Final Touch Screen Video

The project is complete!  This may be the last post regarding the touch screen, though it is possible that someday it will get its own mini ITX board.

Also, there was an article about a partnership between AMD and BlueStacks that is making Android apps available on the PC (if you have an AMD chip).  I downloaded one and in its menu there was an option to enable multitouch.

Link to Article
Link to Android Apps Through AMD

Video Sections:

Hardware (off), Hardware (on), CCV Tracking, CCV Calibration, World of Goo,
Piano Flash App, Solitaire, Plants vs Zombies, Fire Flash App, Paint, Paint Flash App, Microsoft Surface Globe, Spore Creature Creator, Cooliris, Photo Flash App, Lemmings (Lemmix), Bejewled, BumpTop, Microsoft Surface Collage, Microsoft Surface Lagoon

Functional Cosmetics

I successfully added the black poster board to the screen face over the past couple of nights.  It will block a lot of the LED light from shining in the user’s eyes.  There will be a border on the back as well, to block the visible light from going to the camera.  I used poster board instead of spray paint because it is much more removable should I change my mind.  Here is the difference between border and no border:

Touch Screen v2 Update 5-6-2012


  • Shell (enclosure) built
  • PS3 eye camera modified with a 2.1mm m12 lens from PeauProductions
  • Laser control assembly mounted
  • Camera mounted
  • Laser safety perimeter built (but not safe yet, needs to be blacked out)
  • Tested and working! (torn down again though so I can black out some parts)

This is a video of the “Fire” flash demo app, I believe it came from the mtmini package.  In the first part of the video it is running in windowed mode, so the touch points are offset.

Photos of the screen after this weekend’s upgrades:

Touch Table v2 Update

I have completed quite a few changes to the touch table lately.  There was a height problem with the lasers – I’m not sure it is completely fixed but it does seem a lot better.  I had to add a layer of thin plexiglass below the screen layer, but not the lasers, in order to effectively lower them.

Other current progress:

  • LCD ribbon board has been mounted
  • LCD PCB has been mounted
  • Laser control assembly created
  • LCD control assembly planned
  • LED ribbon broken (ripped contacts loose…)
  • LED ribbon fixed (reattached contacts…)

Each laser can be turned off or unplugged individually, or all can be turned off or unplugged together.  Also, the laser power supply now has an actual plug.

My next step is to make an assembly to control the LCD and contain all the ports, including the camera.  Here’s a rough view of what it will contain (it may or may not be attached to the laser control assembly).

Touch Table v2

My inverter board died and I had to find another method to edge light the acrylic, so now, the main surface of the table is a back light itself.  There is an LED ribbon around the edge and the edge has been sanded and torched with a MAPP gas torch so it is smooth and transparent.  I’m still working out how to put a barrier around the edge for the lasers and the whole thing is scotch taped together at the moment.

Half-QWERTY (Mirrored) Keyboard

Finally getting around to posting this… a while ago I started work on a “half QWERTY” keyboard or “mirrored” keyboard script.  The script makes the left half of the keyboard equal the right half of the keyboard when the space bar is held down (instead of just pressed).  The idea eventually evolved and I added a few more functions for convenience such as WASD arrow keys, WASD mouse control (basic), and script on/off control.  It’s necessary to be able to turn the script on and off because as a consequence of using the space bar as the modifier for all the keys, there is small delay on some characters that causes problems when typing two-handed.  It is surprisingly easier than expected to learn how to type this way, and in fact it is almost normal.  A few runs through a typing tutor like Mavis Beacon helps a lot though.

Side note, one of the keys in the script calls an application named “Everything”.  Everything is a replacement for windows search.  In Everything, you just start typing the name of what you are looking for and it narrows down the search as you type.  There is no search time, and no index time.  I think it is a brilliant application and it can be downloaded here if you’re interested:

The script was made using AutoHotkey (specifically AutoHotkey_L) and the SciTE4AutoHotkey editor.

*Updates 3/1/15*

-I have relocated the file to my personal site.  It can be downloaded here:

-AutoHotKey_L appears to be the main branch of AutoHotKey now according to its page on GitHub:

-I have created a GitHub repository for the Half-QWERTY project here:

-The AutoHotkey website has moved to:

-The SciTE4AutoHotkey website has moved to:

List of keys and corresponding functions:

LCD Back Light Revival

I finally got tired of my main PC monitor flickering and turning off on me. I decided to open it up and see what the problem was. I suspected bad capacitors, because that is a cause for the symptoms it was experiencing. The screen would “flicker” when first turned on, until it would reach a point that the back light would shut off, but the power would remain on (I could tell because the power light would remain on). Turning the screen off, and back on AGAIN would make it show for a few seconds and shut off once again.  This would go on for about five minutes, after which the screen and back light would both become available and turn on correctly.  So, I pulled the inverter board to take a look.

This is the inverter board from my poor broken Samsung 216BW.

When inspected a little more closely, the problem is as expected and pretty obvious (if you know what to look for).  Puffy, leaky capacitors.  Seriously leaky.

So, it was time to order some parts and bust out the soldering iron.  These kind of capacitors are “Low ESR Electrolytic”.  They can be ordered from places like Parts Express or MCM Electronics, but I got mine from eBay.

Other points of interest:

  • ***BE CAREFUL HANDLING POWER/INVERTER BOARDS***, don’t touch the leads on the giant cap or any other parts that you aren’t sure about.
  • These kinds of capacitors ARE directional, take note of which way they were facing before you remove them (unless the board is marked).  The negative side of the caps are labeled as such.
  • When removing the bad caps, don’t rip them off the board, use the soldering iron on the back side while pulling on the front, one leg at a time if necessary.

Inverter board after repair, with good flat-topped capacitors:

Success!  This did in fact fix my monitor, good as new! Here is a video of the repair process:

Touch Screen StarCraft

I am continually finding new apps/games/uses for my table, and I decided to check out an RTS, namely old school StarCraft.  I think I had heard of someone doing this before.  I never played the game very much so it doesn’t matter to me that it is likely impossible to be competitive without a keyboard.  There are a few other issues though, like panning, resolution, and colors in Win7.

With no mouse and only fingers there is no good way to move the map around by “pushing” the edge of the screen.  You can however tap on the map in the bottom left corner.  Resolution is also an issue as StarCraft only ever ran in 640×480.  I suppose it is only an issue because I haven’t found a launcher that supports windowing and changing resolution.  Currently I’m using “Chaos” if I want to window it.  There is also an issue with the colors on the loading and splash screens in Windows 7, but that is solvable by leaving the windows display settings panel open before launching the game (yes, this is a silly fix but the only one I found that actually works).

Windows 7 Multi Touch HID Driver

My homemade touch table is working very well now, and I got the Win7 HID driver from to work correctly.  I changed some general settings in Windows to make it more usable with a less precise pointer like increasing the window button size, showing large icons everywhere, and setting everything to single-click instead of double.

I am surprised at how many things in Win7 natively support multi touch gestures.  I know the OS is supposed to, but I didn’t expect it to be as integrated.  These are things I have discovered so far:

-explorer windows support pinching – icons shrink to list and expand to tiles or large
-Windows Photo Viewer supports pinching, panning, and rotating
-panning works in explorer windows

FireFox seems to be the best for multi touch so far.  IE has support, and it can be added to Chrome, but FireFox does a better job and it is actually fun to browse the web this way on my table.  Here is a video showing the HID driver in action, and mostly demonstrating the gestures built into Windows Photo Viewer: