USB Vendor-specific request for Carplay

I'm tryng to develop a software that can connect an iPhone to a HMI Box in order to use CarPlay and test an app for CarPlay.

Since the starting point is to ask the device, i.e. the iPhone, if it supports CarPlay, I have to write a USB Vendor-Specific Request that the accessory send to know for this capability.

I would like to know what are the specific parameters to include in the control transfer request from accessory to device, especially: bRequest, wValue, wIndex. I've studied the whole Accessory Interface Specification Carplay Addendum, but i couldn't find anything.

Thanks in advance for your support.

This is essentially the same as making an accessory. We have a program called MFi for this. I would start there.

USB Vendor-specific request for Carplay
 
 
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