B4J Question Example of Len for SPI function in Raspberry Pi (B4J)?

[Kevin Sutanto]

Hello i'm new for using B4J, i want to using SPI bus in Rpi,

For this Function what should i fill in part of Len,

Sub WiringPiSPIDataRW(Channel As Int, Data() As Byte, Len As Int) As Int

Can anyone gift example for this function.
Thanks before

 

[Erel]

Here: https://www.b4x.com/android/forum/threads/iot-jpi4j-raspberry-pi-gpio-controller.37493/#post-230657