Reader [Chad Essley] asked us:
“I’m wondering if the vast knowledge base of HackADay’ers out there might know of some way to turn almost any laptop into a touch screen of some kind. Actually, any surface.”
He has an older Wacom Tablet, and would like to be able to add resistive touch screen capabilities so that he isn’t forced to use the Wacom pen. Being an artist and part time hacker, he even summed up the question in a comic-style post.
We know of tools such as the EZscreen instant touch:
which allow “Clip on Tablet abilities”, however you have to use their pen, which doesnt help with the tablet problem, but may help with your “any monitor” problem. Another solution is to buy a generic touch screen kit (usually on eBay from somewhere in China), and install it yourself. That will work for most laptops and desktop monitors, however we wouldnt recommend using it with your Wacom tablet, as it would probably interfere with the pen functionality. Hak5 recently did an episode on Touchscreen kits, but there are also a number of places all over the internet to find step-by-step how-tos for kits.
We dont think you could use an infrared camera from the side like in your drawing, because it would be very difficult to calibrate (wouldnt be able to tell the difference between cold hands, and hands that are farther away/etc in our opinions). Things like the Microsoft Surface use infrared, but from underneath (which is much easier for machine vision to handle.) A flat, unlit surface (not like a monitor or a tablet) could use something similar to the laser keyboard.
We have also covered a couple of gesture and touch based input tools which may help out anyone willing to take on this task. TISCH is a top-down camera based multi-touch framework, and Scratch Input is a tool for using acoustic signals on a wall or a table to interpret touch and drag motions.
Unfortunately, that is about all the ideas we could come up with, but the Wikipedia page on Wacom tablets might be a good place to start for background information on what could or could not work with this configuration. Hopefully some of our ideas will spark the interests and specialties of our readers, feel free to respond in the comments, or send any ideas to our tip line!
Thanks again to [Chad] for his question, and feel free to send any other ideas for Ask Hack a Day.
