To quote: The PS3 uDraw tablet/accessory comes with a USB dongle which shows up as a standard HID device when plugged into a PC, so I threw together some documentation and a "driver"/application to allow using it on a Windows PC as a standard mouse.
Documentation (Where ambiguous, assume little endian.)
There are 0x08 bytes that can be sent on the device's OUT interrupt pipe -- I don't know what these are. There are 0x1B bytes constantly received on the device's IN interrupt pipe, described below:
0x00 Button status information:
0 Set means square is being held down.
1 Set means cross is being held down.
2 Set means cricle is being held down.
3 Set means triangle is being held down.
4 No idea, but it set itself while playing around. More playing around reset it.
5 Unknown / nothing.
6 Unknown / nothing.