B4J Question I cann't access spi

[jinyistudio]

Hi

Why it always give me number 18 when i running n1=wiringPiSPISetup(-1,-1) Or n1=wiringPiSPISetup(0,4000000) ?
When I debuging to jo.InitializeStatic("com.pi4j.wiringpi.Spi"), I find its all property is
null !
Do i need to install wiringPi into Raspberry PI ??

'Non-UI application (console / server application)
#Region Project Attributes
    #CommandLineArgs:
    #MergeLibraries: true
    '#AdditionalJar: pi4j-core.jar
#End Region

Sub Process_Globals

End Sub

Sub AppStart (Args() As String)
    Dim n1 As Int=wiringPiSPISetup(-1,-1)
    Log(n1)
    StartMessageLoop
End Sub

Sub WiringPiSPISetup(Channel As Int, Speed As Int) As Int
   Dim jo As JavaObject
   Return jo.InitializeStatic("com.pi4j.wiringpi.Spi").RunMethod("wiringPiSPISetup", Array As Object(Channel, Speed))
End Sub

Sub WiringPiSPIDataRW(Channel As Int, Data() As Byte, Len As Int) As Int
   Dim jo As JavaObject
   Return jo.InitializeStatic("com.pi4j.wiringpi.Spi").RunMethod("wiringPiSPIDataRW", Array As Object(Channel, Data, Len))
End Sub

 

[Erel]

I find its all property is
null !

This is fine. All the methods are static.

The value returned is the file descriptor. As long as it is not -1 then it it fine.

 

[jinyistudio]

1. as following, i pass -1 to channel,-1 to speed. it return 18 to me. Is it fine too ?
n1=wiringPiSPISetup(-1,-1)

This is fine. All the methods are static.
The value returned is the file descriptor. As long as it is not -1 then it it fine.

2. Do i need include library of pi4j.jar in the ide ?
3. Do i need install pi4j into raspberry pi ?

 

[Erel]

1. You should pass 0 or 1 as the channel. The speed should be between 500,000 to 32,000,000.
2. Yes.
3. No.