Thanks Erel
However I now have the reverse problem - see code
B4J Code
Private Sub DisplayTemperatures(Payload() As Byte)
'   Display Payload contents   
   Dim B As Byte
   For i = 0 To Payload.Length-1
       B = Payload(i)
       Log(B)
   Next
'   Test Display Double
   Dim D As Double = 20.925    ' Test
   Log(NumberFormat(D,0,2))    ' Test
'   Covert to Double and display
   Dim Buffer() As Double = bc.DoublesFromBytes(Payload)
   Dim E As Double = Buffer(0) ' Produces Error
   Log(NumberFormat(E,0,2)) 
End Sub
Log
  0
  -128
  -89
  65
  20.93
  Error occurred
Your help is appreciated! Donald