Setup

Before developing the composite device, the user needs to:

  1. Decide how many classes are included in this composite device.

  2. Decide which types of classes are included in this composite device. For example, HID + AUDIO, HID + HID, and so on.

  3. Prepare the device descriptor depending on the use case. In particular, the IAD should be used for AUDIO/VIDEO class. For more information, see www.usb.org/developers/docs/whitepapers/iadclasscode_r10.pdf.

  4. Ensure that the functionality of the single function device code is valid.

Design steps

  1. A new composite device application should use the existing examples as a template.

  2. Prepare the descriptor-related data structure to ensure that the correct information about the customized composite device is related to the USB device stack. See USB composite device structures for additional information.

  3. Prepare the descriptors array and ensure that the descriptors are consistent with the descriptor-related data structure. See USB descriptor functions.

  4. Implement the specific descriptor-related callback function which the USB device stack calls to get the device descriptor. See USB descriptor functions.

Parent topic:Setup