我正在尝试使用Python3和pyusb进行一些基本的USB通信，但在写入USB设备时遇到了困难。经过大量研究，我开发了下面的代码，可以毫无错误地识别和声明设备，但当我试图写入设备时，会收到超时。我相信我使用的是正确的端点(HID/Interface0，在任何情况下都尝试过，但没有成功。(FWIW是'*IDN？'是一个SCPI命令，我的愿望是简单地向设备写入SCPI(ASCII(字符串，然后从设备中读取。
关于设备的信息，收到的错误，以及我的示例代码如下。Fyi这一切都在巴斯特/10.4下的R-Pi3+上运行。任何建议都将不胜感激。谢谢
收到运行尝试和错误：
pi@raspberrypi:~/src $ sudo python3 test6.py
Ladybug device found
writing: *IDN?
Traceback (most recent call last):
File "test6.py", line 36, in <module>
dev.write(0x81,msg,1000)
File "/usr/local/lib/python3.7/site-packages/usb/core.py", line 982, in write
self.__get_timeout(timeout)
File "/usr/local/lib/python3.7/site-packages/usb/backend/libusb1.py", line 860, in intr_write
timeout)
File "/usr/local/lib/python3.7/site-packages/usb/backend/libusb1.py", line 938, in __write
_check(retval)
File "/usr/local/lib/python3.7/site-packages/usb/backend/libusb1.py", line 602, in _check
raise USBTimeoutError(_strerror(ret), ret, _libusb_errno[ret])
usb.core.USBTimeoutError: [Errno 110] Operation timed out
设备信息：
DEVICE ID 1a0d:15d8 on Bus 001 Address 004 =================
bLength : 0x12 (18 bytes)
bDescriptorType : 0x1 Device
bcdUSB : 0x200 USB 2.0
bDeviceClass : 0x0 Specified at interface
bDeviceSubClass : 0x0
bDeviceProtocol : 0x0
bMaxPacketSize0 : 0x40 (64 bytes)
idVendor : 0x1a0d
idProduct : 0x15d8
bcdDevice : 0x100 Device 1.0
iManufacturer : 0x1 LadyBug Technologies LLC
iProduct : 0x2 LB5908A
iSerialNumber : 0x3 189546
bNumConfigurations : 0x1
CONFIGURATION 1: 500 mA ==================================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x2 Configuration
wTotalLength : 0x47 (71 bytes)
bNumInterfaces : 0x2
bConfigurationValue : 0x1
iConfiguration : 0x0
bmAttributes : 0x80 Bus Powered
bMaxPower : 0xfa (500 mA)
INTERFACE 0: Human Interface Device ====================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x4 Interface
bInterfaceNumber : 0x0
bAlternateSetting : 0x0
bNumEndpoints : 0x2
bInterfaceClass : 0x3 Human Interface Device
bInterfaceSubClass : 0x0
bInterfaceProtocol : 0x0
iInterface : 0x0
ENDPOINT 0x81: Interrupt IN ==========================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x81 IN
bmAttributes : 0x3 Interrupt
wMaxPacketSize : 0x80 (128 bytes)
bInterval : 0x1
ENDPOINT 0x1: Interrupt OUT ==========================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x1 OUT
bmAttributes : 0x3 Interrupt
wMaxPacketSize : 0x80 (128 bytes)
bInterval : 0x1
INTERFACE 1: Application Specific ======================
bLength : 0x9 (9 bytes)
bDescriptorType : 0x4 Interface
bInterfaceNumber : 0x1
bAlternateSetting : 0x0
bNumEndpoints : 0x3
bInterfaceClass : 0xfe Application Specific
bInterfaceSubClass : 0x3
bInterfaceProtocol : 0x1
iInterface : 0x0
ENDPOINT 0x82: Bulk IN ===============================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x82 IN
bmAttributes : 0x2 Bulk
wMaxPacketSize : 0x200 (512 bytes)
bInterval : 0x0
ENDPOINT 0x2: Bulk OUT ===============================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x2 OUT
bmAttributes : 0x2 Bulk
wMaxPacketSize : 0x200 (512 bytes)
bInterval : 0x0
ENDPOINT 0x83: Interrupt IN ==========================
bLength : 0x7 (7 bytes)
bDescriptorType : 0x5 Endpoint
bEndpointAddress : 0x83 IN
bmAttributes : 0x3 Interrupt
wMaxPacketSize : 0x40 (64 bytes)
bInterval : 0x1
代码：
import usb.core
import usb.util
import time
# find the device
dev = usb.core.find(idVendor=0x1a0d, idProduct=0x15d8)
# was it found?
if dev is None:
raise ValueError('Ladybug device not found')
else:
print ("Ladybug device found")
# required to detach device from OS, othewise I receive a 'device busy' error
for cfg in dev:
for intf in cfg:
if dev.is_kernel_driver_active(intf.bInterfaceNumber):
try:
dev.detach_kernel_driver(intf.bInterfaceNumber)
except usb.core.USBError as e:
sys.exit("Could not detatch kernel driver from interface({0}): {1}".format(intf.bInterfaceNumber, str(e)))
dev.set_configuration()
usb.util.claim_interface(dev, 0)
data = ('null')
msg = "*IDN?rn"
print ("writing: " + msg)
# write the data
dev.write(0x81,msg,1000)
print ("reading...")
data = dev.read(0x1,100,1000)
print (data)
我认为应该是：
# write the data
dev.write(0x02,msg,1000) # bulk out
print ("reading...")`
data = dev.read(0x82,100,1000) # bulk in