/**
* findDevice - finds and returns the device that is lasted connected, and matches both the vendor
* and product id (please use enums provided in MindStormDevice for parameters)
*
* @param vendorId - vendor id for USB device
* @param productId - product id for USB device
* @return
*/
private static Device findDevice(short vendorId, short productId) {
// Read the USB device list
DeviceList list = new DeviceList();
Context context = new Context();
LibUsb.init(context);
int result = LibUsb.getDeviceList(context, list);
if (result < 0) throw new LibUsbException("Unable to get device list", result);
try {
// Iterate over all devices and scan for the right one
for (Device device : list) {
DeviceDescriptor descriptor = new DeviceDescriptor();
result = LibUsb.getDeviceDescriptor(device, descriptor);
if (result != LibUsb.SUCCESS)
throw new LibUsbException("Unable to read device descriptor", result);
if (descriptor.idVendor() == vendorId && descriptor.idProduct() == productId) return device;
}
} finally {
// Ensure the allocated device list is freed
LibUsb.freeDeviceList(list, true);
}
// Device not found
return null;
}
