MicroBitEddystone.cpp

00001 /*
00002 The MIT License (MIT)
00003 
00004 Copyright (c) 2016 British Broadcasting Corporation.
00005 This software is provided by Lancaster University by arrangement with the BBC.
00006 
00007 Permission is hereby granted, free of charge, to any person obtaining a
00008 copy of this software and associated documentation files (the "Software"),
00009 to deal in the Software without restriction, including without limitation
00010 the rights to use, copy, modify, merge, publish, distribute, sublicense,
00011 and/or sell copies of the Software, and to permit persons to whom the
00012 Software is furnished to do so, subject to the following conditions:
00013 
00014 The above copyright notice and this permission notice shall be included in
00015 all copies or substantial portions of the Software.
00016 
00017 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00018 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00019 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
00020 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00021 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
00022 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
00023 DEALINGS IN THE SOFTWARE.
00024 */
00025 
00026 #include "MicroBitConfig.h"
00027 #include "MicroBitEddystone.h"
00028 
00029 MicroBitEddystone *MicroBitEddystone::_instance = NULL;
00030 
00031 /* The underlying Nordic libraries that support BLE do not compile cleanly with the stringent GCC settings we employ.
00032  * If we're compiling under GCC, then we suppress any warnings generated from this code (but not the rest of the DAL)
00033  * The ARM cc compiler is more tolerant. We don't test __GNUC__ here to detect GCC as ARMCC also typically sets this
00034  * as a compatability option, but does not support the options used...
00035  */
00036 #if !defined(__arm)
00037 #pragma GCC diagnostic ignored "-Wunused-function"
00038 #pragma GCC diagnostic push
00039 #pragma GCC diagnostic ignored "-Wunused-parameter"
00040 #endif
00041 
00042 /*
00043  * Return to our predefined compiler settings.
00044  */
00045 #if !defined(__arm)
00046 #pragma GCC diagnostic pop
00047 #endif
00048 
00049 const uint8_t EDDYSTONE_UUID[] = {0xAA, 0xFE};
00050 
00051 #if CONFIG_ENABLED(MICROBIT_BLE_EDDYSTONE_URL)
00052 const char *EDDYSTONE_URL_PREFIXES[] = {"http://www.", "https://www.", "http://", "https://"};
00053 const size_t EDDYSTONE_URL_PREFIXES_LENGTH = sizeof(EDDYSTONE_URL_PREFIXES) / sizeof(char *);
00054 const char *EDDYSTONE_URL_SUFFIXES[] = {".com/", ".org/", ".edu/", ".net/", ".info/", ".biz/", ".gov/", ".com", ".org", ".edu", ".net", ".info", ".biz", ".gov"};
00055 const size_t EDDYSTONE_URL_SUFFIXES_LENGTH = sizeof(EDDYSTONE_URL_SUFFIXES) / sizeof(char *);
00056 const int EDDYSTONE_URL_MAX_LENGTH = 18;
00057 const uint8_t EDDYSTONE_URL_FRAME_TYPE = 0x10;
00058 #endif
00059 
00060 #if CONFIG_ENABLED(MICROBIT_BLE_EDDYSTONE_UID)
00061 const int EDDYSTONE_UID_NAMESPACE_MAX_LENGTH = 10;
00062 const int EDDYSTONE_UID_INSTANCE_MAX_LENGTH = 6;
00063 const uint8_t EDDYSTONE_UID_FRAME_TYPE = 0x00;
00064 #endif
00065 
00066 /**
00067  * Constructor.
00068  *
00069  * Configure and manage the micro:bit's Bluetooth Low Energy (BLE) stack.
00070  *
00071  * @param _storage an instance of MicroBitStorage used to persist sys attribute information. (This is required for compatability with iOS).
00072  *
00073  * @note The BLE stack *cannot*  be brought up in a static context (the software simply hangs or corrupts itself).
00074  * Hence, the init() member function should be used to initialise the BLE stack.
00075  */
00076 MicroBitEddystone::MicroBitEddystone()
00077 {
00078 }
00079 
00080 MicroBitEddystone* MicroBitEddystone::getInstance()
00081 {
00082     if (_instance == 0)
00083         _instance = new MicroBitEddystone;
00084 
00085     return _instance;
00086 }
00087 
00088 #if CONFIG_ENABLED(MICROBIT_BLE_EDDYSTONE_URL)
00089 
00090 /**
00091   * Set the content of Eddystone URL frames
00092   *
00093   * @param url The url to broadcast
00094   *
00095   * @param calibratedPower the transmission range of the beacon (Defaults to: 0xF0 ~10m).
00096   *
00097   * @note The calibratedPower value ranges from -100 to +20 to a resolution of 1. The calibrated power should be binary encoded.
00098   * More information can be found at https://github.com/google/eddystone/tree/master/eddystone-uid#tx-power
00099   */
00100 int MicroBitEddystone::setURL(BLEDevice* ble, const char* url, int8_t calibratedPower)
00101 {
00102     int urlDataLength = 0;
00103     char urlData[EDDYSTONE_URL_MAX_LENGTH];
00104     memset(urlData, 0, EDDYSTONE_URL_MAX_LENGTH);
00105 
00106     if (url == NULL || strlen(url) == 0)
00107         return MICROBIT_INVALID_PARAMETER;
00108 
00109     // Prefix
00110     for (size_t i = 0; i < EDDYSTONE_URL_PREFIXES_LENGTH; i++)
00111     {
00112         size_t prefixLen = strlen(EDDYSTONE_URL_PREFIXES[i]);
00113         if (strncmp(url, EDDYSTONE_URL_PREFIXES[i], prefixLen) == 0)
00114         {
00115             urlData[urlDataLength++] = i;
00116             url += prefixLen;
00117             break;
00118         }
00119     }
00120 
00121     // Suffix
00122     while (*url && (urlDataLength < EDDYSTONE_URL_MAX_LENGTH))
00123     {
00124         size_t i;
00125         for (i = 0; i < EDDYSTONE_URL_SUFFIXES_LENGTH; i++)
00126         {
00127             size_t suffixLen = strlen(EDDYSTONE_URL_SUFFIXES[i]);
00128             if (strncmp(url, EDDYSTONE_URL_SUFFIXES[i], suffixLen) == 0)
00129             {
00130                 urlData[urlDataLength++] = i;
00131                 url += suffixLen;
00132                 break;
00133             }
00134         }
00135 
00136         // Catch the default case where the suffix doesn't match a preset ones
00137         if (i == EDDYSTONE_URL_SUFFIXES_LENGTH)
00138         {
00139             urlData[urlDataLength++] = *url;
00140             ++url;
00141         }
00142     }
00143 
00144     uint8_t rawFrame[EDDYSTONE_URL_MAX_LENGTH + 4];
00145     size_t index = 0;
00146     rawFrame[index++] = EDDYSTONE_UUID[0];
00147     rawFrame[index++] = EDDYSTONE_UUID[1];
00148     rawFrame[index++] = EDDYSTONE_URL_FRAME_TYPE;
00149     rawFrame[index++] = calibratedPower;
00150     memcpy(rawFrame + index, urlData, urlDataLength);
00151 
00152     ble->accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, EDDYSTONE_UUID, sizeof(EDDYSTONE_UUID));
00153     ble->accumulateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, rawFrame, index + urlDataLength);
00154 
00155     return MICROBIT_OK;
00156 }
00157 
00158 /**
00159   * Set the content of Eddystone URL frames, but accepts a ManagedString as a url.
00160   *
00161   * @param url The url to broadcast
00162   *
00163   * @param calibratedPower the transmission range of the beacon (Defaults to: 0xF0 ~10m).
00164   *
00165   * @note The calibratedPower value ranges from -100 to +20 to a resolution of 1. The calibrated power should be binary encoded.
00166   * More information can be found at https://github.com/google/eddystone/tree/master/eddystone-uid#tx-power
00167   */
00168 int MicroBitEddystone::setURL(BLEDevice* ble, ManagedString url, int8_t calibratedPower)
00169 {
00170     return setURL(ble, (char *)url.toCharArray(), calibratedPower);
00171 }
00172 #endif
00173 
00174 #if CONFIG_ENABLED(MICROBIT_BLE_EDDYSTONE_UID)
00175 
00176 /**
00177   * Set the content of Eddystone UID frames
00178   *
00179   * @param uid_namespace the uid namespace. Must 10 bytes long.
00180   *
00181   * @param uid_instance  the uid instance value. Must 6 bytes long.
00182   *
00183   * @param calibratedPower the transmission range of the beacon (Defaults to: 0xF0 ~10m).
00184   *
00185   * @note The calibratedPower value ranges from -100 to +20 to a resolution of 1. The calibrated power should be binary encoded.
00186   * More information can be found at https://github.com/google/eddystone/tree/master/eddystone-uid#tx-power
00187   */
00188 int MicroBitEddystone::setUID(BLEDevice* ble, const char* uid_namespace, const char* uid_instance, int8_t calibratedPower)
00189 {
00190     if (uid_namespace == NULL || uid_instance == NULL)
00191         return MICROBIT_INVALID_PARAMETER;
00192 
00193     char uidData[EDDYSTONE_UID_NAMESPACE_MAX_LENGTH + EDDYSTONE_UID_INSTANCE_MAX_LENGTH];
00194 
00195     // UID namespace
00196     memcpy(uidData, uid_namespace, EDDYSTONE_UID_NAMESPACE_MAX_LENGTH);
00197 
00198     // UID instance
00199     memcpy(uidData + EDDYSTONE_UID_NAMESPACE_MAX_LENGTH, uid_instance, EDDYSTONE_UID_INSTANCE_MAX_LENGTH);
00200 
00201     uint8_t rawFrame[EDDYSTONE_UID_NAMESPACE_MAX_LENGTH + EDDYSTONE_UID_INSTANCE_MAX_LENGTH + 4];
00202     size_t index = 0;
00203     rawFrame[index++] = EDDYSTONE_UUID[0];
00204     rawFrame[index++] = EDDYSTONE_UUID[1];
00205     rawFrame[index++] = EDDYSTONE_UID_FRAME_TYPE;
00206     rawFrame[index++] = calibratedPower;
00207     memcpy(rawFrame + index, uidData, EDDYSTONE_UID_NAMESPACE_MAX_LENGTH + EDDYSTONE_UID_INSTANCE_MAX_LENGTH);
00208 
00209     ble->accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, EDDYSTONE_UUID, sizeof(EDDYSTONE_UUID));
00210     ble->accumulateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, rawFrame, index + EDDYSTONE_UID_NAMESPACE_MAX_LENGTH + EDDYSTONE_UID_INSTANCE_MAX_LENGTH);
00211 
00212     return MICROBIT_OK;
00213 }
00214 
00215 #endif