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Aim: I have a whiteboard which emulates as mouse. Thus, when you click and drag on the whiteboard it should move the cursor. I want to make a whiteboard work in Ubuntu It works on windows. Device information: the output of cat /proc/bus/input which contains the device information

I: Bus=0003 Vendor=4623 Product=011a Version=0111
N: Name="Hite Board-XXXXXXXX"
P: Phys=usb-0000:00:14.0-1/input0
S: Sysfs=/devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1:1.0/
U: Uniq=
H: Handlers=mouse2 event13
B: PROP=2
B: EV=b
B: KEY=400 0 0 0 0 0
B: ABS=260800000000003

abhishek@vaio:~$ lsusb -d 4623:011a -v Bus 001 Device 012: ID 4623:011a

Couldn't open device, some information will be missing Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x4623 idProduct 0x011a bcdDevice 0.01 iManufacturer 1 iProduct 2 iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 73
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 150mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
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 429 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 8 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x01 EP 1 OUT bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 0 No Subclass bInterfaceProtocol 0 None iInterface 6 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.10 bCountryCode 33 US bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 91 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 1

Since bInterfaceProtocol is None, linux doesn't recognize it as a mouse input device.

What's ideal approach to reverse engineering it from windows to make it work in linux.

Device in windows device manager:

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Edit 1:

abhishek@vaio:~/dev_work/whiteboard/pyusbwhiteboard$ usb-devices | grep -A5 'Vendor=4623 ProdID=011a' | grep Driver
I:  If#= 0 Alt= 0 #EPs= 2 Cls=03(HID  ) Sub=00 Prot=00 Driver=usbfs
I:  If#= 1 Alt= 0 #EPs= 2 Cls=03(HID  ) Sub=00 Prot=00 Driver=usbhid

dmesg output: http://codepad.org/fFtwryw6

1 Answers1

1

I wrote script which was able to do the job. But I had to figure out what the inputs from the device meant.

import sys,pdb
import usb.core
import usb.util
from pymouse import PyMouse

# whiteboard coordinates axis computed by checking the output against strokes
white_board_x_min=(1<<8)+1
white_board_x_max=(127<<8)+255
white_board_y_min=(1<<8)+1
white_board_y_max=(127<<8)+255

white_board_x_diff=white_board_x_max-white_board_x_min
white_board_y_diff=white_board_y_max-white_board_y_min

# mouse handler
m = PyMouse()
x_screen, y_screen = m.screen_size()

# decimal vendor and product values
dev = usb.core.find(idVendor=17955, idProduct=282)

# first endpoint
interface = 0
endpoint = dev[0][(0,0)][0]
# if the OS kernel already claimed the device, which is most likely true
# thanks to http://stackoverflow.com/questions/8218683/pyusb-cannot-set-configuration
if dev.is_kernel_driver_active(interface) is True:
    # tell the kernel to detach
    dev.detach_kernel_driver(interface)
    # claim the device
    usb.util.claim_interface(dev, interface)
mouse_down_event=False
try:    
    while True :
        try:
            data = dev.read(endpoint.bEndpointAddress,endpoint.wMaxPacketSize)
            # click value
            click=data[1] # if it is 7 mouse down else if it is 4 it is mouse up 
            # get the coordinates
            xcor,ycor,dec_x_binary,dec_y_binary=data[4],data[6],data[3],data[5]
            # convert to decimal
            xcor_dec=(xcor<<8)+dec_x_binary
            ycor_dec=(ycor<<8)+dec_y_binary
            # convert to relative screen coordinates
            screen_xcor=int(round((float(xcor_dec-white_board_x_min)/float(white_board_x_diff)) * x_screen))
            screen_ycor=int(round((float(ycor_dec-white_board_y_min)/float(white_board_y_diff)) * y_screen))
            #print "%d, %d"%(xcor_dec,ycor_dec)
            #print "%d, %d"%(screen_xcor,screen_ycor)
            # check if it is valid event
            if xcor_dec!=0 and ycor_dec!=0:
                # move mouse    
                if click==7:
                    # mean mouse down event
                    if mouse_down_event:
                        # drag event
                        # draw a line from previous coordinates
                        m.drag(screen_xcor, screen_ycor)
                    else:
                        # first button press event
                        m.click(screen_xcor, screen_ycor, 1)
                    mouse_down_event=True
                else:
                    # mouse up event
                    # set event type in mouse_down_event
                    # first button press and drag
                    mouse_down_event=False
        except usb.core.USBError as e:
            data = None
            if e.args == ('Operation timed out',):
                continue  
finally:
    # release the device
    usb.util.release_interface(dev, interface)
    # reattach the device to the OS kernel
    dev.attach_kernel_driver(interface)

https://github.com/abhigenie92/pyusbwhiteboard