Observations on N900 touchscreen behavior
 

I noticed two interesting things about the touchscreen on the n900:

1. A rudimentry form of MULTITOUCH
2. A type of PRESSURE SENSITIVITY

Here we go....

I. MULTITOUCH
On any of the multiple desktops, perform the following steps:
1: Press and hold your left thumb near the left side of the screen.
2: Without letting go of your left thumb, press and hold your right thumb near the right side of the screen.
3: The screen should now take inputs from both thumbs and jump to an indecicive area in the middle. Now let go of your left thumb, and then your right.
4: The view should have jumped to the next desktop.

II. PRESSURE SENSITIVITY
When you have both thumbs on the screen (in the above situation), vary the pressure from your right (or left) thumb, and notice how the display reacts to the pressure.

I don't know if such a form of multitouch can be exploited to provide useful application, but at the very least, it's a bloody fast way to switch between desktops :)
Cheers

Re: n900 - AN INTERESTING DISCOVERY
 

I believe the limitation isnt the hardware but rather the software at this stage. Word is that the maemo 6 will have multiple input etc. Interesting to see what you discovered though. Perhaps a hack is doable.

Re: n900 - AN INTERESTING DISCOVERY
 

I like that, moving between desktops is quick, and funky

Re: n900 - AN INTERESTING DISCOVERY
 

No, the effects seen here are just a side effect of how resistive touchscreens work. The n900 hardware does not support multitouch.

What's happening is the location of the detected pressure is just changing rapidly (due to the two inputs) causing the swipe. When both fingers are pressed, the screen reads this as an input somewhere between the two, not as two separate inputs. In some cases it might be possible to infer that two fingers are involved, but I think this would be of limited utility.

Useful trick for desktop switching though :)

Re: n900 - AN INTERESTING DISCOVERY
 

I thought a resistive screen meant that pressure was needed to be applied?

Re: n900 - AN INTERESTING DISCOVERY
 

Lol ya...what i meant was that it recognizes the degree of pressure..the harder you press..the closer the display moves toward the respective point

Re: n900 - AN INTERESTING DISCOVERY
 

It's nothing new, all resistive screens behave like that.
Used it on the N97 to scroll faster in Gravity by removing one hand a small time before the other.
It's been exploited on some devices to allow multitouch (the 5800XM had a video uploaded showing it, but nothing else, and it was forgotten.)
Windows Mobile had an app that was being developed for it and exploited the feature, but I've never heard of it since it was announced: http://www.youtube.com/watch?v=A77VD9nKGDw @ 1:28 (iZoom)

Re: n900 - AN INTERESTING DISCOVERY
 

Thanks for the info..Can you check if the n97 screen responds differently to different amounts of pressure? According to engadget, nokia has just filed a similar patent..

Re: n900 - AN INTERESTING DISCOVERY
 

Isn't this just a characteristic of resistive screens? N97 does the same thing.

Though I had always secretly wished, (when Jussi said at ODZ) Maemo 6 will have multitouch and N900 will have Maemo 6 that secretly there's a multitouch screen.

Re: n900 - AN INTERESTING DISCOVERY
 

Yes, again, all resistive screens are affected by pressure, cause it depends on two films pressing on each other, and pressing harder on one area will cause the screen to detect a press there (or closer to it)
My old HP iPAQ HX2795 does the pressure thing too.

As I said before, it is.

Re: n900 - AN INTERESTING DISCOVERY
 

Old news... Like go1dfish and others said, this is how resistive screens work. Old versions of liqbase (pre-N900) included a "fake multitouch" demo, which approximated the location of the second touch input based on the initial (stationary) location and the averaged point provided by the screen. Here's a video.

Unfortunately I don't think so.

I think they've said Maemo 6 will support capacitive screens, meaning we'll likely get multitouch when we get new hardware. Whether or not Maemo 6 will even run on the current hardware, I'm pretty sure the N900 will never have true multitouch because the resistive screen is incapable.

Re: n900 - AN INTERESTING DISCOVERY
 

lcuk had a liqbase demo with that kind of multitouch.

Re: n900 - AN INTERESTING DISCOVERY
 

both "features" you discovered are normal things for resistive touchscreens :rolleyes: :p

this is possible on EVERY device with resistive touchscreens.

Re: n900 - AN INTERESTING DISCOVERY
 

Would be really nice if the N900 had mounted a screen "Stantum" ... a demonstration: http://www.youtube.com/watch?v=Bv3X5...eature=related

--------
sorry for my english xD :p

Re: n900 - AN INTERESTING DISCOVERY
 

The screen generates one centre of pressure which is the weighted sum of all local pressures acting on it. Force platforms work like this but the more common example is the Wii Fit board.

Re: n900 - AN INTERESTING DISCOVERY
 

This effect is the same as the effect you get from touching the mousepad thingie on laptop computers with two fingers, the mouse pointer jumps in the same way.

But still nice way to switch desktops :) and its pretty cool that it reacts to how much pressure you apply on each spot.

Re: n900 - AN INTERESTING DISCOVERY
 

You can observe the same on the N800/N810.

Re: n900 - AN INTERESTING DISCOVERY
 

Joe Pesci save the forum search...
I was about to start a new thread with this same discovery... I did it totally out-of-the-blue also..
I also believe it's just a side-effect of the resistive/single-touch technology underneath.. but this "hack" is indeed a usable one =]

Re: n900 - AN INTERESTING DISCOVERY
 

A number of synaptic touchpads can detect multiple touches:
http://techdigger.wordpress.com/2009...ows-xp-vista7/

I have a multitouch driver working on my laptop in X quite nicely. 2 finger scrolling is quite enjoyable. Not that Im saying the N900 has a multitouch resistive screen (though they do exist, youtube a very nice demo), Im just saying that many laptop trackpads DO support multitiouch :) Additionally I'd like to add that there has been speculation that the N900's touchscreen is a Stantum Multitouch display (http://www.youtube.com/watch?v=n1GCI5B5ntk for a demo). Anyway, no one has confirmed either way that it is or isnt, so I wouldn't outright dismiss the possibility.

Re: n900 - AN INTERESTING DISCOVERY
 

On old n800 firmware pressure sensivity was used. If you press on menu with finger big buttons would appear, if you press with stylo, buttons will be small. On newer versions of firmware this feature was dropped as unneeded and all buttons became big. So pressure control is good, but nobody uses it actually.
May be it can be used for mouse move/click emulation.

Re: n900 - AN INTERESTING DISCOVERY
 

Well, they incorporated a front webcam without use (yet..).
Why not have some more asses down your sleeve ;)

Re: n900 - AN INTERESTING DISCOVERY
 

Without use? Haven't you seen the Mirror app? Admittedly at least on my system the quality is pretty bad, but it does have a use.

Re: n900 - AN INTERESTING DISCOVERY
 

This one is pretty impressive.

Pocket Piano Multitouch for Nokia 5800 and N97

Re: n900 - AN INTERESTING DISCOVERY
 

@JonWW

Pretty impressive !
can't we have the same thing on our n900 ?

Re: Observations on N900 touchscreen behavior
 

Wait wat! :3 are you guys saying that N900 can sense pressure levels? (like the nintendo ds' resistive screen). Holy cow, this would mean that there could be digital painting software, that has pressure sensitive brushes!

Re: Observations on N900 touchscreen behavior
 

MyPaint supported this in diablo, probably similar behavior in Fremantle now that it's been ported.
Xournal also uses this.