usbserial
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Published
20 hours ago •
altera2015
altera2015
Feature: Enumerate interfaces
The API allows for connecting to a device by index, but does not present a way to see what all of the interfaces are.
Nordic Semiconductor recently started shipping all of their development kits with an nRF5340 chip as the debug chip, even for older DK's like the nRF52832 and nRF52840. This presents TWO serial ports; the first one is the debug interface, and the second is the UART passthrough to the MCU.
It would be nice to have some more details about these interfaces programmatically. Some other libraries which are focused on more generic USB functionality provide more granular API to select the communication path which is available from Android:
- UsbDevice.getConfiguration() to access one or more
- UsbConfiguration.getInterface() to access one or more
- UsbInterface.getEndpoint() to access one or more
- UsbEndpoint
Also here is the USB enumeration of an nRF52840 DK, for reference:
Information for device J-Link (VID=0x1366 PID=0x1051):
------------------------------
Connection Information:
------------------------------
Device current bus speed: FullSpeed
Device supports USB 1.1 specification
Device supports USB 2.0 specification
Device address: 0x000C
Current configuration value: 0x01
Number of open pipes: 10
------------------------------
Device Descriptor:
------------------------------
0x12 bLength
0x01 bDescriptorType
0x0200 bcdUSB
0xEF bDeviceClass (Miscellaneous device)
0x02 bDeviceSubClass
0x01 bDeviceProtocol
0x40 bMaxPacketSize0 (64 bytes)
0x1366 idVendor
0x1051 idProduct
0x0100 bcdDevice
0x01 iManufacturer "SEGGER"
0x02 iProduct "J-Link"
0x03 iSerialNumber "001050221072"
0x01 bNumConfigurations
-------------------------
Configuration Descriptor:
-------------------------
0x09 bLength
0x02 bDescriptorType
0x00BB wTotalLength (187 bytes)
0x06 bNumInterfaces
0x01 bConfigurationValue
0x04 iConfiguration "Configuration"
0x80 bmAttributes (Bus-powered Device)
0x32 bMaxPower (100 mA)
Interface Association Descriptor:
------------------------------
0x08 bLength
0x0B bDescriptorType
0x00 bFirstInterface
0x02 bInterfaceCount
0x02 bFunctionClass (Communication Device Class)
0x02 bFunctionSubClass (Abstract Control Model - ACM)
0x00 bFunctionProtocol
0x05 iFunction "CDC"
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x00 bInterfaceNumber
0x00 bAlternateSetting
0x01 bNumEndPoints
0x02 bInterfaceClass (Communication Device Class)
0x02 bInterfaceSubClass (Abstract Control Model - ACM)
0x01 bInterfaceProtocol (ITU-T V.250)
0x05 iInterface "CDC"
CDC Header Functional Descriptor:
------------------------------
0x05 bFunctionalLength
0x24 bDescriptorType
0x00 bDescriptorSubtype
0x0110 bcdCDC
CDC Call Management Functional Descriptor:
------------------------------
0x05 bFunctionalLength
0x24 bDescriptorType
0x01 bDescriptorSubtype
0x03 bmCapabilities
0x01 bDataInterface
CDC Abstract Control Management Functional Descriptor:
------------------------------
0x04 bFunctionalLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x06 bmCapabilities
CDC Union Functional Descriptor:
------------------------------
0x05 bFunctionalLength
0x24 bDescriptorType
0x06 bDescriptorSubtype
0x00 bControlInterface
0x01 bSubordinateInterface(0)
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x82 bEndpointAddress (IN endpoint 2)
0x03 bmAttributes (Transfer: Interrupt / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (1 x 64 bytes)
0x01 bInterval (1 frames)
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x01 bInterfaceNumber
0x00 bAlternateSetting
0x02 bNumEndPoints
0x0A bInterfaceClass (CDC Data)
0x00 bInterfaceSubClass
0x00 bInterfaceProtocol
0x06 iInterface "CDC DATA interface"
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x81 bEndpointAddress (IN endpoint 1)
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (64 bytes)
0x01 bInterval
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x01 bEndpointAddress (OUT endpoint 1)
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (64 bytes)
0x01 bInterval
Interface Association Descriptor:
------------------------------
0x08 bLength
0x0B bDescriptorType
0x02 bFirstInterface
0x02 bInterfaceCount
0x02 bFunctionClass (Communication Device Class)
0x02 bFunctionSubClass (Abstract Control Model - ACM)
0x00 bFunctionProtocol
0x07 iFunction "CDC"
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x02 bInterfaceNumber
0x00 bAlternateSetting
0x01 bNumEndPoints
0x02 bInterfaceClass (Communication Device Class)
0x02 bInterfaceSubClass (Abstract Control Model - ACM)
0x01 bInterfaceProtocol (ITU-T V.250)
0x07 iInterface "CDC"
CDC Header Functional Descriptor:
------------------------------
0x05 bFunctionalLength
0x24 bDescriptorType
0x00 bDescriptorSubtype
0x0110 bcdCDC
CDC Call Management Functional Descriptor:
------------------------------
0x05 bFunctionalLength
0x24 bDescriptorType
0x01 bDescriptorSubtype
0x03 bmCapabilities
0x03 bDataInterface
CDC Abstract Control Management Functional Descriptor:
------------------------------
0x04 bFunctionalLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x06 bmCapabilities
CDC Union Functional Descriptor:
------------------------------
0x05 bFunctionalLength
0x24 bDescriptorType
0x06 bDescriptorSubtype
0x02 bControlInterface
0x03 bSubordinateInterface(0)
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x84 bEndpointAddress (IN endpoint 4)
0x03 bmAttributes (Transfer: Interrupt / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (1 x 64 bytes)
0x01 bInterval (1 frames)
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x03 bInterfaceNumber
0x00 bAlternateSetting
0x02 bNumEndPoints
0x0A bInterfaceClass (CDC Data)
0x00 bInterfaceSubClass
0x00 bInterfaceProtocol
0x08 iInterface "CDC DATA interface"
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x83 bEndpointAddress (IN endpoint 3)
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (64 bytes)
0x01 bInterval
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x02 bEndpointAddress (OUT endpoint 2)
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (64 bytes)
0x01 bInterval
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x04 bInterfaceNumber
0x00 bAlternateSetting
0x02 bNumEndPoints
0xFF bInterfaceClass (Vendor specific)
0xFF bInterfaceSubClass
0xFF bInterfaceProtocol
0x09 iInterface "BULK interface"
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x85 bEndpointAddress (IN endpoint 5)
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (64 bytes)
0x01 bInterval
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x03 bEndpointAddress (OUT endpoint 3)
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (64 bytes)
0x01 bInterval
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x05 bInterfaceNumber
0x00 bAlternateSetting
0x02 bNumEndPoints
0x08 bInterfaceClass (Mass Storage Device Class)
0x06 bInterfaceSubClass (Transparent SCSI subclass)
0x50 bInterfaceProtocol (Bulk only transport)
0x0A iInterface "MSD interface"
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x86 bEndpointAddress (IN endpoint 6)
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (64 bytes)
0x01 bInterval
Endpoint Descriptor:
------------------------------
0x07 bLength
0x05 bDescriptorType
0x04 bEndpointAddress (OUT endpoint 4)
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)
0x0040 wMaxPacketSize (64 bytes)
0x01 bInterval
Microsoft OS Descriptor is not available. Error code: 0x0000001F
--------------------------------
String Descriptor Table
--------------------------------
Index LANGID String
0x00 0x0000 0x0409
0x01 0x0409 "SEGGER"
0x02 0x0409 "J-Link"
0x03 0x0409 "001050221072"
0x04 0x0409 "Configuration"
0x05 0x0409 "CDC"
0x06 0x0409 "CDC DATA interface"
0x07 0x0409 "CDC"
0x08 0x0409 "CDC DATA interface"
0x09 0x0409 "BULK interface"
0x0A 0x0409 "MSD interface"
------------------------------
Connection path for device:
USB xHCI Compliant Host Controller
Root Hub
Generic USB Hub
Generic USB Hub
J-Link (VID=0x1366 PID=0x1051) Port: 1
Running on: Windows 10 or greater (Build Version 22621)
Brought to you by TDD v2.17.0, Feb 23 2021, 14:04:02
If the UsbSerial Java library supports this it would be doable to add it. However I do not have this hardware and won't be able to implement this. Also I need to make sure to not break backward compat.
The connection API already supports taking an index, so if there was a separate API to list out what those indexable items are then the existing one wouldn't have to break. But as a new API it would have to have support in all of the various plugins in such a way that the list it returns correlates to the index number passed in.
As for testing, many USB devices have multiple interfaces (including other phones); but at least you should be able to return a list of at least one entry in all cases. I could try to help with testing on Android at least.