevels, sizeof(PowerLevels_t));
+        params.txPowerMode  = TX_POWER_MODE_LOW;
+        params.beaconPeriod = 1000;
+
+        // TLM Frame
+        params.tlmVersion      = defaultTlmVersion;
+        params.tlmBeaconPeriod = defaultTlmAdvPeriod;
+        params.tlmEnabled      = tlmIsSet;
+
+        // URL Frame
+        memcpy(params.uriData, defaultUriData, URI_DATA_MAX);
+        params.uriDataLength   = defaultUriDataLength;
+        params.uriBeaconPeriod = defaultUriAdvPeriod;
+        params.uriEnabled      = urlIsSet;
+
+        // UID Frame
+        memcpy(params.uidNamespaceID, defaultUidNamespaceID, UID_NAMESPACEID_SIZE);
+        memcpy(params.uidInstanceID,  defaultUidInstanceID,  UID_INSTANCEID_SIZE);
+        params.uidBeaconPeriod = defaultUidAdvPeriod;
+        params.uidEnabled      = uidIsSet;
+
+        updateCharacteristicValues();
+    }
+
+    /*
+     * Internal helper function used to update the GATT database following any
+     * change to the internal state of the service object.
+     */
+    void updateCharacteristicValues(void) {
+        ble.updateCharacteristicValue(lockedStateChar.getValueHandle(), &params.lockedState, 1);
+        ble.updateCharacteristicValue(uriDataChar.getValueHandle(), params.uriData, params.uriDataLength);
+        ble.updateCharacteristicValue(flagsChar.getValueHandle(), &params.flags, 1);
+        ble.updateCharacteristicValue(beaconPeriodChar.getValueHandle(),
+                                      reinterpret_cast<uint8_t *>(&params.beaconPeriod), sizeof(uint16_t));
+        ble.updateCharacteristicValue(txPowerModeChar.getValueHandle(), &params.txPowerMode, 1);
+        ble.updateCharacteristicValue(advPowerLevelsChar.getValueHandle(),
+                                      reinterpret_cast<uint8_t *>(params.advPowerLevels), sizeof(PowerLevels_t));
+    }
+
+private:
+    void lockAuthorizationCallback(GattWriteAuthCallbackParams *authParams) {
+        if (params.lockedState) {
+            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 unlockAuthorizationCallback(GattWriteAuthCallbackParams *authParams) {
+        if ((!params.lockedState) && (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, params.lock, sizeof(Lock_t)) != 0) {
+            authParams->authorizationReply = AUTH_CALLBACK_REPLY_ATTERR_INSUF_AUTHORIZATION;
+        } else {
+            authParams->authorizationReply = AUTH_CALLBACK_REPLY_SUCCESS;
+        }
+    }
+
+    void uriDataWriteAuthorizationCallback(GattWriteAuthCallbackParams *authParams) {
+        if (params.lockedState) {
+            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 powerModeAuthorizationCallback(GattWriteAuthCallbackParams *authParams) {
+        if (params.lockedState) {
+            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 basicAuthorizationCallback(GattWriteAuthCallbackParams *authParams) {
+        if (params.lockedState) {
+            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;
+        }
+    }
+
+    BLEDevice                                  &ble;
+    Params_t                                   &params;
+    Ticker                                     timeSinceBootTick;
+    Timeout                                    switchFrame;
+    // Default value that is restored on reset
+    PowerLevels_t                              &defaultAdvPowerLevels; // this goes into the advertising frames (radio power measured at 1m from device)
+    PowerLevels_t                              &radioPowerLevels;      // this configures the power levels of the radio
+    uint8_t                                    lockedState;
+    bool                                       initSucceeded;
+    uint8_t                                    resetFlag;
+    bool                                       switchFlag;
+
+    //UID Default value that is restored on reset
+    UIDNamespaceID_t                           defaultUidNamespaceID;
+    UIDInstanceID_t                            defaultUidInstanceID;
+    float                                      defaultUidAdvPeriod;
+    int8_t                                     defaultUidPower;
+    uint16_t                                   uidRFU;
+    bool                                       uidIsSet;
+
+    //URI  Default value that is restored on reset
+    uint8_t                                    defaultUriDataLength;
+    UriData_t                                  defaultUriData;
+    int8_t                                     defaultUrlPower;
+    float                                      defaultUriAdvPeriod;
+    bool                                       urlIsSet;
+
+    //TLM  Default value that is restored on reset
+    uint8_t                                    defaultTlmVersion;
+    float                                      defaultTlmAdvPeriod;
+    volatile uint16_t                          TlmBatteryVoltage;
+    volatile uint16_t                          TlmBeaconTemp;
+    volatile uint32_t                          TlmPduCount;
+    volatile uint32_t                          TlmTimeSinceBoot;
+    bool                                       tlmIsSet;
+
+    ReadOnlyGattCharacteristic<uint8_t>        lockedStateChar;
+    WriteOnlyGattCharacteristic<Lock_t>        lockChar;
+    GattCharacteristic                         uriDataChar;
+    WriteOnlyGattCharacteristic<Lock_t>        unlockChar;
+    ReadWriteGattCharacteristic<uint8_t>       flagsChar;
+    ReadWriteGattCharacteristic<PowerLevels_t> advPowerLevelsChar;
+    ReadWriteGattCharacteristic<uint8_t>       txPowerModeChar;
+    ReadWriteGattCharacteristic<uint16_t>      beaconPeriodChar;
+    WriteOnlyGattCharacteristic<uint8_t>       resetChar;
+};
+
+#endif  // SERVICES_EDDYSTONE_BEACON_CONFIG_SERVICE_H_
diff --git a/ble/services/EddystoneService.h b/ble/services/EddystoneService.h
index 2d54095..dcf0eaf 100644
--- a/ble/services/EddystoneService.h
+++ b/ble/services/EddystoneService.h
@@ -19,25 +19,37 @@
 
 #include "ble/BLE.h"
 #include "mbed.h"
-
+#include "CircularBuffer.h"
 static const uint8_t BEACON_EDDYSTONE[] = {0xAA, 0xFE};
 
 //Debug is disabled by default
 #if 0
-#define DBG(x, ...)  printf("[EddyStone: DBG]"x" \t[%s,%d]\r\n", ##__VA_ARGS__,__FILE__,__LINE__);
-#define WARN(x, ...) printf("[EddyStone: WARN]"x" \t[%s,%d]\r\n", ##__VA_ARGS__,__FILE__,__LINE__);
-#define ERR(x, ...)  printf("[EddyStone: ERR]"x" \t[%s,%d]\r\n", ##__VA_ARGS__,__FILE__,__LINE__);
-#else
+#define DBG(MSG, ...)  printf("[EddyStone: DBG]" MSG " \t[%s,%d]\r\n", \
+                            ## __VA_ARGS__,                            \
+                            __FILE__,                                  \
+                            __LINE__);
+#define WARN(MSG, ...) printf("[EddyStone: WARN]" MSG " \t[%s,%d]\r\n", \
+                            ## __VA_ARGS__,                             \
+                            __FILE__,                                   \
+                            __LINE__);
+#define ERR(MSG, ...)  printf("[EddyStone: ERR]" MSG " \t[%s,%d]\r\n", \
+                            ## __VA_ARGS__,                            \
+                            __FILE__,                                  \
+                            __LINE__);
+#else // if 0
 #define DBG(x, ...) //wait_us(10);
 #define WARN(x, ...) //wait_us(10);
 #define ERR(x, ...)
-#endif
+#endif // if 0
 
 #if 0
-#define INFO(x, ...)  printf("[EddyStone: INFO]"x" \t[%s,%d]\r\n", ##__VA_ARGS__,__FILE__,__LINE__);
-#else
+#define INFO(x, ...)  printf("[EddyStone: INFO]"x " \t[%s,%d]\r\n", \
+                             ## __VA_ARGS__,                        \
+                             __FILE__,                              \
+                             __LINE__);
+#else // if 0
 #define INFO(x, ...)
-#endif
+#endif // if 0
 
 /**
 * @class Eddystone
@@ -48,19 +60,21 @@ static const uint8_t BEACON_EDDYSTONE[] = {0xAA, 0xFE};
 class EddystoneService
 {
 public:
-    /**
-     * @brief Transmission Power Modes for UriBeacon
-     */
+    enum FrameTypes {
+        NONE,
+        url,
+        uid,
+        tlm
+    };
 
-    static const int ADVERTISING_INTERVAL_MSEC = 1000;  // Advertising interval for config service.
     static const int SERVICE_DATA_MAX = 31;             // Maximum size of service data in ADV packets
 
     // There are currently 3 subframes defined, URI, UID, and TLM
 #define EDDYSTONE_MAX_FRAMETYPE 3
     void (*frames[EDDYSTONE_MAX_FRAMETYPE])(uint8_t *, uint32_t);
-    uint8_t frameIndex;
     static const int URI_DATA_MAX = 18;
     typedef uint8_t  UriData_t[URI_DATA_MAX];
+    CircularBuffer<FrameTypes, EDDYSTONE_MAX_FRAMETYPE> overflow;
 
     // UID Frame Type subfields
     static const int UID_NAMESPACEID_SIZE = 10;
@@ -76,71 +90,98 @@ public:
     static const uint8_t FRAME_SIZE_TLM = 14; // TLM frame is a constant 14Bytes
     static const uint8_t FRAME_SIZE_UID = 20; // includes RFU bytes
 
-    /*
-    *  Set Eddystone UID Frame information.
-    *  @param[in] power   TX Power in dB measured at 0 meters from the device. Range of -100 to +20 dB.
-    *  @param namespaceID 10B namespace ID
-    *  @param instanceID  6B instance ID
-    *  @param RFU         2B of RFU, initialized to 0x0000 and not broadcast, included for future reference.
-    *
-    */
-    void setUIDFrameData(int8_t power, UIDNamespaceID_t namespaceID, UIDInstanceID_t instanceID, uint16_t RFU = 0x0000) {
-        if(power > 20) {
+    /**
+     *  Set Eddystone UID Frame information.
+     *
+     *  @param[in] power       TX Power in dB measured at 0 meters from the device. Range of -100 to +20 dB.
+     *  @param[in] namespaceID 10B namespace ID
+     *  @param[in] instanceID  6B instance ID
+     *  @param[in] RFU         2B of RFU, initialized to 0x0000 and not broadcast, included for future reference.
+     */
+    void setUIDFrameData(int8_t           power,
+                         UIDNamespaceID_t namespaceID,
+                         UIDInstanceID_t  instanceID,
+                         uint32_t         uidAdvPeriodIn,
+                         uint16_t         RFU = 0x0000) {
+        if (0 == uidAdvPeriodIn) {
+            uidIsSet = false;
+            return;
+        }
+        if (power > 20) {
             power = 20;
         }
-        if(power < -100) {
+        if (power < -100) {
             power = -100;
         }
+
         defaultUidPower = power;
         memcpy(defaultUidNamespaceID, namespaceID, UID_NAMESPACEID_SIZE);
         memcpy(defaultUidInstanceID,  instanceID,  UID_INSTANCEID_SIZE);
-        uidRFU = (uint16_t)RFU; // this is probably bad form, but it doesnt really matter yet.
-        return;
+        uidRFU       = (uint16_t)RFU; // this is probably bad form, but it doesn't really matter yet.
+        uidAdvPeriod = uidAdvPeriodIn;
+        uidIsSet     = true;          // set toggle to advertise UID frames
     }
 
     /*
     *  Construct UID frame from private variables
     *  @param[in/out] Data pointer to array to store constructed frame in
-    *  @param[in] maxSize number of bytes left in array, effectively how much emtpy space is available to write to
+    *  @param[in] maxSize number of bytes left in array, effectively how much empty space is available to write to
     *  @return number of bytes used. negative number indicates error message.
     */
-    int constructUIDFrame(uint8_t * Data, uint8_t maxSize) {
+    unsigned constructUIDFrame(uint8_t *Data, uint8_t maxSize) {
+        unsigned index = 0;
 
-        int index = 0;
         Data[index++] = FRAME_TYPE_UID;                     // 1B  Type
-        if(defaultUidPower > 20) {
-            defaultUidPower = 20;   // enforce range of vaild values.
+
+        if (defaultUidPower > 20) {
+            defaultUidPower = 20;                           // enforce range of vaild values.
         }
-        if(defaultUidPower < -100) {
+        if (defaultUidPower < -100) {
             defaultUidPower = -100;
         }
         Data[index++] = defaultUidPower;                    // 1B  Power @ 0meter
-        for(int x = 0; x < UID_NAMESPACEID_SIZE; x++) {     // 10B Namespce ID
+
+        DBG("UID NamespaceID = '0x");
+        for (size_t x = 0; x < UID_NAMESPACEID_SIZE; x++) { // 10B Namespace ID
             Data[index++] = defaultUidNamespaceID[x];
+            DBG("%x,", defaultUidNamespaceID[x]);
         }
-        for(int x = 0; x< UID_INSTANCEID_SIZE; x++) {       // 6B  Instance ID
+        DBG("'\r\n");
+
+        DBG("UID InstanceID = '0x");
+        for (size_t x = 0; x< UID_INSTANCEID_SIZE; x++) {   // 6B  Instance ID
             Data[index++] = defaultUidInstanceID[x];
+            DBG("%x,", defaultUidInstanceID[x]);
         }
-        if(0 != uidRFU) {                                // 2B RFU, include if non-zero, otherwise ignore
+        DBG("'\r\n");
+
+        if (0 != uidRFU) {                                  // 2B RFU, include if non-zero, otherwise ignore
             Data[index++] = (uint8_t)(uidRFU >> 0);
             Data[index++] = (uint8_t)(uidRFU >> 8);
         }
-        DBG("construcUIDFrame %d, %d",maxSize,index);
+        DBG("construcUIDFrame %d, %d", maxSize, index);
         return index;
     }
 
-    /*
-    *  Set Eddystone URL Frame information.
-    *  @param[in] power   TX Power in dB measured at 0 meters from the device.
-    *  @param url         URL to encode
-    *  @return            false on success, true on failure.
-    */
-    bool setURLFrameData(int8_t power, const char * url) {
-        defaultUrlPower = power;
-        encodeURL(url, defaultUriData, defaultUriDataLength); // encode URL to URL Formatting
-        if (defaultUriDataLength > URI_DATA_MAX) {
-            return true; // error, URL is too big
+    /**
+     *  Set Eddystone URL Frame information.
+     *  @param[in] power          TX Power in dB measured at 0 meters from the device.
+     *  @param[in] url            URL to encode
+     *  @param[in] urlAdvPeriodIn How long to advertise the URL frame (measured in # of adv periods)
+     *  @return false on success, true on failure.
+     */
+    bool setURLFrameData(int8_t power, const char *urlIn, uint32_t urlAdvPeriodIn) {
+        if (0 == urlAdvPeriodIn) {
+            urlIsSet = false;
+            return false;
         }
+        defaultUrlPower = power;
+        encodeURL(urlIn, defaultUriData, defaultUriDataLength); // encode URL to URL Formatting
+        if (defaultUriDataLength > URI_DATA_MAX) {
+            return true;                                        // error, URL is too big
+        }
+        urlAdvPeriod = urlAdvPeriodIn;
+        urlIsSet     = true;
         return false;
     }
 
@@ -150,31 +191,42 @@ public:
     *  @param[in] maxSize number of bytes left in array, effectively how much emtpy space is available to write to
     *  @return number of bytes used. negative number indicates error message.
     */
-    int constructURLFrame(uint8_t * Data, uint8_t maxSize) {
+    int constructURLFrame(uint8_t *Data, uint8_t maxSize) {
         int index = 0;
         Data[index++] = FRAME_TYPE_URL;                     // 1B  Type
         Data[index++] = defaultUrlPower;                    // 1B  TX Power
-        for(int x = 0; x < defaultUriDataLength; x++) {     // 18B of URL Prefix + encoded URL
+        for (int x = 0; x < defaultUriDataLength; x++) {    // 18B of URL Prefix + encoded URL
             Data[index++] = defaultUriData[x];
         }
-        DBG("constructURLFrame: %d, %d",maxSize,index);
+        DBG("constructURLFrame: %d, %d", maxSize, index);
         return index;
     }
 
     /*
     *  Set Eddystone TLM Frame information.
     *  @param[in] Version    of the TLM beacon data format
+    *  @param[in] advPeriod  how often to advertise the TLM frame for (in minutes)
     *  @param batteryVoltage in milivolts
     *  @param beaconTemp     in 8.8 floating point notation
     *
     */
-    void setTLMFrameData(uint8_t version, uint16_t batteryVoltage, uint16_t beaconTemp, uint32_t pduCount = 0, uint32_t timeSinceBoot = 0) {
-        TlmVersion = version;
+    void setTLMFrameData(uint8_t  version        = 0,
+                         uint32_t advPeriod      = 60,
+                         uint16_t batteryVoltage = 0,
+                         uint16_t beaconTemp     = 0,
+                         uint32_t pduCount       = 0,
+                         uint32_t timeSinceBoot  = 0) {
+        if (0 == advPeriod) {
+            tlmIsSet = false;
+            return;
+        }
+        TlmVersion        = version;
         TlmBatteryVoltage = batteryVoltage;
-        TlmBeaconTemp = beaconTemp;
-        TlmPduCount = pduCount; // reset
-        TlmTimeSinceBoot = timeSinceBoot; // reset
-        return;
+        TlmBeaconTemp     = beaconTemp;
+        TlmPduCount       = pduCount;      // reset
+        TlmTimeSinceBoot  = timeSinceBoot; // reset
+        TlmAdvPeriod      = advPeriod;
+        tlmIsSet          = true;          // TLM Data has been enabled
     }
 
     /*
@@ -183,23 +235,23 @@ public:
     *  @param[in] maxSize number of bytes left in array, effectively how much emtpy space is available to write to
     *  @return number of bytes used. negative number indicates error message.
     */
-    int constructTLMFrame(uint8_t * Data, uint8_t maxSize) {
+    int constructTLMFrame(uint8_t *Data, uint8_t maxSize) {
         int index = 0;
         Data[index++] = FRAME_TYPE_TLM;                    // Eddystone frame type = Telemetry
         Data[index++] = TlmVersion;                        // TLM Version Number
-        Data[index++] = (uint8_t)(TlmBatteryVoltage>>8);   // Battery Voltage[0]
-        Data[index++] = (uint8_t)(TlmBatteryVoltage>>0);   // Battery Voltage[1]
-        Data[index++] = (uint8_t)(TlmBeaconTemp>>8);       // Beacon Temp[0]
-        Data[index++] = (uint8_t)(TlmBeaconTemp>>0);       // Beacon Temp[1]
-        Data[index++] = (uint8_t)(TlmPduCount>>24);         // PDU Count [0]
-        Data[index++] = (uint8_t)(TlmPduCount>>16);         // PDU Count [1]
-        Data[index++] = (uint8_t)(TlmPduCount>>8);        // PDU Count [2]
-        Data[index++] = (uint8_t)(TlmPduCount>>0);        // PDU Count [3]
-        Data[index++] = (uint8_t)(TlmTimeSinceBoot>>24);    // Time Since Boot [0]
-        Data[index++] = (uint8_t)(TlmTimeSinceBoot>>16);    // Time Since Boot [1]
-        Data[index++] = (uint8_t)(TlmTimeSinceBoot>>8);   // Time Since Boot [2]
-        Data[index++] = (uint8_t)(TlmTimeSinceBoot>>0);   // Time Since Boot [3]
-        DBG("constructURLFrame: %d, %d",maxSize,index);
+        Data[index++] = (uint8_t)(TlmBatteryVoltage >> 8); // Battery Voltage[0]
+        Data[index++] = (uint8_t)(TlmBatteryVoltage >> 0); // Battery Voltage[1]
+        Data[index++] = (uint8_t)(TlmBeaconTemp >> 8);     // Beacon Temp[0]
+        Data[index++] = (uint8_t)(TlmBeaconTemp >> 0);     // Beacon Temp[1]
+        Data[index++] = (uint8_t)(TlmPduCount >> 24);      // PDU Count [0]
+        Data[index++] = (uint8_t)(TlmPduCount >> 16);      // PDU Count [1]
+        Data[index++] = (uint8_t)(TlmPduCount >> 8);       // PDU Count [2]
+        Data[index++] = (uint8_t)(TlmPduCount >> 0);       // PDU Count [3]
+        Data[index++] = (uint8_t)(TlmTimeSinceBoot >> 24); // Time Since Boot [0]
+        Data[index++] = (uint8_t)(TlmTimeSinceBoot >> 16); // Time Since Boot [1]
+        Data[index++] = (uint8_t)(TlmTimeSinceBoot >> 8);  // Time Since Boot [2]
+        Data[index++] = (uint8_t)(TlmTimeSinceBoot >> 0);  // Time Since Boot [3]
+        DBG("constructURLFrame: %d, %d", maxSize, index);
         return index;
     }
 
@@ -210,7 +262,6 @@ public:
     */
     void updateTlmBatteryVoltage(uint16_t voltagemv) {
         TlmBatteryVoltage = voltagemv;
-        return;
     }
 
     /*
@@ -220,7 +271,6 @@ public:
     */
     void updateTlmBeaconTemp(uint16_t temp) {
         TlmBeaconTemp = temp;
-        return;
     }
 
     /*
@@ -230,7 +280,6 @@ public:
     */
     void updateTlmPduCount(uint32_t pduCount) {
         TlmPduCount = pduCount;
-        return;
     }
 
     /*
@@ -240,7 +289,6 @@ public:
     */
     void updateTlmTimeSinceBoot(uint32_t timeSinceBoot) {
         TlmTimeSinceBoot = timeSinceBoot;
-        return;
     }
 
     /*
@@ -258,16 +306,15 @@ public:
     bool updateAdvPacket(uint8_t serviceData[], unsigned serviceDataLen) {
         // Fields from the Service
         DBG("Updating AdvFrame: %d", serviceDataLen);
-//        printf("\r\n");
-//        for(int x = 0; x<serviceDataLen; x++) {
-//            printf("%2.2x:",serviceData[x]);
-//        }
-//        printf("\r\n");
+
         ble.clearAdvertisingPayload();
+        ble.setAdvertisingType(GapAdvertisingParams::ADV_NON_CONNECTABLE_UNDIRECTED);
+        ble.setAdvertisingInterval(100);
         ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
         ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, BEACON_EDDYSTONE, sizeof(BEACON_EDDYSTONE));
         ble.accumulateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, serviceData, serviceDataLen);
 
+
         return true;
     }
 
@@ -277,45 +324,124 @@ public:
     *   This function exists because of time constraints in the radioNotificationCallback, so it is effectively
     *   broken up into two functions.
     */
-    void swapOutFrames(void) {
-        uint8_t serviceData[SERVICE_DATA_MAX];
+    void swapOutFrames(FrameTypes frameType) {
+        uint8_t  serviceData[SERVICE_DATA_MAX];
         unsigned serviceDataLen = 0;
         //hard code in the eddystone UUID
         serviceData[serviceDataLen++] = BEACON_EDDYSTONE[0];
         serviceData[serviceDataLen++] = BEACON_EDDYSTONE[1];
 
         // if certain frames are not enabled, then skip them. Worst case TLM is always enabled
-        switch(frameIndex) {
-            case 1:
-                // URL Frame
-                if(urlIsSet) {
-                    INFO("Swapping in URL Frame: Power: %d",defaultUrlPower);
-                    serviceDataLen += constructURLFrame(serviceData+serviceDataLen,20);
-                    DBG("\t Swapping in URL Frame: len=%d ",serviceDataLen);
-                    updateAdvPacket(serviceData,serviceDataLen);
-                    switchFlag = false;
-                    frameIndex++;
-                    break;
-                }
-            case 2:
-                // UID Frame
-                if(uidIsSet) {
-                    INFO("Swapping in UID Frame: Power: %d",defaultUidPower);
-                    serviceDataLen += constructUIDFrame(serviceData+serviceDataLen,20);
-                    DBG("\t Swapping in UID Frame: len=%d",serviceDataLen);
-                    updateAdvPacket(serviceData,serviceDataLen);
-                    switchFlag = false;
-                    frameIndex++;
-                    break;
-                }
-            default:
+        switch (frameType) {
+            case tlm:
                 // TLM frame
-                INFO("Swapping in TLM Frame: version=%x, Batt=%d, Temp = %d, PDUCnt = %d, TimeSinceBoot=%d",TlmVersion, TlmBatteryVoltage, TlmBeaconTemp, TlmPduCount, TlmTimeSinceBoot);
-                serviceDataLen += constructTLMFrame(serviceData+serviceDataLen,20);
-                DBG("\t Swapping in TLM Frame: len=%d",serviceDataLen);
-                updateAdvPacket(serviceData,serviceDataLen);
-                frameIndex++;
+                if (tlmIsSet) {
+                    DBG("Swapping in TLM Frame: version=%x, Batt=%d, Temp = %d, PDUCnt = %d, TimeSinceBoot=%d",
+                        TlmVersion,
+                        TlmBatteryVoltage,
+                        TlmBeaconTemp,
+                        TlmPduCount,
+                        TlmTimeSinceBoot);
+                    serviceDataLen += constructTLMFrame(serviceData + serviceDataLen, 20);
+                    DBG("\t Swapping in TLM Frame: len=%d", serviceDataLen);
+                    updateAdvPacket(serviceData, serviceDataLen);
+                }
                 break;
+            case url:
+                // URL Frame
+                if (urlIsSet) {
+                    DBG("Swapping in URL Frame: Power: %d", defaultUrlPower);
+                    serviceDataLen += constructURLFrame(serviceData + serviceDataLen, 20);
+                    DBG("\t Swapping in URL Frame: len=%d ", serviceDataLen);
+                    updateAdvPacket(serviceData, serviceDataLen);
+                    //switchFlag = false;
+                }
+                break;
+            case uid:
+                // UID Frame
+                if (uidIsSet) {
+                    DBG("Swapping in UID Frame: Power: %d", defaultUidPower);
+                    serviceDataLen += constructUIDFrame(serviceData + serviceDataLen, 20);
+                    DBG("\t Swapping in UID Frame: len=%d", serviceDataLen);
+                    updateAdvPacket(serviceData, serviceDataLen);
+                    //switchFlag = false;
+                }
+                break;
+            default:
+                ERR("You have not initialized a Frame yet, please initialize one before starting a beacon");
+                ERR("uidIsSet = %d, urlIsSet = %d, tlmIsSet = %d", uidIsSet, urlIsSet, tlmIsSet);
+        }
+    }
+
+    /*
+    * Callback to swap in URL frame
+    */
+    void urlCallback(void) {
+        DBG("urlCallback");
+        if (false == advLock) {
+            advLock = true;
+            DBG("advLock = url")
+            frameIndex = url;
+            swapOutFrames(frameIndex);
+            ble.startAdvertising();
+        } else {
+            // Someone else is broadcasting, toss it into the overflow buffer to retransmit when free
+            INFO("URI(%d) cannot complete, %d is currently broadcasting", url, frameIndex);
+            FrameTypes x = url;
+            overflow.push(x);
+        }
+    }
+
+    /*
+    * Callback to swap in UID frame
+    */
+    void uidCallback(void) {
+        DBG("uidCallback");
+        if (false == advLock) {
+            advLock = true;
+            DBG("advLock = uid")
+            frameIndex = uid;
+            swapOutFrames(frameIndex);
+            ble.startAdvertising();
+        } else {
+            // Someone else is broadcasting, toss it into the overflow buffer to retransmit when free
+            INFO("UID(%d) cannot complete, %d is currently broadcasting", uid, frameIndex);
+            FrameTypes x = uid; // have to do this to satisfy cont vs volatile keywords... sigh...
+            overflow.push(x);
+        }
+    }
+
+    /*
+    * Callback to swap in TLM frame
+    */
+    void tlmCallback(void) {
+        DBG("tlmCallback");
+        if (false == advLock) {
+            // OK to broadcast
+            advLock = true;
+            DBG("advLock = tlm")
+            frameIndex = tlm;
+            swapOutFrames(frameIndex);
+            ble.startAdvertising();
+        } else {
+            // Someone else is broadcasting, toss it into the overflow buffer to retransmit when free
+            INFO("TLM(%d) cannot complete, %d is currently broadcasting", tlm, frameIndex);
+            FrameTypes x = tlm;
+            overflow.push(x);
+        }
+    }
+
+    void stopAdvCallback(void) {
+        if (overflow.empty()) {
+            // if nothing left to transmit, stop
+            ble.stopAdvertising();
+            advLock = false; // unlock lock
+        } else {
+            // transmit other packets at current time index
+            FrameTypes x = NONE;
+            overflow.pop(x);
+            INFO("Re-Transmitting %d", x);
+            swapOutFrames(x);
         }
     }
 
@@ -324,48 +450,15 @@ public:
     */
 #define EDDYSTONE_SWAPFRAME_DELAYMS 1
     void radioNotificationCallback(bool radioActive) {
-        //DBG("RadioNotificationCallback : %d, %d, %d, %d",radioActive,frameIndex,TlmPduCount,TlmTimeSinceBoot);
         // Update PDUCount
         TlmPduCount++;
-        frameIndex = frameIndex % EDDYSTONE_MAX_FRAMETYPE;
-
-
-        // True just before an frame is sent, fale just after a frame is sent
-        if(radioActive) {
+        // True just before an frame is sent, false just after a frame is sent
+        if (radioActive) {
             // Do Nothing
         } else {
-            // state machine to control which packet is being sent
-            switch(frameIndex) {
-                case 0: // TLM Frame
-                    switchFrame.attach_us(this, &EddystoneService::swapOutFrames, EDDYSTONE_SWAPFRAME_DELAYMS);
-                    switchFlag = true;
-                    break;
-                case 1: // URL Frame
-                    // switch out packets
-                    if(switchFlag) {
-                        switchFrame.attach_us(this, &EddystoneService::swapOutFrames, EDDYSTONE_SWAPFRAME_DELAYMS);
-                        switchFlag = false;
-                    } else {
-                        if((TlmPduCount % 10) == 0) { // every 10 adv packets switch the frame
-                            switchFlag = true;
-                        }
-                    }
-                    break;
-                case 2: // UIDFrame
-                    // switch out packets
-                    if(switchFlag ) {
-                        switchFrame.attach_us(this, &EddystoneService::swapOutFrames, EDDYSTONE_SWAPFRAME_DELAYMS);
-                        switchFlag = false;
-                    } else {
-                        if((TlmPduCount % 10) == 0) { // every 10 adv packets switch the frame
-                            switchFlag = true;
-                        }
-                    }
-                    break;
-            }
+            // Packet has been sent, disable advertising
+            stopAdv.attach_us(this, &EddystoneService::stopAdvCallback, 1);
         }
-
-        return;
     }
 
     /*
@@ -373,110 +466,106 @@ public:
     *   this function should be used in leu of the config service.
     *
     *   @param bleIn ble object used to broadcast eddystone information
-    *   @oaram beaconPeriodus is how often ble broadcasts are mde, in mili seconds
+    *   @param beaconPeriodus is how often ble broadcasts are mde, in mili seconds
     *   @param txPowerLevel sets the broadcasting power level.
-    *   @param uidNamespaceID 10Byte Namespace UUID
-    *   @param uidInstanceID  6Byte  Instance UUID
-    *   @param url shortened URL to broadcast (pass in as a string)
-    *   @param urlLen length of shortened url
-    *   @param tlmVersion version of telemetry data field to use (default to 0x00)
     *
     */
-    EddystoneService(BLEDevice       &bleIn,
-              uint16_t        beaconPeriodus = 100,
-              uint8_t         txPowerLevel = 0,
-              uint8_t *       uidNamespaceID = NULL,
-              uint8_t *       uidInstanceID = NULL,
-              const char *    url = NULL,
-              uint8_t         urlLen = 0,
-              uint8_t         tlmVersion = 0) :
-              ble(bleIn)
-    { 
-        uint8_t serviceData[SERVICE_DATA_MAX];
-        unsigned serviceDataLen = 0;
-        ERR("This function is not fully implemented yet, dont use it!!");
-        // Check optional frames, set their 'isSet' flags appropriately
-        if((uidNamespaceID != NULL) & (uidInstanceID != NULL)) {
-            uidIsSet = true;
-            setUIDFrameData(txPowerLevel,uidNamespaceID, uidInstanceID);
-        } else {
-            uidIsSet = false;
+    EddystoneService(BLEDevice &bleIn,
+                     uint16_t   beaconPeriodus = 100,
+                     uint8_t    txPowerIn      = 0) :
+        ble(bleIn),
+        advPeriodus(beaconPeriodus),
+        txPower(txPowerIn),
+        advLock(false),
+        frameIndex(NONE) {
+    }
+
+    /*
+    * @breif this function starts eddystone advertising based on configured frames.
+    */
+    void start(void) {
+        // Initialize Frame transition, start with URL to pass eddystone validator app on first try
+        if (urlIsSet) {
+            frameIndex = url;
+            urlTicker.attach(this, &EddystoneService::urlCallback, urlAdvPeriod);
+            DBG("attached urlCallback every %d seconds", urlAdvPeriod);
         }
-        if(url != NULL) {
-            urlIsSet = true;
-            setURLFrameData(txPowerLevel,url);
-        } else {
-            uidIsSet = false;
+        if (uidIsSet) {
+            frameIndex = uid;
+            uidTicker.attach(this, &EddystoneService::uidCallback, uidAdvPeriod);
+            DBG("attached uidCallback every %d seconds", uidAdvPeriod);
         }
-        // Default TLM frame to version 0x00, start all values at zero to be spec compliant.
-        setTLMFrameData(tlmVersion, 0x00,0x00);
-
-        // Initialize Frame transition
-        frameIndex = 0;
-        uidRFU = 0;
-        switchFlag = true;
-
-        /* Reinitialize the BLE stack. This will clear away the existing services and advertising state. */
-        ble.shutdown();
-        ble.init();
-        ble.setTxPower(txPowerLevel);
-        ble.setAdvertisingType(GapAdvertisingParams::ADV_NON_CONNECTABLE_UNDIRECTED);
-        ble.setAdvertisingInterval(beaconPeriodus);
-
-        // Make double sure the PDUCount and TimeSinceBoot fields are set to zero at reset
-        updateTlmPduCount(0);
-        updateTlmTimeSinceBoot(0);
-
-        // Construct TLM Frame in initial advertising.
-        serviceData[serviceDataLen++] = BEACON_EDDYSTONE[0];
-        serviceData[serviceDataLen++] = BEACON_EDDYSTONE[1];
-        serviceDataLen += constructTLMFrame(serviceData+serviceDataLen,SERVICE_DATA_MAX);
-
-        updateAdvPacket(serviceData, serviceDataLen);
-        ble.gap().startAdvertising();
-        ble.gap().onRadioNotification(this,&EddystoneService::radioNotificationCallback);
-        timeSinceBootTick.attach(this,&EddystoneService::tsbCallback,0.1); // incriment the TimeSinceBoot ticker every 0.1s
+        if (tlmIsSet) {
+            frameIndex = tlm;
+            // Make double sure the PDUCount and TimeSinceBoot fields are set to zero at reset
+            updateTlmPduCount(0);
+            updateTlmTimeSinceBoot(0);
+            timeSinceBootTick.attach(this, &EddystoneService::tsbCallback, 0.1); // incriment the TimeSinceBoot ticker every 0.1s
+            tlmTicker.attach(this, &EddystoneService::tlmCallback, TlmAdvPeriod);
+            DBG("attached tlmCallback every %d seconds", TlmAdvPeriod);
+        }
+        if (NONE == frameIndex) {
+            error("No Frames were Initialized! Please initialize a frame before starting an eddystone beacon.");
+        }
+        //uidRFU = 0;
 
+        ble.setTxPower(txPower);
+        ble.gap().onRadioNotification(this, &EddystoneService::radioNotificationCallback);
     }
 
 private:
 
-
+    // Eddystone Variables
     BLEDevice           &ble;
-    Ticker              timeSinceBootTick;
-    Timeout             switchFrame;
-// Default value that is restored on reset
-    size_t              defaultUriDataLength;
+    uint16_t            advPeriodus;
+    uint8_t             txPower;
+    Ticker              timeSinceBootTick;  // counter that counts time since boot
+    volatile bool       advLock;
+    volatile FrameTypes frameIndex;
+    Timeout             stopAdv;
+
+
+    // URI Frame Variables
+    uint8_t             defaultUriDataLength;
     UriData_t           defaultUriData;
+    int8_t              defaultUrlPower;
+    bool                urlIsSet;       // flag that enables / disable URI Frames
+    uint32_t            urlAdvPeriod;   // how long the url frame will be advertised for
+    Ticker              urlTicker;
+
+    // UID Frame Variables
     UIDNamespaceID_t    defaultUidNamespaceID;
     UIDInstanceID_t     defaultUidInstanceID;
     int8_t              defaultUidPower;
-    int8_t              defaultUrlPower;
     uint16_t            uidRFU;
-    bool                uidIsSet;
-    bool                urlIsSet;
-    bool switchFlag;
+    bool                uidIsSet;       // flag that enables / disable UID Frames
+    uint32_t            uidAdvPeriod;   // how long the uid frame will be advertised for
+    Ticker              uidTicker;
 
-// Private Variables for Telemetry Data
-    uint8_t                      TlmVersion;
-    volatile uint16_t            TlmBatteryVoltage;
-    volatile uint16_t            TlmBeaconTemp;
-    volatile uint32_t            TlmPduCount;
-    volatile uint32_t            TlmTimeSinceBoot;
+    // TLM Frame Variables
+    uint8_t             TlmVersion;
+    volatile uint16_t   TlmBatteryVoltage;
+    volatile uint16_t   TlmBeaconTemp;
+    volatile uint32_t   TlmPduCount;
+    volatile uint32_t   TlmTimeSinceBoot;
+    bool                tlmIsSet;          // flag that enables / disables TLM frames
+    uint32_t            TlmAdvPeriod;      // number of minutes between adv frames
+    Ticker              tlmTicker;
 
 public:
     /*
      *  Encode a human-readable URI into the binary format defined by URIBeacon spec (https://github.com/google/uribeacon/tree/master/specification).
      */
-    static void encodeURL(const char *uriDataIn, UriData_t uriDataOut, size_t &sizeofURIDataOut) {
-        const char *prefixes[] = {
+    static void encodeURL(const char *uriDataIn, UriData_t uriDataOut, uint8_t &sizeofURIDataOut) {
+        DBG("Encode URL = %s", uriDataIn);
+        const char  *prefixes[] = {
             "http://www.",
             "https://www.",
             "http://",
             "https://",
         };
         const size_t NUM_PREFIXES = sizeof(prefixes) / sizeof(char *);
-        const char *suffixes[] = {
+        const char  *suffixes[]   = {
             ".com/",
             ".org/",
             ".edu/",
@@ -528,6 +617,7 @@ public:
                 }
             }
             /* This is the default case where we've got an ordinary character which doesn't match a suffix. */
+            INFO("Encoding URI: No Suffix Found");
             if (i == NUM_SUFFIXES) {
                 uriDataOut[sizeofURIDataOut++] = *uriDataIn;
                 ++uriDataIn;
diff --git a/module.json b/module.json
index ab75196..1230e27 100644
--- a/module.json
+++ b/module.json
@@ -1,6 +1,6 @@
 {
   "name": "ble",
-  "version": "0.4.7",
+  "version": "0.4.8",
   "description": "The BLE module offers a high level abstraction for using Bluetooth Low Energy on multiple platforms.",
   "keywords": [
     "Bluetooth",
@@ -30,4 +30,4 @@
       "mbed-drivers": "*"
     }
   }
-}
\ No newline at end of file
+}
diff --git a/source/BLE.cpp b/source/BLE.cpp
index 26d9dc7..28bfd0b 100644
--- a/source/BLE.cpp
+++ b/source/BLE.cpp
@@ -36,3 +36,85 @@ BLE::init()
 
     return BLE_ERROR_NONE;
 }
+
+/**
+ * BLE::Instance() and BLE constructor rely upon a static array of initializers
+ * to create actual BLE transport instances. A description of these instances
+ * and initializers is supposed to be put in some .json file contributing to
+ * yotta's configuration (typically in the target definition described by
+ * target.json). Here's a sample:
+ *
+ *  "config": {
+ *    ...
+ *    "ble_instances": {
+ *      "count": 1,
+ *      "0" : {
+ *        "initializer" : "createBLEInstance"
+ *      }
+ *    }
+ *    ...
+ *  }
+ *
+ * The following macros result in translating the above config into a static
+ * array: instanceConstructors.
+ */
+#ifdef YOTTA_CFG_BLE_INSTANCES_COUNT
+#define CONCATENATE(A, B) A ## B
+#define EXPAND(X) X /* this adds a level of indirection needed to allow macro-expansion following a token-paste operation (see use of CONCATENATE() below). */
+
+#define INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_1 YOTTA_CFG_BLE_INSTANCES_0_INITIALIZER
+#define INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_2 INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_1, YOTTA_CFG_BLE_INSTANCES_1_INITIALIZER
+#define INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_3 INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_2, YOTTA_CFG_BLE_INSTANCES_2_INITIALIZER
+#define INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_4 INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_3, YOTTA_CFG_BLE_INSTANCES_3_INITIALIZER
+#define INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_5 INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_4, YOTTA_CFG_BLE_INSTANCES_4_INITIALIZER
+/* ... add more of the above if ever needed */
+
+#define INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS(N) EXPAND(CONCATENATE(INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS_, N))
+#elif !defined(INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS)
+/*
+ * The following applies when building without yotta. By default BLE_API provides
+ * a trivial initializer list containing a single constructor: createBLEInstance.
+ * This may be overridden.
+ */
+#define INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS createBLEInstance
+#endif /* YOTTA_CFG_BLE_INSTANCES_COUNT */
+
+typedef BLEInstanceBase *(*InstanceConstructor_t)(void);
+static const InstanceConstructor_t instanceConstructors[BLE::NUM_INSTANCES] = {
+#ifndef YOTTA_CFG_BLE_INSTANCES_COUNT
+    INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS
+#else
+    INITIALIZER_LIST_FOR_INSTANCE_CONSTRUCTORS(YOTTA_CFG_BLE_INSTANCES_COUNT)
+#endif
+};
+
+BLE &
+BLE::Instance(InstanceID_t id)
+{
+    static BLE *singletons[NUM_INSTANCES];
+    if (id < NUM_INSTANCES) {
+        if (singletons[id] == NULL) {
+            singletons[id] = new BLE(id); /* This object will never be freed. */
+        }
+
+        return *singletons[id];
+    }
+
+    /* we come here only in the case of a bad interfaceID. */
+    static BLE badSingleton(NUM_INSTANCES /* this is a bad index; and will result in a NULL transport. */);
+    return badSingleton;
+}
+
+BLE::BLE(InstanceID_t instanceID) : transport()
+{
+    static BLEInstanceBase *transportInstances[NUM_INSTANCES];
+
+    if (instanceID < NUM_INSTANCES) {
+        if (!transportInstances[instanceID]) {
+            transportInstances[instanceID] = instanceConstructors[instanceID](); /* Call the stack's initializer for the transport object. */
+        }
+        transport = transportInstances[instanceID];
+    } else {
+        transport = NULL;
+    }
+}