Diff: ble/services/EddystoneService.h

Revision:

771:26b809199308

Child:

782:5736312322d9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ble/services/EddystoneService.h	Fri Aug 07 15:55:21 2015 +0100
@@ -0,0 +1,540 @@
+/* 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.
+ */
+
+#ifndef SERVICES_EDDYSTONEBEACON_H_
+#define SERVICES_EDDYSTONEBEACON_H_
+
+#include "ble/BLE.h"
+#include "mbed.h"
+
+static const uint8_t BEACON_EDDYSTONE[] = {0xAA, 0xFE};
+
+#if 0
+#define INFO(MSG, ...) printf("[EddyStone: INFO]" MSG " \t[%s,%d]\r\n", ##__VA_ARGS__, __FILE__, __LINE__);
+#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
+#define INFO(MSG, ...)
+#define DBG(MSG, ...)
+#define WARN(MSG, ...)
+#define ERR(MSG, ...)
+#endif // if 0
+
+/**
+* @class Eddystone
+* @brief Eddystone Configuration Service. Can be used to set URL, adjust power levels, and set flags.
+* See https://github.com/google/eddystone
+*
+*/
+class EddystoneService
+{
+public:
+    static const unsigned ADVERTISING_INTERVAL_MSEC = 1000; // Advertising interval for config service.
+    static const size_t   SERVICE_DATA_MAX          = 31;   // Maximum size of service data in ADV packets
+
+    static const size_t URI_DATA_MAX = 18;
+    typedef uint8_t UriData_t[URI_DATA_MAX];
+
+    // UID Frame Type subfields
+    static const size_t UID_NAMESPACEID_SIZE = 10;
+    static const size_t UID_INSTANCEID_SIZE  = 6;
+    typedef uint8_t UIDNamespaceID_t[UID_NAMESPACEID_SIZE];
+    typedef uint8_t UIDInstanceID_t[UID_INSTANCEID_SIZE];
+
+    // Eddystone Frame Type ID
+    enum {
+        FRAME_TYPE_UID = 0x00,
+        FRAME_TYPE_URL = 0x10,
+        FRAME_TYPE_TLM = 0x20,
+        NUM_FRAMETYPES = 3
+    };
+
+    static const uint8_t FRAME_SIZE_UID = 20; // includes RFU bytes
+    static const uint8_t FRAME_SIZE_TLM = 14; // TLM frame is a constant 14Bytes
+
+public:
+    /**
+     * Constructor: sets up the parameters used by the Eddystone beacon.
+     * This function should be used in lieu of the config service.
+     *
+     * @param bleIn
+     *            ble object for the underlying controller.
+     * @oaram interval
+     *            This is is how often broadcasts are made (in units of milliseconds).
+     * @param txPowerLevel
+     *            The broadcasting power level (in dbM).
+     * @param UIDNamespaceID
+     *            10-Byte Namespace UUID.
+     * @param UIDInstanceID
+     *            6-Byte Instance UUID.
+     * @param url
+     *            Shortened URL to broadcast (pass in as a string).
+     * @param tlmVersion
+     *            version of telemetry data field to use (default to 0x00).
+     */
+    EddystoneService(BLEDevice     &bleIn,
+                     uint16_t       interval       = 100,
+                     uint8_t        txPowerLevel   = 0,
+                     const uint8_t *UIDNamespaceID = NULL,
+                     const uint8_t *UIDInstanceID  = NULL,
+                     const char    *url            = NULL,
+                     uint8_t        tlmVersion     = 0) :
+        ble(bleIn),
+        uidIsSet(false),
+        urlIsSet(false),
+        frameIndex(0),
+        uidRFU(0),
+        switchFlag(true),
+        TlmPduCount(0),
+        TlmTimeSinceBoot(0)
+    {
+        // Check optional frames, set their 'isSet' flags appropriately
+        if ((UIDNamespaceID != NULL) & (UIDInstanceID != NULL)) {
+            setUIDFrameData(txPowerLevel, UIDNamespaceID, UIDInstanceID);
+            uidIsSet = true;
+        } else if (url != NULL) {
+            setURLFrameData(txPowerLevel, url);
+            urlIsSet = true;
+        } else {
+            // Default TLM frame to version 0x00, start all values at zero to be spec compliant.
+            setTLMFrameData(tlmVersion, 0x00, 0x00);
+        }
+
+        ble.gap().setTxPower(txPowerLevel);
+        ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_NON_CONNECTABLE_UNDIRECTED);
+        ble.gap().setAdvertisingInterval(interval);
+
+        ble.gap().clearAdvertisingPayload();
+        ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
+        ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, BEACON_EDDYSTONE, sizeof(BEACON_EDDYSTONE));
+
+        // Construct TLM Frame in initial advertising.
+        uint8_t  serviceData[SERVICE_DATA_MAX];
+        unsigned serviceDataLen = 0;
+        serviceData[serviceDataLen++] = BEACON_EDDYSTONE[0];
+        serviceData[serviceDataLen++] = BEACON_EDDYSTONE[1];
+        serviceDataLen               += constructTLMFrame(serviceData + serviceDataLen, SERVICE_DATA_MAX);
+        ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, serviceData, serviceDataLen);
+
+        ble.gap().startAdvertising();
+        ble.gap().onRadioNotification(this, &EddystoneService::radioNotificationCallback);
+
+        timeSinceBootTick.attach(this, &EddystoneService::tsbCallback, 0.1); // increment the TimeSinceBoot ticker every 0.1s
+    }
+
+    /*
+     *  Update the TLM frame battery voltage value
+     *  @param[in] voltagemv Voltage to update the TLM field battery voltage with (in mV)
+     *  @return nothing
+     */
+    void updateTlmBatteryVoltage(uint16_t voltagemv) {
+        TlmBatteryVoltage = voltagemv;
+    }
+
+    /*
+     *  Update the TLM frame beacon temperature
+     *  @param[in] temp Temperature of beacon (in 8.8fpn)
+     *  @return nothing
+     */
+    void updateTlmBeaconTemp(uint16_t temp) {
+        TlmBeaconTemp = temp;
+    }
+
+    /*
+     *  Update the TLM frame PDU Count field
+     *  @param[in] pduCount Number of Advertising frames sent since power-up
+     */
+    void updateTlmPduCount(uint32_t pduCount) {
+        TlmPduCount = pduCount;
+    }
+
+    /*
+     *  Update the TLM frame Time since boot in 0.1s increments
+     *  @param[in] timeSinceBoot Time since boot in 0.1s increments
+     */
+    void updateTlmTimeSinceBoot(uint32_t timeSinceBoot) {
+        TlmTimeSinceBoot = timeSinceBoot;
+    }
+
+protected:
+    /*
+     *  callback function, called every 0.1s, increments the TimeSinceBoot field in the TLM frame
+     */
+    virtual void tsbCallback(void) {
+        TlmTimeSinceBoot++;
+    }
+
+private:
+    /*
+     *  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, const UIDNamespaceID_t namespaceID, const UIDInstanceID_t instanceID, uint16_t RFU = 0x0000) {
+        if (power > 20) {
+            power = 20;
+        }
+        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 doesn't really matter yet.
+    }
+
+    /**
+     *  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 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) {
+        if (maxSize < FRAME_SIZE_UID) {
+            return -1;
+        }
+
+        unsigned index = 0;
+        data[index++] = FRAME_TYPE_UID; // 1B  Type
+
+        if (defaultUidPower > 20) { // enforce range of valid values.
+            defaultUidPower = 20;
+        }
+        if (defaultUidPower < -100) {
+            defaultUidPower = -100;
+        }
+        data[index++] = defaultUidPower; // 1B  Power @ 0meter
+
+        for (size_t x = 0; x < UID_NAMESPACEID_SIZE; x++) { // 10B Namespce ID
+            data[index++] = defaultUidNamespaceID[x];
+        }
+
+        for (size_t x = 0; x< UID_INSTANCEID_SIZE; x++) { // 6B  Instance ID
+            data[index++] = defaultUidInstanceID[x];
+        }
+
+        if (uidRFU) { // 2B RFU, include if non-zero, otherwise ignore
+            data[index++] = (uint8_t)(uidRFU >> 0);
+            data[index++] = (uint8_t)(uidRFU >> 8);
+        }
+
+        return index;
+    }
+
+    /*
+     * Update advertising data
+     * @return true on success, false on failure
+     */
+    bool updateAdvPacket(const uint8_t serviceData[], unsigned serviceDataLen) {
+        return (ble.gap().updateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, serviceData, serviceDataLen) == BLE_ERROR_NONE);
+    }
+
+    /*
+     *  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
+        }
+        return false;
+    }
+
+    /**
+     *  Construct URL 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 empty space is available to write to.
+     *
+     *  @return number of bytes used. negative number indicates error message.
+     */
+    int constructURLFrame(uint8_t *data, uint8_t maxSize) {
+        if (maxSize < (1 + 1 + defaultUriDataLength)) {
+            return -1;
+        }
+
+        unsigned index = 0;
+        data[index++] = FRAME_TYPE_URL;                     // 1B  Type
+        data[index++] = defaultUrlPower;                    // 1B  TX Power
+        for (size_t x = 0; x < defaultUriDataLength; x++) { // 18B of URL Prefix + encoded URL
+            data[index++] = defaultUriData[x];
+        }
+
+        return index;
+    }
+
+    /*
+     *  Set Eddystone TLM Frame information.
+     *  @param[in] Version    of the TLM beacon data format
+     *  @param batteryVoltage in millivolts
+     *  @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;
+        TlmBatteryVoltage = batteryVoltage;
+        TlmBeaconTemp     = beaconTemp;
+        TlmPduCount       = pduCount; // reset
+        TlmTimeSinceBoot  = timeSinceBoot; // reset
+    }
+
+    /*
+     *  Construct TLM 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 empty space is available to write to.
+     *
+     *  @return number of bytes used. negative number indicates error message.
+     */
+    int constructTLMFrame(uint8_t *data, uint8_t maxSize) {
+        if (maxSize < FRAME_SIZE_TLM) {
+            return -1;
+        }
+
+        unsigned 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]
+
+        return index;
+    }
+
+    /*
+     *   State machine for switching out frames.
+     *   This function is called by the radioNotificationCallback when a frame needs to get swapped out.
+     *   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];
+
+        //hard code in the Eddystone UUID
+        unsigned serviceDataLen = 0;
+        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:
+                // 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++;
+                break;
+        }
+    }
+
+    /*
+     *  Callback from onRadioNotification(), used to update the PDUCounter and process next state.
+     */
+    void radioNotificationCallback(bool radioActive) {
+        static const unsigned EDDYSTONE_SWAPFRAME_DELAYMS = 1;
+
+        // Update PDUCount
+        TlmPduCount++;
+        frameIndex = frameIndex % NUM_FRAMETYPES;
+
+        if (!radioActive) { // false just after a frame is sent
+            // 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;
+            }
+        }
+    }
+
+private:
+    BLEDevice         &ble;
+    Ticker            timeSinceBootTick;
+    Timeout           switchFrame;
+    // Default value that is restored on reset
+    size_t            defaultUriDataLength;
+    UriData_t         defaultUriData;
+    UIDNamespaceID_t  defaultUidNamespaceID;
+    UIDInstanceID_t   defaultUidInstanceID;
+    int8_t            defaultUidPower;
+    int8_t            defaultUrlPower;
+    unsigned          frameIndex;
+    uint16_t          uidRFU;
+    bool              uidIsSet;
+    bool              urlIsSet;
+    bool              switchFlag;
+
+    // Private Variables for Telemetry Data
+    uint8_t           TlmVersion;
+    volatile uint16_t TlmBatteryVoltage;
+    volatile uint16_t TlmBeaconTemp;
+    volatile uint32_t TlmPduCount;
+    volatile uint32_t TlmTimeSinceBoot;
+
+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[] = {
+            "http://www.",
+            "https://www.",
+            "http://",
+            "https://",
+        };
+        const size_t NUM_PREFIXES = sizeof(prefixes) / sizeof(char *);
+        const char *suffixes[] = {
+            ".com/",
+            ".org/",
+            ".edu/",
+            ".net/",
+            ".info/",
+            ".biz/",
+            ".gov/",
+            ".com",
+            ".org",
+            ".edu",
+            ".net",
+            ".info",
+            ".biz",
+            ".gov"
+        };
+        const size_t NUM_SUFFIXES = sizeof(suffixes) / sizeof(char *);
+
+        sizeofURIDataOut = 0;
+        memset(uriDataOut, 0, sizeof(UriData_t));
+
+        if ((uriDataIn == NULL) || (strlen(uriDataIn) == 0)) {
+            return;
+        }
+
+        /*
+         * handle prefix
+         */
+        for (unsigned i = 0; i < NUM_PREFIXES; i++) {
+            size_t prefixLen = strlen(prefixes[i]);
+            if (strncmp(uriDataIn, prefixes[i], prefixLen) == 0) {
+                uriDataOut[sizeofURIDataOut++]  = i;
+                uriDataIn                      += prefixLen;
+                break;
+            }
+        }
+
+        /*
+         * handle suffixes
+         */
+        while (*uriDataIn && (sizeofURIDataOut < URI_DATA_MAX)) {
+            /* check for suffix match */
+            unsigned i;
+            for (i = 0; i < NUM_SUFFIXES; i++) {
+                size_t suffixLen = strlen(suffixes[i]);
+                if (strncmp(uriDataIn, suffixes[i], suffixLen) == 0) {
+                    uriDataOut[sizeofURIDataOut++]  = i;
+                    uriDataIn                      += suffixLen;
+                    break; /* from the for loop for checking against suffixes */
+                }
+            }
+            /* This is the default case where we've got an ordinary character which doesn't match a suffix. */
+            if (i == NUM_SUFFIXES) {
+                uriDataOut[sizeofURIDataOut++] = *uriDataIn;
+                ++uriDataIn;
+            }
+        }
+    }
+};
+
+#endif  // SERVICES_EDDYSTONEBEACON_H_
\ No newline at end of file