K4W v1 - Failed to set alternate interface #1 for K4W

[Alan Oursland]

I'm trying to get K4W v1 working on Ubuntu 14.

I have two questions:

1) I can see the K4W devices using "lsusb". I had to run "chmod 666 /dev/bus/usb/003/015" for each of the devices so that fcntl open would succeed. 

However, after I run my program, the device number for the audio increments. It only increments if I've changed chmod. 

If I haven't chmodded the audio device, I get the error "Failed to set the LED of the K4W device: -3". 

What is going on here? Can I fix it?

2) libusb_set_interface_alt_setting(dev, 0, 1) is failing with errors EINVAL which gets translated to LIBUSB_ERROR_NOT_FOUND. 

I don't know much about USB programming, but I'm guessing this is telling the Kinect to use a specific protocol and the Kinect is saying it doesn't know about it. 

Is this being caused by a missing firmware update? I see stuff about firmware updates happening automatically when you connect the device to a Windows machine. Is it possible to update the firmware from Ubuntu?

[Alan Oursland]

I unplugged the Kinect USB, chmodded the devices again, and it works.

I'd still like to understand what is happening.

The 51-rules file is what would let me avoid the chmod process, right?