Multitouch comparison on the Droid (left) and Nexus One

That at least some Nexus Ones suffer from some apparent problem with the touchscreen is not news. We've pointed out an issue with the keyboard before. And now Taylor from Android and Me has a great video showing the difference in multitouch between the Motorola Droid and the Nexus One (an HTC phone commissioned by Google).

Basically, what you see above is an app that shows where you're touching the screen. the dots you see on the right -- on the Nexus One -- should be hidden under Taylor's thumbs. Obviously, they're not.

But an update to Taylor's post points out at least one reason that's pretty apparent anyway: Those are not the same phones, and they use different screens. Then there's the question of whether we're purely talking about a software or hardware issue. Maybe we'll see a "fix." Maybe there's no fix. Maybe we're all a little too anal about multitouch. We'll see. Anyhoo, Check out the video after the break.

 

Reader comments

Droid's multitouch not the same as Nexus One's (and there's a reason for that)

15 Comments

Maybe we're all a little too anal about multitouch.

Thank God I've managed to stay away from the multitouch Kool-Aid. Double-tap FTW.

I really hope this is not a N1 screen one issue. I doubt it, as most touchscreens should work roughly the same way? I guess we'll see...

Interesting but I wonder whether this is more related to the application rather than what the phone is really recognizing. It is surely possible that the application works properly on some Android phones and not on others. Then again...I don't know much about creating software so...

All I can say is that the pinch-to-zoom that everyone seems so crazy about works just fine on my Nexus One as it does on my 3GS. I barely use it but when I do it works.

Of course pinch to zoom works, in this guy's video the "pinch-zooming" worked, and it would work in any pinch zoom app flawlessly....it's just reading an inverted location for your fingers.

I'm not sure how multi touch works on other HTC phones such as the nexus one, but on my HTC Hero the texts scales to fit the screen. If it works the same on the nexus one that may possibly be a reason why.

Having recently taken the plunge into kernel development for the Droid, I have a little familiarity with the source code for the Android OS's kernel. This looks like a simple case of a bug in the multitouch initialization code. Perhaps the values need to be different in the case of the N1's screen. It probably slipped by due to the N1 not being multitouch-enabled right off the bat.

I suspect it has to be a problem in the following code from the N1's counterpart to the code in ~/src/droid/omap/arch/arm/omap2/board-sholes.c on the Droid (sorry, don't know what the board-*.c file is called on the N1):

.multi_touch_cfg = {
.ctrl = 0x0b,
.x_origin = 0,
.y_origin = 0,
.x_size = 12,
.y_size = 7,
.aks_cfg = 0,
.burst_len = 0x40,
.tch_det_thr = 0x12,
.tch_det_int = 0x2,
.mov_hyst_init = 0xe,
.mov_hyst_next = 0xe,
.mov_filter = 0x9,
.num_touch = 2,
.merge_hyst = 0,
.merge_thresh = 3,
.amp_hyst = 2,
.x_res = 0x0000,
.y_res = 0x0000,
.x_low_clip = 0x00,
.x_high_clip = 0x00,
.y_low_clip = 0x00,
.y_high_clip = 0x00,
},

EDIT: One thing I will never understand though, how is multitouch even useful on a device that is designed to be used one-handed?

Everybody should read this about HTC screens...
http://lukehutch.wordpress.com/2009/01/10/full-working-multitouch-on-the...

Basically, the N1 and other HTC screens work with two single axes of x and y instead of the double axis xy. In other words, it detects your fingers at the edge of the screen with two axes, instead of at the point your finger touches.

that really really sucks. Hopefully it is actually a software issue and with an update to the kernel it will work properly... probably not..

Cyanogen over on the xda forums had this to say: "Interestingly, there is a hack in the framework (which is enabled on the Droid, but not on the N1) that can be enabled by setting config_filterTouchEvents. With it disabled (the default), I get the axis-flipping problem. Enabling it fixes this, but there are still issues with the points "sticking" when they cross."

Looks like it may just be a software issue with the Nexus One, because when this config flag is enabled, it seems to work the same as the Droid does.