Improve Eddystone support

Author: minoskt

SensingKit/SKEddystoneProximity.h

@@ -28,6 +28,6 @@
 
 @property (nonatomic, strong, readonly) NSString *namespaceFilter;
 
-- (id)initWithNamespace:(NSString *)namespaceFilter;
+- (id)initWithNamespaceFilter:(NSString *)namespaceFilter;
 
 @end

SensingKit/SKEddystoneProximity.m

@@ -30,21 +30,24 @@
 @interface SKEddystoneProximity () <ESSBeaconScannerDelegate>
 
 @property (strong, nonatomic) ESSBeaconScanner *beaconScanner;
+@property (strong, nonatomic, readonly) NSData *namespaceFilterData;
 
 @end
 
 @implementation SKEddystoneProximity
 
 - (id)init
 {
-    return [self initWithNamespace:nil];
+    return [self initWithNamespaceFilter:nil];
 }
 
-- (id)initWithNamespace:(NSString *)namespaceFilter;
+- (id)initWithNamespaceFilter:(NSString *)namespaceFilter;
 {
     if (self = [super init])
     {
-        _namespaceFilter = namespaceFilter;
+        // Save the hex filter in lowercase
+        _namespaceFilter = [namespaceFilter lowercaseString];
+        _namespaceFilterData = [SKEddystoneProximity dataFromHexString:_namespaceFilter];
 
         // init ESSBeaconScanner
         self.beaconScanner = [[ESSBeaconScanner alloc] init];
@@ -81,29 +84,30 @@ - (void)beaconFoundWithInfo:(ESSBeaconInfo *)beaconInfo
 {
     if (beaconInfo.beaconID.beaconType == kESSBeaconTypeEddystone) {
 
-        // 16 bytes long data. 10byte namespace + 6byte instance ID
+        // 16 bytes long data. 10byte namespaceId + 6byte instanceId
         NSData *beaconId = beaconInfo.beaconID.beaconID;
+        
+        // Separate the namespaceId (10 bytes)
         NSData *namespaceData = [beaconId subdataWithRange:NSMakeRange(0, 10)];
-
-        // Separate the namespace (10 bytes)
-        NSString *namespaceString = [self hexadecimalStringFromData:namespaceData];
 
-        if (!self.namespaceFilter || [self.namespaceFilter isEqualToString:namespaceString]) {
+        if (!self.namespaceFilter || [self.namespaceFilterData isEqualToData:namespaceData]) {
+            
+            // Convert NSData bytes into NSString
+            NSString *namespaceId = [SKEddystoneProximity hexStringFromData:namespaceData];
 
             // Separate the instanceId (6 bytes)
             NSData *instanceIdData = [beaconId subdataWithRange:NSMakeRange(10, 6)];
 
             // Convert NSData bytes into NSUInteger (quick and dirty way for now!)
-            NSString *instanceIdString = [self hexadecimalStringFromData:instanceIdData];
-            NSUInteger instanceId = instanceIdString.integerValue;
+            NSUInteger instanceId = [SKEddystoneProximity hexStringFromData:instanceIdData].integerValue;
 
             // Get all remaining properties
             NSInteger  rssi = beaconInfo.RSSI.integerValue;
             NSInteger  txPower = beaconInfo.txPower.integerValue;
 
             // Create and submit the data
             SKEddystoneProximityData *data = [[SKEddystoneProximityData alloc] initWithTimestamp:[NSDate date]
-                                                                                   withNamespace:namespaceString
+                                                                                 withNamespaceId:namespaceId
                                                                                   withInstanceId:instanceId
                                                                                         withRssi:rssi
                                                                                      withTxPower:txPower];
@@ -115,7 +119,7 @@ - (void)beaconFoundWithInfo:(ESSBeaconInfo *)beaconInfo
 
 // Serialize an NSData into a hexadeximal string
 // Thanks to http://stackoverflow.com/questions/1305225/best-way-to-serialize-a-nsdata-into-an-hexadeximal-string
-- (NSString *)hexadecimalStringFromData:(NSData *)data
++ (NSString *)hexStringFromData:(NSData *)data
 {
     const unsigned char *dataBuffer = (const unsigned char *)[data bytes];
 
@@ -131,4 +135,23 @@ - (NSString *)hexadecimalStringFromData:(NSData *)data
     return [NSString stringWithString:hexString];
 }
 
+// Convert a NSString hex into NSData
+// Thanks to ESSEddystone.m
++ (NSData *)dataFromHexString:(NSString *)hexString
+{
+    NSMutableData *data = [[NSMutableData alloc] init];
+    unsigned char whole_byte;
+    char byte_chars[3] = {'\0','\0','\0'};
+    
+    int i;
+    for (i = 0; i < [hexString length]/2; i++) {
+        byte_chars[0] = [hexString characterAtIndex:i * 2];
+        byte_chars[1] = [hexString characterAtIndex:i * 2 + 1];
+        whole_byte = strtol(byte_chars, NULL, 16);
+        [data appendBytes:&whole_byte length:1];
+    }
+    
+    return data;
+}
+
 @end

SensingKit/SKEddystoneProximityData.h

@@ -26,13 +26,13 @@
 
 @interface SKEddystoneProximityData : SKSensorData
 
-@property (nonatomic, strong, readonly) NSString *namespace;
+@property (nonatomic, strong, readonly) NSString *namespaceId;
 @property (nonatomic, readonly) NSUInteger instanceId;
 @property (nonatomic, readonly) NSInteger rssi;
 @property (nonatomic, readonly) NSInteger txPower;
 
 - (instancetype)initWithTimestamp:(NSDate *)timestamp
-                    withNamespace:(NSString *)namespace
+                  withNamespaceId:(NSString *)namespaceId
                    withInstanceId:(NSUInteger)instanceId
                          withRssi:(NSInteger)rssi
                       withTxPower:(NSInteger)txPower;

SensingKit/SKEddystoneProximityData.m

@@ -27,14 +27,14 @@
 @implementation SKEddystoneProximityData
 
 - (instancetype)initWithTimestamp:(NSDate *)timestamp
-                    withNamespace:(NSString *)namespace
+                  withNamespaceId:(NSString *)namespaceId
                    withInstanceId:(NSUInteger)instanceId
                          withRssi:(NSInteger)rssi
                       withTxPower:(NSInteger)txPower
 {
     if (self = [super initWithSensorModuleType:EddystoneProximity withTimestamp:timestamp])
     {
-        _namespace = namespace;
+        _namespaceId = [namespaceId lowercaseString];
         _instanceId = instanceId;
         _rssi = rssi;
         _txPower = txPower;
@@ -46,7 +46,7 @@ - (NSString *)csvString
 {
     return [NSString stringWithFormat:@"%f,%@,%lu,%ld,%ld",
             [self timestampEpoch],
-            _namespace,
+            _namespaceId,
             (unsigned long)_instanceId,
             (long)_rssi,
             (long)_txPower];
@@ -63,7 +63,7 @@ - (NSDictionary *)dictionaryData
                      @"timestampString": self.timestampString
                      },
              @"Eddystone": @{
-                     @"namespace": _namespace,
+                     @"namespace": _namespaceId,
                      @"instanceId": @(_instanceId),
                      @"rssi": @(_rssi),
                      @"txPower": @(_txPower)

SensingKit/SKSensorModuleManager.m

@@ -242,7 +242,8 @@ - (SKAbstractSensorModule *)createSensorModule:(SKSensorModuleType)moduleType
             break;
 
         case EddystoneProximity:
-            sensorModule = [[SKEddystoneProximity alloc] initWithNamespace:@"2f234454f4911ba9ffa6"];
+            // First 10 bytes of SHA1 'org.sensingkit.EddystoneIdentifier'
+            sensorModule = [[SKEddystoneProximity alloc] initWithNamespaceFilter:@"90643f1a5253bff747fa"];
             break;
 
             // Don't forget to break!