BLE Scan Record Explanation
I'm trying to get UUID
, Major
, Minor IDs
from the BLE advertising, getting in shape byte[]
. I used the suggested code here , but I cannot understand the parser output. Here is the result I get for one of the BLE devices
Length: 2 Type : 1 Data : 6,
Length: 26 Type : -1 Data : 76 0 2 21 -9 -126 109 -90 79 -94 78 -104 -128 36 -68 91 113 -32 -119 62 12 -121 -79 52 -77,
Length: 8 Type : 9 Data : 75 111 110 116 97 107 116,
Length: 2 Type : 10 Data : -12,
Length: 10 Type : 22 Data : 13 -48 117 76 106 98 50 55 100
How do I figure out which field contains UUID
, major and minor ids ?, I read from the same post on stackoverflow, which 0x07
indicates UUID
, as I understand it, as the type 0x07
from the above data.
This is my first question, so I apologize for any mistakes in the way the question was asked.
Here's the code just in case:
public void printScanRecord (byte[] scanRecord) {
// Simply print all raw bytes
try {
String decodedRecord = new String(scanRecord,"UTF-8");
Log.d("DEBUG","decoded String : " + ByteArrayToString(scanRecord));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
// Parse data bytes into individual records
List<AdRecord> records = AdRecord.parseScanRecord(scanRecord);
// Print individual records
if (records.size() == 0) {
Log.i("DEBUG", "Scan Record Empty");
} else {
Log.i("DEBUG", "Scan Record: " + TextUtils.join(",", records));
}
}
public static String ByteArrayToString(byte[] ba)
{
StringBuilder hex = new StringBuilder(ba.length * 2);
for (byte b : ba)
hex.append(b + " ");
return hex.toString();
}
public static class AdRecord {
public AdRecord(int length, int type, byte[] data) {
String decodedRecord = "";
try {
decodedRecord = new String(data,"UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
Log.d("DEBUG", "Length: " + length + " Type : " + type + " Data : " + ByteArrayToString(data));
}
// ...
public static List<AdRecord> parseScanRecord(byte[] scanRecord) {
List<AdRecord> records = new ArrayList<AdRecord>();
int index = 0;
while (index < scanRecord.length) {
int length = scanRecord[index++];
//Done once we run out of records
if (length == 0) break;
int type = scanRecord[index];
//Done if our record isn't a valid type
if (type == 0) break;
byte[] data = Arrays.copyOfRange(scanRecord, index+1, index+length);
records.add(new AdRecord(length, type, data));
//Advance
index += length;
}
return records;
}
// ...
}
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I believe the type values ββare described in: Sharing Profile Web Page
I also made the parser code you could find at the bottom of mybletest / BLEBase.java .
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