I am trying to stream data from a USB sensor-type device. I have tried the following code:
import usb.core
device = usb.find(idVendor=0x1234, idProduct=0x4321)
print(device.read(0x81, 7))
The output I get is:
array('B', [1, 96])
I'm really unsure how to use this and get meaningful sensor data. Could anyone point me in the right direction?
For info, here's the output I get when I run print(device):
DEVICE ID 1234:4321 on Bus 001 Address 013 =================
bLength : 0x12 (18 bytes)
bDescriptorType : 0x1 Device
bcdUSB : 0x200 USB 2.0
bDeviceClass : 0x0 Specified at interface
bDeviceSubClass : 0x0
bDeviceProtocol : 0x0
bMaxPacketSize0 : 0x8 (8 bytes)
idVendor : 0x0403
idProduct : 0xc2b0
bcdDevice : 0x1000 Device 16.0
iManufacturer : 0x1 XXXXXXXXXXXX
iProduct : 0x2 XXXX
iSerialNumber : 0x0
bNumConfigurations : 0x1
CONFIGURATION 1: 500 mA ==================================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x2 Configuration
wTotalLength : 0x20 (32 bytes)
bNumInterfaces : 0x1
bConfigurationValue : 0x1
iConfiguration : 0x0
bmAttributes : 0x80 Bus Powered
bMaxPower : 0xfa (500 mA)
INTERFACE 0: Vendor Specific ===========================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x4 Interface
bInterfaceNumber : 0x0
bAlternateSetting : 0x0
bNumEndpoints : 0x2
bInterfaceClass : 0xff Vendor Specific
bInterfaceSubClass : 0xff
bInterfaceProtocol : 0xff
iInterface : 0x2 XXXX
ENDPOINT 0x81: Bulk IN ===============================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x81 IN
bmAttributes : 0x2 Bulk
wMaxPacketSize : 0x40 (64 bytes)
bInterval : 0x0
ENDPOINT 0x2: Bulk OUT ===============================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x2 OUT
bmAttributes : 0x2 Bulk
wMaxPacketSize : 0x40 (64 bytes)
bInterval : 0x0
Related
I'm currently working on USB headset using stm32 microcontroller. I used example code from X-CUBE-USB-AUDIO package to stream audio to\from PC. Everything seems to work fine. Now I want to modify the code to allow USB device to notify the host of volume/mute changes. According to USB audio specification 1.0 p.30, an optional Status Interrupt Endpoint can be used for this purpose. So I modified device descriptor to include that optional endpoint. Here is the original descriptor:
Information for device STM32 AUDIO Streaming in FS Mode (VID=0x0483 PID=0x5730):
Connection Information:
------------------------------
Device current bus speed: FullSpeed
Device supports USB 1.1 specification
Device supports USB 2.0 specification
Device address: 0x004B
Current configuration value: 0x01
Number of open pipes: 0
Device Descriptor:
------------------------------
0x12 bLength
0x01 bDescriptorType
0x0200 bcdUSB
0x00 bDeviceClass
0x00 bDeviceSubClass
0x00 bDeviceProtocol
0x40 bMaxPacketSize0 (64 bytes)
0x0483 idVendor
0x5730 idProduct
0x0200 bcdDevice
0x01 iManufacturer "STMicroelectronics"
0x02 iProduct "STM32 AUDIO Streaming in FS Mode"
0x03 iSerialNumber "368932633438"
0x01 bNumConfigurations
Configuration Descriptor:
------------------------------
0x09 bLength
0x02 bDescriptorType
0x00CB wTotalLength (203 bytes)
0x03 bNumInterfaces
0x01 bConfigurationValue
0x00 iConfiguration
0xC0 bmAttributes (Self-powered Device)
0x32 bMaxPower (100 mA)
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x00 bInterfaceNumber
0x00 bAlternateSetting
0x00 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x01 bInterfaceSubClass (Audio Control Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
AC Interface Header Descriptor:
------------------------------
0x0A bLength
0x24 bDescriptorType
0x01 bDescriptorSubtype
0x0100 bcdADC
0x0048 wTotalLength (72 bytes)
0x02 bInCollection
0x01 baInterfaceNr(1)
0x02 baInterfaceNr(2)
AC Input Terminal Descriptor:
------------------------------
0x0C bLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x12 bTerminalID
0x0101 wTerminalType (USB Streaming)
0x00 bAssocTerminal
0x02 bNrChannels (2 channels)
0x0003 wChannelConfig
0x00 iChannelNames
0x00 iTerminal
AC Feature Unit Descriptor:
------------------------------
0x0A bLength
0x24 bDescriptorType
0x06 bDescriptorSubtype
0x16 bUnitID
0x12 bSourceID
0x01 bControlSize
bmaControls:
0x03 Channel(0) - Mute / Volume
0x00 Channel(1)
0x00 Channel(2)
0x00 iFeature
AC Output Terminal Descriptor:
------------------------------
0x09 bLength
0x24 bDescriptorType
0x03 bDescriptorSubtype
0x14 bTerminalID
0x0301 wTerminalType (Speaker)
0x00 bAssocTerminal
0x16 bSourceID
0x00 iTerminal
AC Input Terminal Descriptor:
------------------------------
0x0C bLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x11 bTerminalID
0x0201 wTerminalType (Microphone)
0x00 bAssocTerminal
0x02 bNrChannels (2 channels)
0x0003 wChannelConfig
0x00 iChannelNames
0x00 iTerminal
AC Feature Unit Descriptor:
------------------------------
0x0A bLength
0x24 bDescriptorType
0x06 bDescriptorSubtype
0x15 bUnitID
0x11 bSourceID
0x01 bControlSize
bmaControls:
0x03 Channel(0) - Mute / Volume
0x00 Channel(1)
0x00 Channel(2)
0x00 iFeature
AC Output Terminal Descriptor:
------------------------------
0x09 bLength
0x24 bDescriptorType
0x03 bDescriptorSubtype
0x13 bTerminalID
0x0101 wTerminalType (USB Streaming)
0x00 bAssocTerminal
0x15 bSourceID
0x00 iTerminal
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x01 bInterfaceNumber
0x00 bAlternateSetting
0x00 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x02 bInterfaceSubClass (Audio Streaming Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x01 bInterfaceNumber
0x01 bAlternateSetting
0x02 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x02 bInterfaceSubClass (Audio Streaming Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
AS Interface Descriptor:
------------------------------
0x07 bLength
0x24 bDescriptorType
0x01 bDescriptorSubtype
0x12 bTerminalLink
0x01 bDelay
0x0001 wFormatTag (PCM)
AS Format Type 1 Descriptor:
------------------------------
0x0B bLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x01 bFormatType (FORMAT_TYPE_1)
0x02 bNrChannels (2 channels)
0x02 bSubframeSize
0x10 bBitResolution (16 bits per sample)
0x01 bSamFreqType (Discrete sampling frequencies)
0x00BB80 tSamFreq(1) (48000 Hz)
Endpoint Descriptor (Audio/MIDI 1.0):
------------------------------
0x09 bLength
0x05 bDescriptorType
0x01 bEndpointAddress (OUT endpoint 1)
0x05 bmAttributes (Transfer: Isochronous / Synch: Asynchronous / Usage: Data)
0x00C4 wMaxPacketSize (1 x 196 bytes)
0x01 bInterval (1 frames)
0x00 bRefresh
0x81 bSynchAddress
AS Isochronous Data Endpoint Descriptor:
------------------------------
0x07 bLength
0x25 bDescriptorType
0x01 bDescriptorSubtype
0x00 bmAttributes
0x00 bLockDelayUnits (undefined)
0x0000 wLockDelay
Endpoint Descriptor (Audio/MIDI 1.0):
------------------------------
0x09 bLength
0x05 bDescriptorType
0x81 bEndpointAddress (IN endpoint 1)
0x01 bmAttributes (Transfer: Isochronous / Synch: None / Usage: Data)
0x0003 wMaxPacketSize (1 x 3 bytes)
0x01 bInterval (1 frames)
0x07 bRefresh
0x00 bSynchAddress
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x02 bInterfaceNumber
0x00 bAlternateSetting
0x00 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x02 bInterfaceSubClass (Audio Streaming Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x02 bInterfaceNumber
0x01 bAlternateSetting
0x01 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x02 bInterfaceSubClass (Audio Streaming Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
AS Interface Descriptor:
------------------------------
0x07 bLength
0x24 bDescriptorType
0x01 bDescriptorSubtype
0x13 bTerminalLink
0x01 bDelay
0x0001 wFormatTag (PCM)
AS Format Type 1 Descriptor:
------------------------------
0x0B bLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x01 bFormatType (FORMAT_TYPE_1)
0x02 bNrChannels (2 channels)
0x02 bSubframeSize
0x10 bBitResolution (16 bits per sample)
0x01 bSamFreqType (Discrete sampling frequencies)
0x00BB80 tSamFreq(1) (48000 Hz)
Endpoint Descriptor (Audio/MIDI 1.0):
------------------------------
0x09 bLength
0x05 bDescriptorType
0x82 bEndpointAddress (IN endpoint 2)
0x01 bmAttributes (Transfer: Isochronous / Synch: None / Usage: Data)
0x00C0 wMaxPacketSize (1 x 192 bytes)
0x01 bInterval (1 frames)
0x00 bRefresh
0x00 bSynchAddress
AS Isochronous Data Endpoint Descriptor:
------------------------------
0x07 bLength
0x25 bDescriptorType
0x01 bDescriptorSubtype
0x00 bmAttributes
0x00 bLockDelayUnits (undefined)
0x0000 wLockDelay
Microsoft OS Descriptor is not available. Error code: 0x0000001F
String Descriptor Table
--------------------------------
Index LANGID String
0x00 0x0000 0x0409
0x01 0x0409 "STMicroelectronics"
0x02 0x0409 "STM32 AUDIO Streaming in FS Mode"
0x03 0x0409 "368932633438"
------------------------------
Connection path for device:
USB xHCI Compliant Host Controller
Root Hub
STM32 AUDIO Streaming in FS Mode (VID=0x0483 PID=0x5730) Port: 5
Running on: Windows 10 or greater (Build Version 19043)
Brought to you by TDD v2.15.0, Jun 8 2020, 17:18:07
And here is the modified descriptor:
Information for device STM32 AUDIO Streaming in FS Mode (VID=0x0483 PID=0x5730):
Connection Information:
------------------------------
Device current bus speed: FullSpeed
Device supports USB 1.1 specification
Device supports USB 2.0 specification
Device address: 0x001B
Current configuration value: 0x01
Number of open pipes: 1
Device Descriptor:
------------------------------
0x12 bLength
0x01 bDescriptorType
0x0200 bcdUSB
0x00 bDeviceClass
0x00 bDeviceSubClass
0x00 bDeviceProtocol
0x40 bMaxPacketSize0 (64 bytes)
0x0483 idVendor
0x5730 idProduct
0x0200 bcdDevice
0x01 iManufacturer "STMicroelectronics"
0x02 iProduct "STM32 AUDIO Streaming in FS Mode"
0x03 iSerialNumber "368932633438"
0x01 bNumConfigurations
Configuration Descriptor:
------------------------------
0x09 bLength
0x02 bDescriptorType
0x00D4 wTotalLength (212 bytes)
0x03 bNumInterfaces
0x01 bConfigurationValue
0x00 iConfiguration
0xC0 bmAttributes (Self-powered Device)
0x32 bMaxPower (100 mA)
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x00 bInterfaceNumber
0x00 bAlternateSetting
0x01 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x01 bInterfaceSubClass (Audio Control Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
AC Interface Header Descriptor:
------------------------------
0x0A bLength
0x24 bDescriptorType
0x01 bDescriptorSubtype
0x0100 bcdADC
0x0048 wTotalLength (72 bytes)
0x02 bInCollection
0x01 baInterfaceNr(1)
0x02 baInterfaceNr(2)
AC Input Terminal Descriptor:
------------------------------
0x0C bLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x12 bTerminalID
0x0101 wTerminalType (USB Streaming)
0x00 bAssocTerminal
0x02 bNrChannels (2 channels)
0x0003 wChannelConfig
0x00 iChannelNames
0x00 iTerminal
AC Feature Unit Descriptor:
------------------------------
0x0A bLength
0x24 bDescriptorType
0x06 bDescriptorSubtype
0x16 bUnitID
0x12 bSourceID
0x01 bControlSize
bmaControls:
0x03 Channel(0) - Mute / Volume
0x00 Channel(1)
0x00 Channel(2)
0x00 iFeature
AC Output Terminal Descriptor:
------------------------------
0x09 bLength
0x24 bDescriptorType
0x03 bDescriptorSubtype
0x14 bTerminalID
0x0301 wTerminalType (Speaker)
0x00 bAssocTerminal
0x16 bSourceID
0x00 iTerminal
AC Input Terminal Descriptor:
------------------------------
0x0C bLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x11 bTerminalID
0x0201 wTerminalType (Microphone)
0x00 bAssocTerminal
0x02 bNrChannels (2 channels)
0x0003 wChannelConfig
0x00 iChannelNames
0x00 iTerminal
AC Feature Unit Descriptor:
------------------------------
0x0A bLength
0x24 bDescriptorType
0x06 bDescriptorSubtype
0x15 bUnitID
0x11 bSourceID
0x01 bControlSize
bmaControls:
0x03 Channel(0) - Mute / Volume
0x00 Channel(1)
0x00 Channel(2)
0x00 iFeature
AC Output Terminal Descriptor:
------------------------------
0x09 bLength
0x24 bDescriptorType
0x03 bDescriptorSubtype
0x13 bTerminalID
0x0101 wTerminalType (USB Streaming)
0x00 bAssocTerminal
0x15 bSourceID
0x00 iTerminal
Endpoint Descriptor (Audio/MIDI 1.0):
------------------------------
0x09 bLength
0x05 bDescriptorType
0x83 bEndpointAddress (IN endpoint 3)
0x03 bmAttributes (Transfer: Interrupt / Synch: None / Usage: Data)
0x0002 wMaxPacketSize (1 x 2 bytes)
0x0A bInterval (10 frames)
0x00 bRefresh
0x00 bSynchAddress
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x01 bInterfaceNumber
0x00 bAlternateSetting
0x00 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x02 bInterfaceSubClass (Audio Streaming Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x01 bInterfaceNumber
0x01 bAlternateSetting
0x02 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x02 bInterfaceSubClass (Audio Streaming Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
AS Interface Descriptor:
------------------------------
0x07 bLength
0x24 bDescriptorType
0x01 bDescriptorSubtype
0x12 bTerminalLink
0x01 bDelay
0x0001 wFormatTag (PCM)
AS Format Type 1 Descriptor:
------------------------------
0x0B bLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x01 bFormatType (FORMAT_TYPE_1)
0x02 bNrChannels (2 channels)
0x02 bSubframeSize
0x10 bBitResolution (16 bits per sample)
0x01 bSamFreqType (Discrete sampling frequencies)
0x00BB80 tSamFreq(1) (48000 Hz)
Endpoint Descriptor (Audio/MIDI 1.0):
------------------------------
0x09 bLength
0x05 bDescriptorType
0x01 bEndpointAddress (OUT endpoint 1)
0x05 bmAttributes (Transfer: Isochronous / Synch: Asynchronous / Usage: Data)
0x00C4 wMaxPacketSize (1 x 196 bytes)
0x01 bInterval (1 frames)
0x00 bRefresh
0x81 bSynchAddress
AS Isochronous Data Endpoint Descriptor:
------------------------------
0x07 bLength
0x25 bDescriptorType
0x01 bDescriptorSubtype
0x00 bmAttributes
0x00 bLockDelayUnits (undefined)
0x0000 wLockDelay
Endpoint Descriptor (Audio/MIDI 1.0):
------------------------------
0x09 bLength
0x05 bDescriptorType
0x81 bEndpointAddress (IN endpoint 1)
0x01 bmAttributes (Transfer: Isochronous / Synch: None / Usage: Data)
0x0003 wMaxPacketSize (1 x 3 bytes)
0x01 bInterval (1 frames)
0x07 bRefresh
0x00 bSynchAddress
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x02 bInterfaceNumber
0x00 bAlternateSetting
0x00 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x02 bInterfaceSubClass (Audio Streaming Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
Interface Descriptor:
------------------------------
0x09 bLength
0x04 bDescriptorType
0x02 bInterfaceNumber
0x01 bAlternateSetting
0x01 bNumEndPoints
0x01 bInterfaceClass (Audio Device Class)
0x02 bInterfaceSubClass (Audio Streaming Interface)
0x00 bInterfaceProtocol (Audio Protocol undefined)
0x00 iInterface
AS Interface Descriptor:
------------------------------
0x07 bLength
0x24 bDescriptorType
0x01 bDescriptorSubtype
0x13 bTerminalLink
0x01 bDelay
0x0001 wFormatTag (PCM)
AS Format Type 1 Descriptor:
------------------------------
0x0B bLength
0x24 bDescriptorType
0x02 bDescriptorSubtype
0x01 bFormatType (FORMAT_TYPE_1)
0x02 bNrChannels (2 channels)
0x02 bSubframeSize
0x10 bBitResolution (16 bits per sample)
0x01 bSamFreqType (Discrete sampling frequencies)
0x00BB80 tSamFreq(1) (48000 Hz)
Endpoint Descriptor (Audio/MIDI 1.0):
------------------------------
0x09 bLength
0x05 bDescriptorType
0x82 bEndpointAddress (IN endpoint 2)
0x01 bmAttributes (Transfer: Isochronous / Synch: None / Usage: Data)
0x00C0 wMaxPacketSize (1 x 192 bytes)
0x01 bInterval (1 frames)
0x00 bRefresh
0x00 bSynchAddress
AS Isochronous Data Endpoint Descriptor:
------------------------------
0x07 bLength
0x25 bDescriptorType
0x01 bDescriptorSubtype
0x00 bmAttributes
0x00 bLockDelayUnits (undefined)
0x0000 wLockDelay
Microsoft OS Descriptor is not available. Error code: 0x0000001F
String Descriptor Table
--------------------------------
Index LANGID String
0x00 0x0000 0x0409
0x01 0x0409 "STMicroelectronics"
0x02 0x0409 "STM32 AUDIO Streaming in FS Mode"
0x03 0x0409 "368932633438"
------------------------------
Connection path for device:
USB xHCI Compliant Host Controller
Root Hub
STM32 AUDIO Streaming in FS Mode (VID=0x0483 PID=0x5730) Port: 5
Running on: Windows 10 or greater (Build Version 19043)
Brought to you by TDD v2.15.0, Jun 8 2020, 17:18:07
The changes I've made are:
Add AC Interrupt endpoint descriptor.
Change wTotalLength in Configuration Descriptor.
Change bNumEndPoints in AC Interface descriptor from 0 to 1.
USB device seems to enumerate fine and there is audio, however when looking at the output of Beagle USB logic analyzer, I don't see any data being requested by the host from the interrupt endpoint. So my question is, is there something wrong with the way I modified the descriptors or is it something else? Has anyone managed to get the Status Interrupt Endpoint working properly for USB audio devices?
Running on: Windows 10 or greater (Build Version 19043)
Windows doesn't handle this interrupt in my experience. Try it on Linux or MacOS.
I have a digital caliper and want to receave the output data via usb, with no result so far
Here is what I tried:
after reading the docs pyusb
I need to useread() function for this type of data.
so I need to find the correct endpoint address first
import usb.core
import usb.util
dev = usb.core.find(idVendor=0x0403, idProduct=0x6001)
ENDPOINT 0x81: Bulk IN ===============================
bEndpointAddress : 0x81 IN # Endpoint in
wMaxPacketSize : 0x40 (64 bytes)
The second parameter is the data payload (write) or the number of bytes to read (read)
Im not sure but I assume its wMaxPacketSize : 0x40 (64 bytes)
for the time out argument I use the Device.default_timeout property as the operation timeout .
so I wrote a loop to wait for receaving data
import usb.core
import usb.util
dev = usb.core.find(idVendor=0x0403, idProduct=0x6001)
while True:
ret = dev.read(0x81, 0x44 )
print(ret)
and got a raise USBError(_strerror(ret), ret, _libusb_errno[ret])
usb.core.USBError: [Errno 10060] Operation timed out
What am I missing here?
Full Device Desription
DEVICE ID 0403:6001 on Bus 001 Address 007 =================
bLength : 0x12 (18 bytes)
bDescriptorType : 0x1 Device
bcdUSB : 0x200 USB 2.0
bDeviceClass : 0x0 Specified at interface
bDeviceSubClass : 0x0
bDeviceProtocol : 0x0
bMaxPacketSize0 : 0x8 (8 bytes)
idVendor : 0x0403
idProduct : 0x6001
bcdDevice : 0x400 Device 4.0
iManufacturer : 0x1 MAHR
iProduct : 0x2 16EXu
iSerialNumber : 0x3 MAO74LCR
bNumConfigurations : 0x1
CONFIGURATION 1: 44 mA ===================================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x2 Configuration
wTotalLength : 0x20 (32 bytes)
bNumInterfaces : 0x1
bConfigurationValue : 0x1
iConfiguration : 0x0
bmAttributes : 0xa0 Bus Powered, Remote Wakeup
bMaxPower : 0x16 (44 mA)
INTERFACE 0: Vendor Specific ===========================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x4 Interface
bInterfaceNumber : 0x0
bAlternateSetting : 0x0
bNumEndpoints : 0x2
bInterfaceClass : 0xff Vendor Specific
bInterfaceSubClass : 0xff
bInterfaceProtocol : 0xff
iInterface : 0x2 16EXu
ENDPOINT 0x81: Bulk IN ===============================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x81 IN
bmAttributes : 0x2 Bulk
wMaxPacketSize : 0x40 (64 bytes)
bInterval : 0x0
ENDPOINT 0x2: Bulk OUT ===============================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x2 OUT
bmAttributes : 0x2 Bulk
wMaxPacketSize : 0x40 (64 bytes)
bInterval : 0x0
Why am I getting the "Operation not supported or unimplemented on this platform" message?
I am running windows 10 64 bit and have installed python 3.7 64 bit, pyusb 1.0.2 and libusb-1.0.22.7z. For libusb-1.0.22.7z I unzipped it and copied the MS64\dll\libusb-1.0.dll to C:\Users..\AppData\Local\Programs\Python\Python37\ folder.
import usb
device = usb.core.find(idVendor = 0x0461, idProduct = 0x4d65) #mouse
if device is None:
raise ValueError('No device')
print(device)
interface = 0
if device.is_kernel_driver_active(interface):
print("kernel driver active")
The output is:
DEVICE ID 0461:4d65 on Bus 008 Address 002 =================
bLength : 0x12 (18 bytes)
bDescriptorType : 0x1 Device
bcdUSB : 0x200 USB 2.0
bDeviceClass : 0x0 Specified at interface
bDeviceSubClass : 0x0
bDeviceProtocol : 0x0
bMaxPacketSize0 : 0x8 (8 bytes)
idVendor : 0x0461
idProduct : 0x4d65
bcdDevice : 0x200 Device 2.0
iManufacturer : 0x0
iProduct : 0x2 USB Optical Mouse
iSerialNumber : 0x0
bNumConfigurations : 0x1
CONFIGURATION 1: 98 mA ===================================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x2 Configuration
wTotalLength : 0x22 (34 bytes)
bNumInterfaces : 0x1
bConfigurationValue : 0x1
iConfiguration : 0x0
bmAttributes : 0xa0 Bus Powered, Remote Wakeup
bMaxPower : 0x31 (98 mA)
INTERFACE 0: Human Interface Device ====================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x4 Interface
bInterfaceNumber : 0x0
bAlternateSetting : 0x0
bNumEndpoints : 0x1
bInterfaceClass : 0x3 Human Interface Device
bInterfaceSubClass : 0x1
bInterfaceProtocol : 0x2
iInterface : 0x0
ENDPOINT 0x81: Interrupt IN ==========================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x81 IN
bmAttributes : 0x3 Interrupt
wMaxPacketSize : 0x6 (6 bytes)
bInterval : 0xa
Traceback (most recent call last):
File "c:\Users\me\Documents\Python\usb\usb test.py", line 16, in <module>
if device.is_kernel_driver_active(interface):
File "C:\Users\me\AppData\Local\Programs\Python\Python37\lib\site-packages\usb\core.py", line 1064, in is_kernel_driver_active
interface)
File "C:\Users\me\AppData\Local\Programs\Python\Python37\lib\site-packages\usb\backend\libusb1.py", line 898, in is_kernel_driver_active
intf)))
File "C:\Users\me\AppData\Local\Programs\Python\Python37\lib\site-packages\usb\backend\libusb1.py", line 593, in _check
raise NotImplementedError(_strerror(ret))
NotImplementedError: Operation not supported or unimplemented on this platform
I'm working on a small Python script on a raspberry that interacts with an external device.
that external device has either RS232 and USB ports and I'm using it through the USB port.
lsusb shows:
Bus 001 Device 004: ID 0665:5161 Cypress Semiconductor USB to Serial
So i guess that the USB port in the embedded device internally has a USB to Serial converter.
Till there everything is fine, except that when I open the device through PyUSB I can only get an IN endpoint (0x81) but not an OUT endpoint.
So I decided to inspect through lsusb -v:
Bus 001 Device 004: ID 0665:5161 Cypress Semiconductor USB to Serial
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x0665 Cypress Semiconductor
idProduct 0x5161 USB to Serial
bcdDevice 0.02
iManufacturer 3 (error)
iProduct 1 (error)
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 34
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 0 No Subclass
bInterfaceProtocol 0 None
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.11
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 27
Report Descriptor: (length is 27)
Item(Global): Usage Page, data= [ 0x00 0xff ] 65280
(null)
Item(Local ): Usage, data= [ 0x01 ] 1
(null)
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Local ): Usage, data= [ 0x02 ] 2
(null)
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0xff 0x00 ] 255
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x82 ] 130
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Volatile Bitfield
Item(Local ): Usage, data= [ 0x02 ] 2
(null)
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Main ): Output, data= [ 0x82 ] 130
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Volatile Bitfield
Item(Main ): End Collection, data=none
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 12
Device Status: 0x0000
(Bus Powered)
There is only one configuration, one interface, one endpoint and that's marked as IN. Is that possible?
Thanks in advance!
This hint is:
bInterfaceClass 3 Human Interface Device
HID transports data to the PC (IN) via an interrupt endpoint. The reverse direction uses the default control endpoint (EP0).
So i guess that the USB port in the embedded device internally has a USB to Serial converter.
While this may be the case, it uses an unusual configuration. The HID protocol won't require (OEM) drivers on a PC, but has much lower limits on data rates- which is OK for devices like an UPS.
TL;DR Just access the device like any other HID device with pyUSB, and use control messages for the OUT (Pi=>device) direction.
I'm trying to send/receive audio over USB from my embedded linux device to/from a Windows host.
I understand there are 2 protocols to send audio over USB - USB Audio Class 1 and 2 (UAC1 & UAC2). I found them explained here: http://www.thewelltemperedcomputer.com/HW/USB_Audio.htm.
I have currently used the existing UAC1 device driver in Linux to get audio from the host PC. It works for me. I am now trying to change the device driver to also be capable of sending audio to the host PC.
I see that there's a UAC2 driver (in the latest Linux kernel) that both sends and receives audio from the host. But I'd like to have a UAC1 driver that does that, so that I don't have to install any extra drivers on the Windows host (especially ones I have to buy: http://www.thesycon.de/eng/usb_audiodriver.shtml).
I've modified the linux device driver at linux/drivers/usb/gadget/f_audio.c (I'm using an older kernel). I've changed the USB header descriptor to include the extra endpoint for sending audio to host.
static struct usb_descriptor_header *hs_audio_desc[] = {
(struct usb_descriptor_header *)&std_ac_if_desc,
(struct usb_descriptor_header *)&ac_hdr_desc,
(struct usb_descriptor_header *)&usb_it_desc,
(struct usb_descriptor_header *)&usb_ot_desc,
(struct usb_descriptor_header *)&std_as_out_if0_desc,
(struct usb_descriptor_header *)&std_as_out_if1_desc,
(struct usb_descriptor_header *)&as_out_hdr_desc,
(struct usb_descriptor_header *)&as_out_fmt1_desc,
(struct usb_descriptor_header *)&hs_epout_desc,
(struct usb_descriptor_header *)&as_iso_out_desc,
(struct usb_descriptor_header *)&std_as_in_if0_desc,
(struct usb_descriptor_header *)&std_as_in_if1_desc,
(struct usb_descriptor_header *)&as_in_hdr_desc,
(struct usb_descriptor_header *)&as_in_fmt1_desc,
(struct usb_descriptor_header *)&hs_epin_desc,
(struct usb_descriptor_header *)&as_iso_in_desc,
NULL,
};
The OUT endpoint is defined as:
struct usb_endpoint_descriptor hs_epout_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
.wMaxPacketSize = __constant_cpu_to_le16(OUT_EP_MAX_PACKET_SIZE),
.bInterval = 4,
};
The IN endpoint is defined as:
struct usb_endpoint_descriptor hs_epin_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
.wMaxPacketSize = __constant_cpu_to_le16(OUT_EP_MAX_PACKET_SIZE),
.bInterval = 4,
};
In epautoconf.c, the bEndpointAddress field is usually OR'ed with the endpoint number. I see in my case that this is happening.
The 'bEndpointAddress' field for my OUT endpoint is 0x01 and for my IN endpoint is 0x81 when I print it in epautoconf.c.
I'm however not able to see it on the host side. On my Windows PC, I use USB View tool to see the descriptors and I see that the values are 0x00 and 0x80.
What could have possibly changed the value of bEndpointAdress?
These are the USB descriptors I see in Windows using USB View tool:
Device Descriptor:
bcdUSB: 0x0200
bDeviceClass: 0x00
bDeviceSubClass: 0x00
bDeviceProtocol: 0x00
bMaxPacketSize0: 0x40 (64)
idVendor: 0x1D6B
idProduct: 0x0101
bcdDevice: 0x0316
iManufacturer: 0x01
0x0409: "Linux 3.2.0 with musb-hdrc"
iProduct: 0x02
0x0409: "Linux USB Audio Gadget"
iSerialNumber: 0x00
bNumConfigurations: 0x01
ConnectionStatus: DeviceConnected
Current Config Value: 0x01
Device Bus Speed: High
Device Address: 0x13
Open Pipes: 0
Configuration Descriptor:
wTotalLength: 0x0095
bNumInterfaces: 0x03
bConfigurationValue: 0x01
iConfiguration: 0x00
bmAttributes: 0xC0 (Bus Powered Self Powered )
MaxPower: 0x01 (2 Ma)
Interface Descriptor:
bInterfaceNumber: 0x00
bAlternateSetting: 0x00
bNumEndpoints: 0x00
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x01 (Audio Control)
bInterfaceProtocol: 0x00
iInterface: 0x04
0x0409: "Topology Control"
Audio Control Interface Header Descriptor:
bLength: 0x0A
bDescriptorType: 0x24
bDescriptorSubtype: 0x01
bcdADC: 0x0100
wTotalLength: 0x001F
bInCollection: 0x02
baInterfaceNr[1]: 0x01
baInterfaceNr[2]: 0x02
Audio Control Input Terminal Descriptor:
bLength: 0x0C
bDescriptorType: 0x24
bDescriptorSubtype: 0x02
bTerminalID: 0x02
wTerminalType: 0x0201 (Microphone)
bAssocTerminal: 0x00
bNrChannels: 0x02
wChannelConfig: 0x0003
iChannelNames: 0x00
iTerminal: 0x07
Audio Control Output Terminal Descriptor:
bLength: 0x09
bDescriptorType: 0x24
bDescriptorSubtype: 0x03
bTerminalID: 0x01
wTerminalType: 0x0301 (Speaker)
bAssocTerminal: 0x00
bSoruceID: 0x00
iTerminal: 0x09
Interface Descriptor:
bInterfaceNumber: 0x01
bAlternateSetting: 0x00
bNumEndpoints: 0x00
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x02 (Audio Streaming)
bInterfaceProtocol: 0x00
iInterface: 0x0B
0x0409: "Playback Inactive"
Interface Descriptor:
bInterfaceNumber: 0x01
bAlternateSetting: 0x01
bNumEndpoints: 0x01
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x02 (Audio Streaming)
bInterfaceProtocol: 0x00
iInterface: 0x0C
0x0409: "Playback Active"
Audio Streaming Class Specific Interface Descriptor:
bLength: 0x07
bDescriptorType: 0x24
bDescriptorSubtype: 0x01
bTerminalLink: 0x01
bDelay: 0x01
wFormatTag: 0x0001 (PCM)
Audio Streaming Format Type Descriptor:
bLength: 0x0B
bDescriptorType: 0x24
bDescriptorSubtype: 0x02
bFormatType: 0x01
bNrChannels: 0x00
bSubframeSize: 0x02
bBitResolution: 0x10
bSamFreqType: 0x01
tSamFreq[1]: 0x00BB80 (48000 Hz)
Endpoint Descriptor:
bEndpointAddress: 0x00 OUT
Transfer Type: Isochronous
wMaxPacketSize: 0x00C8 (200)
bInterval: 0x04
Audio Streaming Class Specific Audio Data Endpoint Descriptor:
bLength: 0x07
bDescriptorType: 0x25
bDescriptorSubtype: 0x01
bmAttributes: 0x00
bLockDelayUnits: 0x00
wLockDelay: 0x0000
Interface Descriptor:
bInterfaceNumber: 0x02
bAlternateSetting: 0x00
bNumEndpoints: 0x00
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x02 (Audio Streaming)
bInterfaceProtocol: 0x00
iInterface: 0x0D
0x0409: "Capture Inactive"
Interface Descriptor:
bInterfaceNumber: 0x02
bAlternateSetting: 0x01
bNumEndpoints: 0x01
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x02 (Audio Streaming)
bInterfaceProtocol: 0x00
iInterface: 0x0E
0x0409: "Capture Active"
Audio Streaming Class Specific Interface Descriptor:
bLength: 0x07
bDescriptorType: 0x24
bDescriptorSubtype: 0x01
bTerminalLink: 0x02
bDelay: 0x01
wFormatTag: 0x0001 (PCM)
Audio Streaming Format Type Descriptor:
bLength: 0x0B
bDescriptorType: 0x24
bDescriptorSubtype: 0x02
bFormatType: 0x01
bNrChannels: 0x00
bSubframeSize: 0x02
bBitResolution: 0x10
bSamFreqType: 0x01
tSamFreq[1]: 0x00BB80 (48000 Hz)
Endpoint Descriptor:
bEndpointAddress: 0x80 IN
Transfer Type: Isochronous
wMaxPacketSize: 0x00C8 (200)
bInterval: 0x04
Audio Streaming Class Specific Audio Data Endpoint Descriptor:
bLength: 0x07
bDescriptorType: 0x25
bDescriptorSubtype: 0x01
bmAttributes: 0x00
bLockDelayUnits: 0x00
wLockDelay: 0x0000
Why won't Windows install the UAC1 driver?
For my first question, I got an answer from the linux-usb mailing list. It turns out that 'epautoconf.c' does not change 'bEndpointAdress'. So I changed the value in the definition of 'bEndpointAdress' and it is correctly conveyed to the host now.
Windows installs the UAC1 driver correctly when I use this configuration:
ConnectionStatus: DeviceConnected
Current Config Value: 0x01
Device Bus Speed: High
Device Address: 0x11
Open Pipes: 0
Configuration Descriptor:
wTotalLength: 0x00E7
bNumInterfaces: 0x03
bConfigurationValue: 0x01
iConfiguration: 0x00
bmAttributes: 0xC0 (Bus Powered Self Powered )
MaxPower: 0x01 (2 Ma)
Interface Descriptor:
bInterfaceNumber: 0x00
bAlternateSetting: 0x00
bNumEndpoints: 0x00
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x01 (Audio Control)
bInterfaceProtocol: 0x00
iInterface: 0x00
Audio Control Interface Header Descriptor:
bLength: 0x0A
bDescriptorType: 0x24
bDescriptorSubtype: 0x01
bcdADC: 0x0100
wTotalLength: 0x0065
bInCollection: 0x02
baInterfaceNr[1]: 0x01
baInterfaceNr[2]: 0x02
Audio Control Input Terminal Descriptor:
bLength: 0x0C
bDescriptorType: 0x24
bDescriptorSubtype: 0x02
bTerminalID: 0x01
wTerminalType: 0x0201 (Microphone)
bAssocTerminal: 0x00
bNrChannels: 0x02
wChannelConfig: 0x0003
iChannelNames: 0x00
iTerminal: 0x00
Audio Control Feature Unit Descriptor:
bLength: 0x0A
bDescriptorType: 0x24
bDescriptorSubtype: 0x06
bUnitID: 0x02
bSourceID: 0x01
bControlSize: 0x01
bmaControls[0]:
03
bmaControls[1]:
00
bmaControls[2]:
00
iFeature: 0x00
Audio Control Input Terminal Descriptor:
bLength: 0x0C
bDescriptorType: 0x24
bDescriptorSubtype: 0x02
bTerminalID: 0x03
wTerminalType: 0x0402 (Headset)
bAssocTerminal: 0x09
bNrChannels: 0x02
wChannelConfig: 0x0003
iChannelNames: 0x00
iTerminal: 0x00
Audio Control Feature Unit Descriptor:
bLength: 0x0A
bDescriptorType: 0x24
bDescriptorSubtype: 0x06
bUnitID: 0x04
bSourceID: 0x03
bControlSize: 0x01
bmaControls[0]:
03
bmaControls[1]:
00
bmaControls[2]:
00
iFeature: 0x00
Audio Control Selector Unit Descriptor:
bLength: 0x06
bDescriptorType: 0x24
bDescriptorSubtype: 0x05
bUnitID: 0x05
bNrInPins: 0x01
baSourceID[1]: 0x04
iSelector: 0x09
Audio Control Output Terminal Descriptor:
bLength: 0x09
bDescriptorType: 0x24
bDescriptorSubtype: 0x03
bTerminalID: 0x06
wTerminalType: 0x0101 (USB streaming)
bAssocTerminal: 0x00
bSoruceID: 0x05
iTerminal: 0x00
Audio Control Input Terminal Descriptor:
bLength: 0x0C
bDescriptorType: 0x24
bDescriptorSubtype: 0x02
bTerminalID: 0x07
wTerminalType: 0x0101 (USB streaming)
bAssocTerminal: 0x00
bNrChannels: 0x02
wChannelConfig: 0x0003
iChannelNames: 0x00
iTerminal: 0x00
Audio Control Feature Unit Descriptor:
bLength: 0x0A
bDescriptorType: 0x24
bDescriptorSubtype: 0x06
bUnitID: 0x08
bSourceID: 0x0A
bControlSize: 0x01
bmaControls[0]:
01
bmaControls[1]:
02
bmaControls[2]:
02
iFeature: 0x00
Audio Control Output Terminal Descriptor:
bLength: 0x09
bDescriptorType: 0x24
bDescriptorSubtype: 0x03
bTerminalID: 0x09
wTerminalType: 0x0402 (Headset)
bAssocTerminal: 0x03
bSoruceID: 0x08
iTerminal: 0x00
Audio Control Mixer Unit Descriptor:
bLength: 0x0D
bDescriptorType: 0x24
bDescriptorSubtype: 0x04
bUnitID: 0x0A
bNrInPins: 0x02
baSourceID[1]: 0x07
baSourceID[2]: 0x02
bNrChannels: 0x02
wChannelConfig: 0x0003
iChannelNames: 0x00
bmControls:
00
iMixer: 0x00
Interface Descriptor:
bInterfaceNumber: 0x01
bAlternateSetting: 0x00
bNumEndpoints: 0x00
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x02 (Audio Streaming)
bInterfaceProtocol: 0x00
iInterface: 0x00
Interface Descriptor:
bInterfaceNumber: 0x01
bAlternateSetting: 0x01
bNumEndpoints: 0x01
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x02 (Audio Streaming)
bInterfaceProtocol: 0x00
iInterface: 0x00
Audio Streaming Class Specific Interface Descriptor:
bLength: 0x07
bDescriptorType: 0x24
bDescriptorSubtype: 0x01
bTerminalLink: 0x06
bDelay: 0x01
wFormatTag: 0x0001 (PCM)
Audio Streaming Format Type Descriptor:
bLength: 0x0B
bDescriptorType: 0x24
bDescriptorSubtype: 0x02
bFormatType: 0x01
bNrChannels: 0x02
bSubframeSize: 0x02
bBitResolution: 0x10
bSamFreqType: 0x01
tSamFreq[1]: 0x00BB80 (48000 Hz)
Endpoint Descriptor:
bEndpointAddress: 0x01 OUT
Transfer Type: Isochronous
wMaxPacketSize: 0x00C8 (200)
bInterval: 0x04
Audio Streaming Class Specific Audio Data Endpoint Descriptor:
bLength: 0x07
bDescriptorType: 0x25
bDescriptorSubtype: 0x01
bmAttributes: 0x01
bLockDelayUnits: 0x00
wLockDelay: 0x0000
Interface Descriptor:
bInterfaceNumber: 0x02
bAlternateSetting: 0x00
bNumEndpoints: 0x00
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x02 (Audio Streaming)
bInterfaceProtocol: 0x00
iInterface: 0x00
Interface Descriptor:
bInterfaceNumber: 0x02
bAlternateSetting: 0x01
bNumEndpoints: 0x01
bInterfaceClass: 0x01 (Audio)
bInterfaceSubClass: 0x02 (Audio Streaming)
bInterfaceProtocol: 0x00
iInterface: 0x00
Audio Streaming Class Specific Interface Descriptor:
bLength: 0x07
bDescriptorType: 0x24
bDescriptorSubtype: 0x01
bTerminalLink: 0x07
bDelay: 0x01
wFormatTag: 0x0001 (PCM)
Audio Streaming Format Type Descriptor:
bLength: 0x0B
bDescriptorType: 0x24
bDescriptorSubtype: 0x02
bFormatType: 0x01
bNrChannels: 0x02
bSubframeSize: 0x02
bBitResolution: 0x10
bSamFreqType: 0x01
tSamFreq[1]: 0x00BB80 (48000 Hz)
Endpoint Descriptor:
bEndpointAddress: 0x81 IN
Transfer Type: Isochronous
wMaxPacketSize: 0x00C8 (200)
bInterval: 0x04
Audio Streaming Class Specific Audio Data Endpoint Descriptor:
bLength: 0x07
bDescriptorType: 0x25
bDescriptorSubtype: 0x01
bmAttributes: 0x01
bLockDelayUnits: 0x01
wLockDelay: 0x0004