Reverse engineered NEXIO/iNexio USB touchscreen protocol
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Device description:
T:  Bus=02 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 54 Spd=12  MxCh= 0
D:  Ver= 1.10 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
P:  Vendor=1870 ProdID=0001 Rev= 1.00
S:  Manufacturer=iNexio
S:  Product=iNexio USB
C:* #Ifs= 2 Cfg#= 1 Atr=c0 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=00 Driver=(none)
E:  Ad=83(I) Atr=03(Int.) MxPS=   8 Ivl=255ms
I:* If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=(none)
E:  Ad=01(O) Atr=02(Bulk) MxPS=  64 Ivl=0ms
E:  Ad=82(I) Atr=02(Bulk) MxPS=  64 Ivl=0ms

The device is infra-red touchscreen and capable of simple multi-touch.
The touch packet format is following:
BYTE	DESCRIPTION
0	some flag, e1 means touch, e0 means release, 8x means non-touch data
1-2	(big endian) length of touch data (X+Y)
3-4	(big endian) length of X axis touch data
5-6	(big endian) length of Y axis touch data
7-70	X axis data - each byte can be in range 0-100 (0x00-0x64),
	representing coverage of that part of axis
71-122	Y axis data - same as above

This means that for single touch, there is one high value somewhere on X axis
and another high value somewhere on the Y axis. Two touches at the same moment
produce two high values on both axes - which means that it's not possible to
find exact finger placement, so this multi-touch capability is very limited.