Build your own touchscreen!

[zephod]

I have recently 'upgraded' my HTPC capabilities using an oldish 19" WS monitor and a touch screen overlay for hometouchsystems.

This is definately easier on some monitors that others but basically by removing the front bezel and cunningly reattatching it with the extra few mm of glass added by the overlay you have your perfect HTPC remote control.

The overlay I purchased worked very well with the "evtouch" open source linux driver available and some fiddling around with xorg.conf has now made it accurate enough to use with a stylus - or just with your finger. Haven't tested the winXP drivers myself but I gather they are fine and come with a config. utility -- handy.

At ~£100 for an overlay and smaller LCD monitors becoming a common obslete gadget lying around people's homes this is a great way to make use of your old kit and add a rediculously cool gadget to your living room.

If people are interested, I'll put together a tute in the next couple of days.

Happy investigating

[amwhite2008]

Do you know if this works for Vista too? Also, does it leave finger prints all over the screen, or glass front? If it works with Vista and doesnt get covered in fingerprints this would be very good for me.

Thanks
Alex

[digit]

If people are interested, I'll put together a tute in the next couple of days.

I'd be very interested in the article, With 17" - 19" monitors becoming affordable second hand on flea bay / forums it would make an excellent remote control

[Kev32]

I'm interested in a tutorial as well! Recently started looking into an HTPC setup

[TAKTAK]

ooooooooooh, this sounds interesting...

do tell

[zephod]

Right. Here goes. I'll try a write something first about the physical act of fitting the touch screen from HTS. Btw, the website, if you were wondering (and you haven't met a search engine before) is at

http://www.hometouchsystems.com/

----

The touchscreen overlay supplied is an approx 4mm sheet of glass with a plastic/wire tab to the one side. The screen I was sent came with little/no instruction but it's not rocket science... Around the edge of the glass can be seen a slightly pearled/mottled area which I assume to be a 'dead-zone'. However, this is only a couple of mm thick so you will have to be careful when mounting the overlay not to have the monitor bezel in contact with any 'active' areas of the screen.

1. Removing the monitor bezel

Obviously, this is easier on some models than others. On my EDGE TKM it was ****ing fiddly to say the least but other monitors in the house are much easier. Generally, the front bezel (thats the plasic casing on the front of your monitor) is attatched by a series of small plastic clips and 2 or more screws. Usually, this can be removed without axing the monitor into it's constituent parts, and will lever off fairly easily once all of the screws and plastic clips have been negotiated.

2. Laying the overlay

You should now have a monitor with half a casing and an exposed LCD screen. Simply lay the overlay ontop of the screen (GENTLY!) so that the overlay is roughly evenly distributed. If you can't work out which way up it needs to go (not sure it would actually matter...) there was some text printed into the glass at the one edge. I made sure this was the right way up - and mine worked - so that might be a good guide to follow. Take the plastic tab and dangle it out to one side.

3. Attatching the cables

The little plastic tab that sticks out fixes to the supplied hardware and cables via fairly obvious means --- ie. it will only fit one way. The thin tab gives you the option of simply dangling it through the smallest of gaps in the case, but for tidiness, it might be possible to move all the hardware inside the casing leaving only the usb cable prodtruding. In my case this was done by breaking one of the ventilation struts on the back of the monitor using pliers - believe it or not, it looks quite tidy!

4. Replacing the bezel (and any other bits of case you fiddled with)

This is probably the tricky bit. Trying to keep the overlay in roughly the correct position whilst making sure the casing fits AND trying to apply no pressure to active areas is very very tough and took myself and a mate several goes. The TKM was very very fiddly though, I hope others will have better luck. The problem is made much worse by the addition of the few mm of thickness due to the overlay. Try to remember to apply screws in even turns across the monitor so as not to apply a torsion. I used a couple of folded paper risers (v.high-tech) to overcome a fairly monitor specific problem. Basically I would recommend working out how easy it is going to be to do something like this before assuming its possible! But I managed.

5. Job done - ish

Now to make it work. Seems like the windows drivers for XP are ok and the config. utility will be a blessing. I assume Vista is much the same. For me, using ubuntu, I couldn't make their drivers work. The last update is a while ago and I'm running 8.04. However, I found a solution. That tute to follow.

[TAKTAK]

hmmmmmmmmmmmm..... now i just need some money

[ACiD303]

How well do they work? I mean, a lot of touchscreen technology out in kiosks are finicky (calibration goes off, not very responsive - certainly not for click and drag purposes, etc.) and this is one designed for home use....I must say I'm somewhat sceptical of the touchscreen (not your tutorial, kudos for that!)

[zephod]

6. Hitting Ubuntu with a stick

This was a fiddle and between a bit of know how and much googling we eventually got something working. I hope to save you some time. As I understand it this driver (family?) runs across many linux platforms, so whatever your HTPC choice, this may help you.

6a. Install the evtouch drivers

sudo apt-get install xserver-xorg-input-evtouch
sudo modprobe evtouch

6b. Edit xorg.conf

sudo gedit /etc/X11/xorg.conf

you then need to add the following lines :-

Section "InputDevice"
Identifier "touchpanel"
Driver "evtouch"
Option "Device" "/dev/input/evtouch_event"
Option "DeviceName" "touchpanel"
# These values proved to be good in my setup
Option "MinX" "140"
Option "MinY" "100"
Option "MaxX" "1882"
Option "MaxY" "1970"
# For some reason the guys at Zalman rotated the touch-surface
Option "Rotate" "CW"
Option "ReportingMode" "Raw"
Option "Emulate3Buttons"
Option "Emulate3Timeout" "50"
Option "SendCoreEvents" "On"
# This option is needed for 8.04, make cursor move more smoothly
Option "MoveLimit" "2"
EndSection

--- I can't find where I originally robbed that from, but when I do I'll acknowledge it.

Those are the near perfect settings in my xorg.conf file. Note the x and y have been reversed, I don't quite know why. Those settings are good for my dual view running at 1368x768. The whole idea of this was to have an identical appearance on both monitors. Hence the use of the 19" WS not any squarer monitor I had lying around.

6c. Calibrating using xorg.conf

Now here's the biggest hint ever. Make sure you have a keyboard shortcut to the command line - otherwise you might have to hit the reset button a lot of times. Perfecting this is a bit of a chore.

As I mentioned before the x and y are the wrong way round. So for your WS monitor you will have a greater max y value than x value. I recommend using values close to your resolution and then just edit them and keep restarting X --- theres the chore.

It seems that if you need the pointer to move towards the edge of the monitor you have to move that number towards the edge of the scale. If this is unclear (as it sounds to me):-

if you press in the middle left and the cursor is too far to the right, the minimum y value (x/y are swapped remember) must be decreased.

if you press at the middle top and the cursor is too low, the maximum x value must be increased.

Basically fiddle until you can fiddle no more.

7. Solution

Not the easiest, but probably one of the most rewarding fixes/breaks/fixes/breaks/fixes I have ever done. Works great now. This with GNOME/Nautlius makes a much better HTPC than mythTV ever did for me - love it!

Please get back to me with success/horror stories!

-- oh, and HTS do offer ready made solutions. I would imagine they are ok but they didn't offer as cost effective solution nor as gooder resolution. Or didn't at time of writing.

[zephod]

How well do they work? I mean, a lot of touchscreen technology out in kiosks are finicky (calibration goes off, not very responsive - certainly not for click and drag purposes, etc.) and this is one designed for home use....I must say I'm somewhat sceptical of the touchscreen (not your tutorial, kudos for that!)

Ok for me so far. Talking about very different resolutions. With mine, using a stylus can easily open even the smallest icons - i have a seriously small toolbar at the top with ff and teminal icons and can hit them 100% of the time. If its working well at 1368x768 I should imagine its a slightly better piece of kit than the electronic voting booth I last saw - lols