B4J Question Again...B4j and I2C[SOLVED]

Return factory.InitializeStatic("com.pi4j.io.i2c.I2CFactory").RunMethodJO("getInstance", ArrayAsObject(BusNumber))

Dim bus As JavaObject = GetBus(0)
Dim device As JavaObject = GetDevice(bus, 0)
Write(device, 120) 'writes byte value 120

 Write (device,120)

Write (device,15,255)

Write2(device, Array As Byte(15, 255), 0, 2)

 Read2 (device,Array As Byte(0x12),0,1)

Sub Read2 (Device As JavaObject, Buffer() AsByte, Offset AsInt, Size AsInt) AsIntReturn Device.RunMethod("read", ArrayAsObject(Buffer, Offset, Size))End Sub

Dim buffer(1024) As Byte
Dim len As Int = Read2(device, buffer, 0, buffer.Length)

Sub AppStart (Args() As String)
Dim bus As JavaObject = GetBus(0)' Raspberry rev 1
Dim device As JavaObject = GetDevice(bus, 32)' all addressbits on the MCP23017 are high (0x20)
Dim i As Boolean
i= True
Dim buffer(20) As Byte ' see below
write2(device, Array As Byte(01,00),0,2) ' all bits on GPB (0x01) are output (0x00)
Do While i= True
Write2(device, Array As Byte(00, 8), 0, 2) ' GPIOA bit 3 set to INPUT. Try to set this command outside While loop.
' and debug buffer0 to buffer20. You see The state of these will shift.
Read2(device, buffer,0,20)' read first 20 bytes from several registers....setting offset to something else then 0 will result in java exception errors !
' in case of MCP23017 you need to ' read'  register 0x12 for the inputstate of GPA0-GPA7
' it was/is not possible to only read the state of 0x12. Therefore I load 20 registers.
If buffer(17) = -9 Then ' I need register 18 (0x12) to read state of GPA. During debug I see that i need register 17....
' maybe because of offset. Well...It works.
' have to do something about the -9 though. :-)
Log (" SET")
Write2(device, Array As Byte(0x15,0x01),0,2)' output GPB0 high
Else
Write2( device,Array As Byte (0x15,0x00),0,2)' output GPB- low
End If
Loop ' endless loop
End Sub