Hi all, I'm trying to use JNA to talk over a USB device plugged into the computer. Using Java and a .dll that was provided to me. I am having trouble with the Write function:

C code:

typedef struct {
    unsigned int id;
    unsigned int timestamp;
    unsigned char flags;
    unsigned char len;
    unsigned char data[16];
} CANMsg;

CAN_STATUS canplus_Write(
        CANHANDLE handle, //long
    	CANMsg *msg
    );

Java Equivalent:

public class CANMsg extends Structure{
    public int id = 0;
    public int timestamp = 0;
    public byte flags = 0;
    public byte len = 8;
    public byte data[] = new byte[16];
}

int canplus_Write(NativeLong handle, CANMsg msg);

I have confirmed that I can open and close the device. The close requires the NativeLong handle, so i am assuming that the CANMsg msg is the issue here. I have also confirmed that the device works when tested with C only code.

I have read the the JNA documentation thoroughly... I think. Any pointers. Thanks all.