python读取usb内容提示路径错误_使用PyUSB读取/写入usb设备时出现问题（超时）
我正在尝试与一个连接到我的Ubuntu16系统(PythonVer2.7.12)的设备接口。当我试图写入设备时，我会收到写入超时(类似于从设备读取)。
根据我所掌握的少量文档，HID接口是在接口3中实现的，除了标准端点(EP)0之外，设备还支持EP4 in(设备到主机)中断传输类型和EP5 OUT(主机到设备)中断传输类型。它还指出USB块基于请求-响应消息对，消息格式为64字节，第一个字节为“操作码”。对于“get version”命令，操作代码为0x02，其余的将被忽略。
我对Python和USB都不熟悉，所以可能有这个错误，但我正在尝试写入“OUT”接口，然后从“IN”接口读取。我注意到，当我把设备插入Ubuntu系统时，我得到了一个新的设备/dev/usb/hiddev0，但似乎无法写入，所以尝试连接到接口3并获取输入/输出接口。
此外，我还添加了我认为是调用PYUSBúDEBUG，但我没有看到比没有它更多的输出。
通过下面的代码，我确实看到了设备，并且得到了一个输入/输出接口，但是读/写总是超时。我不知道我错过了什么。非常感谢你的帮助import usb.core
import usb.util
from usb.core import *
import sys
import os
import binascii
import time
import serial
import itertools
idV = 0x2abf
idP = 0x0505
# doesnt seem to write anything to log?!
os.environ['PYUSB_DEBUG'] = 'debug'
#os.environ['PYUSB_LOG_FILENAME'] = "pyusb.log" #never written
print "finding idVendor = {}, idProduct= {}".format(idV, idP)
device = usb.core.find(idVendor=idV, idProduct=idP)
if device is None:
print ("Device not found")
exit()
# free up the device from the kernal
for cfg in device:
for intf in cfg:
if device.is_kernel_driver_active(intf.bInterfaceNumber):
try:
device.detach_kernel_driver(intf.bInterfaceNumber)
except usb.core.USBError as e:
sys.exit("Could not detach kernel driver from interface({0}): {1}".format(intf.bInterfaceNumber, str(e)))
# try default conf
print "setting configuration"
device.set_configuration()
print "config set"
print "trying to claim device"
try:
usb.util.claim_interface(device, 0)
print "claimed device"
except usb.core.USBError as e:
print "Error occurred claiming " + str(e)
sys.exit("Error occurred on claiming")
print "device claimed"
# get enpoint instance
cfg = device.get_active_configuration()
print "***********"
for intf in cfg:
print "intf= " + str(intf)
print "***********"
# from document:
# The HID interface is implemented on Interface 3, in addition to standard endpoint (er)0, the device supports
# EP4 IN (device to host) interrupt transfer type, and EP5 OUT (host to device) interrupt transfer type
# Note: EP$ seems to come back as 0x84 while EP5 comes back as 0x05
intf = cfg[(3, 0)]
# get the BULK OUT descriptor
epo = usb.util.find_descriptor(
intf,
# match our first out endpoint
custom_match= \
lambda e: \
usb.util.endpoint_direction(e.bEndpointAddress) == \
usb.util.ENDPOINT_OUT)
assert epo is not None
# get the BULK IN descriptor
epi = usb.util.find_descriptor(
intf,
# match our first out endpoint
custom_match= \
lambda e: \
usb.util.endpoint_direction(e.bEndpointAddress) == \
usb.util.ENDPOINT_IN)
assert epi is not None
print "write the data"
# commands are 64 bytes long, first byte is command code, 02 is 'get version', it doesn't need any of the other bytes set
try:
# don't think I can use [0x00]*63 because it will be all pointers to same object?, call them out to be safe
test = [0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
mybuff = b'\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
#device.write(epo,mybuff,1) #timeout on write
#epo.write(mybuff) #timeout on write
epo.write(mybuff.encode('utf-8')) #timeout on write
except usb.core.USBError as e:
print "Write USBError: " + str(e)
sys.exit()
print "done writing"
print "try read?"
try:
#info = device.read(0x84, 8)
info = epo.read(epi.bEndpointAddress,epi.wMaxPacketSize)
except usb.core.USBError as e:
print "Read USBError: " + str(e)
sys.exit()
print "read: " + str(info)
输出：finding idVendor = 10943, idProduct= 1285
setting configuration
config set
trying to claim device
claimed device
device claimed
***********
< skipping audio interfaces>
intf= INTERFACE 3: Human Interface Device ====================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x4 Interface
bInterfaceNumber : 0x3
bAlternateSetting : 0x0
bNumEndpoints : 0x2
bInterfaceClass : 0x3 Human Interface Device
bInterfaceSubClass : 0x0
bInterfaceProtocol : 0x0
iInterface : 0x8 PlaylistControl
ENDPOINT 0x84: Interrupt IN ==========================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x84 IN
bmAttributes : 0x3 Interrupt
wMaxPacketSize : 0x40 (64 bytes)
bInterval : 0xa
ENDPOINT 0x5: Interrupt OUT ==========================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x5 OUT
bmAttributes : 0x3 Interrupt
wMaxPacketSize : 0x40 (64 bytes)
bInterval : 0xa
***********
write the data
Write USBError: [Errno 110] Operation timed out