On Tue, Feb 15, 2005 at 07:04:21PM -0500, Dan Streetman wrote: > Hi Vojtech, > > I'm trying to figure out what the best way to calibrate a touch screen is. > I have a 3M touchscreen driven via mtouchusb, and I access it through > evdev. So, I'd like to be able to initiate hardware calibration via evdev > also. But I'm not sure what the best command to send through evdev would > be? All I really see to talk back to the device is FF, but that doesn't > seem to fit a calibration command...?
You should be able to use EV_MSC for that, if you add the implementation to the driver. > FYI, the hardware calibration sequence/command for (simple 2-point) > hardware calibration of the 3M (EXII 5000UC) USB touchscreen is defined in > the spec: > http://www.3m.com/3MTouchSystems/downloads/tecdoc.jhtml > and it's just a single USB Vendor Request. After the request the > touchscreen uses the next 2 touches to do internal hardware calibration. I looked at the spec and IMO the driver shouldn't use the hardware calibration at all and should report the raw coordinates. The computer is much better suited to do the mapping, since it can do more complicated transformations on the data, including rotation by a few degrees if the touchscreen is not perfectly aligned. -- Vojtech Pavlik SuSE Labs, SuSE CR ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
