Fix #79 by fixing iBeacon format parsing (#81)

* TxPower should be signed value * Fix iBeacon parse function - reverse UUID info in iBeacon packets. We did this is BLEPeripheral but not in the parse function. - TxPower should be signed value, so change the data type in the interface. - fix endianess of Major and Minor values in the parse function. * Reverse UUID in iBeacon packet
MediaTek-Labs · Jan 9, 2018 · b2ef719 · b2ef719
1 parent 9f190fc
commit b2ef719
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Showing 4 changed files with 21 additions and 12 deletions.
diff --git a/...duino/hardware/arduino/mt7697/libraries/LBLE/examples/ScanPeripherals/ScanPeripherals.ino b/...duino/hardware/arduino/mt7697/libraries/LBLE/examples/ScanPeripherals/ScanPeripherals.ino
@@ -71,7 +71,7 @@ void printDeviceInfo(int i) {
   if (LBLECentral.isIBeacon(i)) {
     LBLEUuid uuid;
     uint16_t major = 0, minor = 0;
-    uint8_t txPower = 0;
+    int8_t txPower = 0;
     LBLECentral.getIBeaconInfo(i, uuid, major, minor, txPower);
 
     Serial.print(" ");

diff --git a/middleware/third_party/arduino/hardware/arduino/mt7697/libraries/LBLE/src/LBLECentral.cpp b/middleware/third_party/arduino/hardware/arduino/mt7697/libraries/LBLE/src/LBLECentral.cpp
@@ -158,7 +158,7 @@ LBLEUuid LBLEAdvertisements::getServiceUuid() const
     return LBLEUuid(uuid_data);
 }
 
-bool LBLEAdvertisements::getIBeaconInfo(LBLEUuid& uuid, uint16_t& major, uint16_t& minor, uint8_t& txPower) const
+bool LBLEAdvertisements::getIBeaconInfo(LBLEUuid& uuid, uint16_t& major, uint16_t& minor, int8_t& txPower) const
 {
     // for the iBeacon format, you may refer to
     // https://developer.mbed.org/blog/entry/BLE-Beacons-URIBeacon-AltBeacons-iBeacon/
@@ -188,15 +188,24 @@ bool LBLEAdvertisements::getIBeaconInfo(LBLEUuid& uuid, uint16_t& major, uint16_
         if(0x15 != beaconLength)
             break;
 
+        // note that iBeacon UUID are reversed w.r.t. our BT system
         bt_uuid_t tmpUuid;
-        memcpy(tmpUuid.uuid, iBeaconBuffer, sizeof(tmpUuid.uuid));
+        for(int i = 0; i < 16; ++i)
+        {
+            tmpUuid.uuid[i] = iBeaconBuffer[15-i];
+        }
         uuid = tmpUuid;
         iBeaconBuffer += 16;
+
 
-        major = *(unsigned short*)(iBeaconBuffer);
+        // note that the endian for major and minor are different.
+        major = *((uint16_t*)iBeaconBuffer);
+        major = (major >> 8) | ((major & 0xFF) << 8);
         iBeaconBuffer += 2;
 
-        minor = *(unsigned short*)(iBeaconBuffer);
+
+        minor = *((uint16_t*)iBeaconBuffer);
+        minor = (minor >> 8) | ((minor & 0xFF) << 8);      
         iBeaconBuffer += 2;
 
         txPower = *(int8_t*)iBeaconBuffer;
@@ -365,11 +374,11 @@ bool LBLECentralClass::isIBeacon(int index) const
 
     LBLEUuid uuid;
     uint16_t major, minor;
-    uint8_t txPower;
+    int8_t txPower;
     return parser.getIBeaconInfo(uuid, major, minor, txPower);
 }
 
-bool LBLECentralClass::getIBeaconInfo(int index, LBLEUuid& uuid, uint16_t& major, uint16_t& minor, uint8_t& txPower) const
+bool LBLECentralClass::getIBeaconInfo(int index, LBLEUuid& uuid, uint16_t& major, uint16_t& minor, int8_t& txPower) const
 {
     LBLEAdvertisements parser(m_peripherals_found[index]);
     return parser.getIBeaconInfo(uuid, major, minor, txPower);

diff --git a/middleware/third_party/arduino/hardware/arduino/mt7697/libraries/LBLE/src/LBLECentral.h b/middleware/third_party/arduino/hardware/arduino/mt7697/libraries/LBLE/src/LBLECentral.h
@@ -157,9 +157,9 @@ class LBLECentralClass : public LBLEEventObserver
 	/// \param uuid Output parameter of the iBeacon info - this UUID is defined by the iBeacon device.
 	/// \param major Output parameter, the major number in the iBeacon info.
 	/// \param minor Output parameter, the minor number in the iBeacon info.
-	/// \param minor Output parameter, the TX Power value in the iBeacon info.
+	/// \param txPower Output parameter, the signed TX Power value in the iBeacon info.
 	/// \returns true if the device has iBeacon info. false if the device is not an iBeacon device.
-	bool getIBeaconInfo(int index, LBLEUuid& uuid, uint16_t& major, uint16_t& minor, uint8_t& txPower)const;
+	bool getIBeaconInfo(int index, LBLEUuid& uuid, uint16_t& major, uint16_t& minor, int8_t& txPower)const;
 
 public:
 	// Event handlers and required data structure
@@ -203,7 +203,7 @@ class LBLEAdvertisements
 	uint8_t getAdvertisementFlag()const;
 
 	// returns false if this advertisment is not of iBeacon format.
-	bool getIBeaconInfo(LBLEUuid& uuid, uint16_t& major, uint16_t& minor, uint8_t& txPower) const;
+	bool getIBeaconInfo(LBLEUuid& uuid, uint16_t& major, uint16_t& minor, int8_t& txPower) const;
 
 	// Copy the "original" advertisement packet data
 	// bufLen should be the size of dstBuf.

diff --git a/middleware/third_party/arduino/hardware/arduino/mt7697/libraries/LBLE/src/LBLEPeriphral.cpp b/middleware/third_party/arduino/hardware/arduino/mt7697/libraries/LBLE/src/LBLEPeriphral.cpp
@@ -224,8 +224,8 @@ void LBLEAdvertisementData::configAsIBeacon(const LBLEUuid& uuid,
     }
 
     // 2 byte major number & 2 byte minor, note that the endian is different.
-    (*(uint16_t*)(item.adData + 20)) = (major >> 8) | (major << 8);
-    (*(uint16_t*)(item.adData + 22)) = (minor >> 8) | (minor << 8);
+    (*(uint16_t*)(item.adData + 20)) = (major >> 8) | ((major & 0xFF) << 8);
+    (*(uint16_t*)(item.adData + 22)) = (minor >> 8) | ((minor & 0xFF) << 8);
 
     // 1 byte TxPower (signed)
     item.adData[24] = (uint8_t)txPower;