PORTS Forum

Ports and Interfaces => USB => Topic started by: anthony.carr on October 04, 2013, 06:09:26 am

Title: Composite USB HID and audio device
Post by: anthony.carr on October 04, 2013, 06:09:26 am

Hi,

I have been developing USB HID products for several years and am familiar with the USB descriptor structure.
I have a requirement to develop a product that includes both an HID and audio device.
I have examples of the descriptors for both devices but I am not certain how to combine the different devices within the one descriptor.
Can anyone point me to or provide an example of how to combine the descriptors?

Thanks,

TC

Title: Re: Composite USB HID and audio device
Post by: Jan Axelson on October 04, 2013, 10:38:25 am

Get the audio function working first. Then add descriptors for the HID interface and increment bNumInterfaces in the configuration descriptor.

Also see:

www.atmel.com/images/doc6436.pdf

Title: Re: Composite USB HID and audio device
Post by: anthony.carr on October 10, 2013, 11:14:59 am

Thanks Jan.
I have combined the descriptors as you suggested and I now have my audio device and keyboard enumerating.
Many thanks for your advice. :)

Title: Re: Composite USB HID and audio device
Post by: anthony.carr on October 15, 2013, 06:10:18 am

Hi,

I have integrated the audio and HID devices into one as per Jan's suggestion and everything works on my windows XP system.
I then tested the unit out on Windows Vista and Windows 7 systems and whilst the device enumerates and I can see the devices are installed properly in device manager the audio does not produce any sound.
Device manager states that the audio device is working properly.
Does anyone have any suggestions as to why the audio device does not work on Vista and 7?

Thanks,

TJ

Title: Re: Composite USB HID and audio device
Post by: Jan Axelson on October 15, 2013, 10:16:25 am

These suggestions are pretty general, but:

A protocol analyzer will show if the data is transferring on the bus.

Try the Windows audio troubleshooter.