The usbdescriptors_ files contain raw USB descriptors from the Google
USB-C to 3.5mm adapter, with different loads connected to the 3.5mm
jack.
usbdescriptors_nothing.bin:
- The descriptors when the jack is disconnected.
usbdescriptors_headphones.bin:
- The descriptors when the jack is connected to 32-ohm headphones,
no microphone.
The relevant output terminal is:
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 15
wTerminalType 0x0302 Headphones
usbdescriptors_lineout.bin:
- The descriptors when the jack is connected to a PC line-in jack.
The relevant output terminal is:
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 15
wTerminalType 0x0603 Line Connector
usbdescriptors_headset.bin:
- The descriptors when a headset with microphone and low-impedance
headphones are connected.
The relevant input terminal is:
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0201 Microphone
The relevant output terminal is:
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 15
wTerminalType 0x0302 Headphones