I receive data from BLE device which is in Hex Bytes (13 bytes of data).
When the received bytes are converted to hex string using ByteConverter: Dim notifyData As String = bc.HexFromBytes(data)
Displayed data look like this: 350100BF942C61B205CA18BA0B
But, when I display the value of each data byte as int using the following code:
The log output is:
The same happens for byte 4, 7, 9, 11
I can convert it to receive the correct value, by checking if it is negative value:
And then get: 256 + (- 65) = 191, which what 0xBF is.
The question is why? Why bytes values are treated as signed int?
When the received bytes are converted to hex string using ByteConverter: Dim notifyData As String = bc.HexFromBytes(data)
Displayed data look like this: 350100BF942C61B205CA18BA0B
But, when I display the value of each data byte as int using the following code:
B4X:
Dim notifyData As String = bc.HexFromBytes(data)
Log(notifyData.Length & " " & notifyData)
Dim j As Int = 0
Dim s As String
If data.Length = 13 Then
Dim i As Int
For i = 0 To data.Length-1
s = notifyData.SubString2(j, j+2)
j = j+2
Log(i & " " & data(i) & " " & s)
Next
End IfSo in the log you can see that for example for byte 3 - for hex value of 0xBF the byte value is displayed as -65
The same happens for byte 4, 7, 9, 11
I can convert it to receive the correct value, by checking if it is negative value:
B4X:
Dim k As Int
k = data(i)
If k < 0 Then
k = k + 256
End IfThe question is why? Why bytes values are treated as signed int?