Related
I just bought a new Logitech mouse with tons of customizable buttons on it, and it got me thinking...what if you could use your PPC as a mouse for your PC? That would be the ultimate in customizability!! Think of it...not only would you have a bunch of hard buttons to play with, but you could also have a customized screen for whichever app has the focus on your PC!
I am nowhere near advanced enough to do this, nor do I know if it's even possible...just throwing it out there as an idea for whoever wants to take up the challenge. I figure it could work on most devices because the camera and flash LED are on the opposite side from the screen and buttons, and BT could be the wireless link. Heck, for that amount of customizability in a mouse I'd even settle for a wired USB version :wink:.
Well enough fantasizing for today...
you're talking about using the camera as the optical sensor?
you'd need it on a special mouse mat that emits light of some kind, and I doubt the feedback would be quick enough.
and i wouldn't fancy pushing my expensive xda around on the desk like a mouse.
Right, I was thinking of the camera as the optical sensor, and the flash LED as the light source. I have a XV6700/Apache, and when I turn on the camera and the flash and set it down on my desk, the screen isn't completely dark because the camera isn't flush against the surface...there's still enough space for light from the LED to reach the lens. Obviously this would vary from device to device...but even in cases where it's completely dark, you could put the "mouse" on top of a few mm of clear plastic or plexiglas to give the LED enough room to bounce the light over. Actually, this option might be desirable as it would address your concern about pushing your device around and getting scratches on it.
In fact, now that I'm thinking about it, using plastic/plexiglas might be better for battery life too. Instead of having the flash stay on all the time, the "mouse" could use the ambient room light to detect initial movement, which in turn would trigger a "wake event" for the flash, and then obviously the flash could be timed to turn off after so many seconds of being idle.
I know speed would likely be an issue as far as feedback goes. Sure, it wouldn't be as quick as my new Logitech laser mouse, but in video mode the camera (at least on the Apache) can go up to 19 fps...so perhaps it would be doable. Obviously you're not going to use Photoshop or play Quake with the thing . I was just thinking added convenience for everyday usage.
well all optical mice i've used have gon crazy on shiny surfaces
their cams are even made directly for this purpos
so i would think using the pda as a mouse would mean it would go even more crazy on a shiny surface
try search i recall posts about this in the past
Issues
light souce: prolong usage of you flash is bad. The life span of the flash may be different for different devices, but I'm pretty sure HTC doesn't give you a nice LED flash to be used for more than 30 seconds per usage. There are reports of 'dying' flash after using it as flashlight.
camera (major issue): phone camera is a fix lense camera (there are a few new Nokia/Sony model that arent). Such camera is not able to take clear picture of close distance object. Try taking a picture of something at a range of 3 inches , at best possible light condition. You won't get a decent picture. Even high tech digital camera is not able to take any picture of any object that is in range of less than 3 inches (even with Macro e.g. the flower, mode on). You can't do much 'mous-ing' with blur images.
It is a good idea though.
just an idea, but what about just using it as a touch pad??
dahquim
Very expensive mouse :lol:
Just get an optical RF mouse.. so much cheaper..
Come to think of it, better get a bluetooth mouse that you can use with both your PC and PPC!
Hmm, I don't know. I just imagined a Universal used as a mouse. Not a pretty picture.
Any way, as for the touch pad idea, it's fairly easy to implement, but it doesn't have the resolution to handle even blow average PC screen which is 800x600 pixels.
hanmin said:
Even high tech digital camera is not able to take any picture of any object that is in range of less than 3 inches (even with Macro e.g. the flower, mode on). You can't do much 'mous-ing' with blur images.
Click to expand...
Click to collapse
OK, so let's say you have a clear glass desk and you attach a board underneath it at a distance of 3 inches so it can focus... j/k
levenum said:
as for the touch pad idea, it's fairly easy to implement, but it doesn't have the resolution to handle even blow average PC screen which is 800x600 pixels.
Click to expand...
Click to collapse
I don't think dahquim meant "touch pad" to mean "tablet PC" or a remote touch-screen clone of your PC monitor (you can do that with LogMeIn). I think he meant simply losing the "mouse" functionality and keeping the ability to have the device's screen display "soft buttons" that could execute commands and that would change depending on whichever app has the focus on your PC. That would somewhat relieve one of having to remember different keyboard shortcuts for each different PC app you use. Same idea as the Optimus Keyboard but on a smaller scale.
touchpad.. ?
Touchpad idea is nice - it could work just like touchpads on laptop; ie. moving finger on mobile device screen causes mouse cursor to move on PC screen, tapping mobile device screen causes mouse click.... who'll implement this ? ;-)
hanmin said:
Issues
light souce: prolong usage of you flash is bad. The life span of the flash may be different for different devices, but I'm pretty sure HTC doesn't give you a nice LED flash to be used for more than 30 seconds per usage. There are reports of 'dying' flash after using it as flashlight.
camera (major issue): phone camera is a fix lense camera (there are a few new Nokia/Sony model that arent). Such camera is not able to take clear picture of close distance object. Try taking a picture of something at a range of 3 inches , at best possible light condition. You won't get a decent picture. Even high tech digital camera is not able to take any picture of any object that is in range of less than 3 inches (even with Macro e.g. the flower, mode on). You can't do much 'mous-ing' with blur images.
It is a good idea though.
Click to expand...
Click to collapse
hanmin was right pointing these issues. i'll add some more, from a developer's point of view:
-so you want to have this as a wireless device: think of the power consumption: on one hand you need the camera to be on, with the led, and also a wireless connection for transmitting the data like BT or WiFi.. The baterry wont last long
-even if we cant get the camera to focus at nearly 1-2mm, we could still detect movement of some kind (so the idea would work..in a way or another :roll: ). but please note: there are tens of types of devices, you cant get to make the trick for all.
-it wouldnt be very precise: did you even tried to create an icon? you need to tap over the right pixel, do you think it will work with this?
-ok so you're a fanatic gamer : poor device and poor you, on one hand you'll ruing the device, on the other you'll go nuts because... : slow reaction times, low accuracy...
I see that you've thought about the idea of creating a touchpad out of the pocketpcs. I worked on such a project once. It was indeed interesting. The only problem was that: (issues again)
-the screen is not so sensitive to finger pressure as a touchpad is
-you'll mostly have to use the stilus
But at least this approach is functional.
Regards,
Radu
Yes was thinking more the "set of buttons on [email protected] that let you do quick and easy thinkgs to whatever program your using.
For example, how about being able to switch virtual desktops or having a list of programs on the ppc screen that you switch between... a la Alt-Tab??
just ideas, but of course would be completely customisable (macro buttons)
dahquim
Looks like this guy got the concept up and running on his Nokia...
http://www.pyrofersprojects.com/nokiamouse.php
Hi all.
This has been bugging me for a while.
Does the xperia actually have a accelerometer?
Don't see it mentioned in the white papers or previews.
as far as i know it dont
as you say it's not mentioned and the
prerelease version people have
been reviewing dont seem to
i'd like an accelerometer myself but also the option to turn it off
AFAIK it does.
I'm 95% sure it doesn't. Atleast not the one i've been using.
Didn't the early prototype vids show it having one?
Maybe I'm just thinking of the Diamond...idk
It switches to landscape when you open the keyboard. Otherwise, the pre-release doesn't have an accelerometer.
I used to have a link, but cannot find it anymore, But back when it was announced, there was a video shot with one of SE reps showing off the phone. (i know, there were hundreds!)
At that time he was distinctly talking about the X1 using the front facing cam to pick up and recognise gesture controls. I have since seen a press release(again, lost, sorry, but try ESATO or SENSE) that SE were dealing with a company who specialise in that line of things.
What i do find odd, maybe just my ignorance, is that as similar as HTC Touch Pro, and X1 are internally, how SE did not have the accelerometer installed. Surely it would only add a small amount to the total cost of the phone?
Yeah, even for a consumer to buy a cheap acceleromenter is only like $1, lol
I've got a very technical, but very elemental question on this subject, please forgive me for being such a nerd.
What do I ultimately need an accelerometer for in a phone?
How does this accelerometer function work anyway?
In laptops I can understand it's function to protect the hard drive.
As soon as it detects high accelerations (i.e. "free fall" --> acceleration of 9.81m/s^2 = 1g) it shuts down all moving parts in anticipation of an imminent impact (which because of the sudden stop results in massive accelerations around 1500g and more).
Easy physics, no mystery there...
But in mobile phones an accelerometer is often mentioned in relation to automatically rotating screens and of course apple's famous ball-through-labyrinth-game.
Technically an accelerometer on its own cannot do that. All you get from this device is a statement like
"The velocity of rotation around the phone's z-axis is increasing by 3 rad/square-second."
so in order to know the phone's orientation from that you'd need
1. initial calibration (i.e. tell the phone where "down" and "stop" is every time you turn it on)
2. constant measurement of acceleration on all 6 spacial axes (miss one move and your calibration is off).
As far as I can tell there's no note in the iPhone's Manual saying you may only turn it on when it's sitting on a stationary horizontal surface (so much for initial calibration).
And I can imagine the electronics reading the accelerometer go into a low-power "alarming amplitude only" state too most of the time to preserve battery power. Also you'd have to consider the Earth's rotation and path in that calculation too, since the measurement is rather absolute.
Besides, there are more simple and reliable methods out there to to create an artificial horizon (gravity sensor), so what's the benefit of using an accelerometer in the first place?
So, how do these Phones really know where "down" is to auto-rotate my screen if they use an accelerometer, and why not use something simpler?
The only benefit I see is for car navigation software to use the sensor when the GPS signal vanishes (in tunnels etc.) to extrapolate your course from the last confirmed position and velocity, but as far as I know they don't even use it (yet).
Ok, let's say either:
A) you have a slight factory calibration so it can "guess" which direction.
B) it dynamically calibrates as the phone is held/moved/twisted.
C) It's not near perfect, just a guesstimate of movement.
and
it's just for screen rotation and games
dont believe gps's use it as it's not precise enough
Let me apologize first, because, I know nothing about all that disertation about accelerometers. But let me have my street guy comon sense opinion.
First I don't think these phones have such a sofistcated type of accelerometer. The use of the accelerometer word in mobile phones is a missnomer because I'm sure they have something simpler that I would call it "Balancerometer"
I believe it's just 2 or 3 tubular circles perpendicular to each other. These tiny tubes are filled with some kind of liquid The reading of the position of these liquid is enough to know the position of the device ex: Vertical, horizontal, diagonal at any angle of mesurement. It probably cost no more than $2.00 in mass production.
You know better tha me. Do you think I am crazy or worst?
GSM Arena says
Size 800 x 480 pixels, 3.0 inches
- Full QWERTY keyboard
- Accelerometer sensor for auto-rotate
- Optical joystick navigation
Click to expand...
Click to collapse
http://www.gsmarena.com/sony_ericsson_xperia_x1-2246.php
But then again ... who knows.
In the diamond app forum, Ikari creatied pocket gforce which from the picture, its not just a simple tilt sensor. Even I wonder why we need the full thing.
But cool though.
x1_wp_r3a.pdf manual
I have the manual above. Not sure where I got it from .... but it doesn't mention accelerometer and it is SEs own May 08 X1 whitepaper.
It detailed many things people suggested the X1 didn't have ... like it does have hardware for 3D accelerated graphics and the supporting drivers ... It also cleared up the actual RAM - 256m rather than the oh ... there is some sort of 400m of something.
Intro was as follows :
XPERIA™ is premium brand in the Sony Ericsson portfolio to meet the consumer need for a converged entertainment and mobile Web communication experience. XPERIA™ delivers a premium experience of energized communication - anytime, anywhere, anything and with anyone.
X1 is the first product on the XPERIA™ lineup and introduces new experiences for mobile productivity with an extraordinary new blend of multimedia, enterprise and Web functionality. The need for multiple devices – such as a mobile phone, an e-mail client, a mobile companion for a PC and more – are all met in one device with easy-to-use functionality. A sturdy metal design to withstand everyday use and a ground breaking XPERIA™ panel combine to give a seamless and premium user experience.
Features include:
•3-inch Wide-VGA (800x480) TFT 65K color LCD
•XPERIA™ panel concept
•Unified Media Experience
•3.2-megapixel camera with Touch auto focus
•Video capture and playback up to 30 fps
•Integrated WiFi and A-GPS
•Mobile broadband
•Handsfree headset with a 3.5 mm audio jack, USB charger, USB cable provided in the kit
•Internet Explorer Mobile browser
•HSDPA 7.2Mbps, HSUPA 2Mbps
•Windows Mobile® 6.1 Professional
•YouTube support (3GPP playback)
•FM radio, streaming audio/video
•Video telephony
•Bluetooth™ 2.0
•HW 3D Graphics
•Supports microSD™ High Capacity memory card
•Exchange /IMAP4/POP3 e-mail
•Quad-band EDGE (850/900/1800/1900 MHz)
•Tri-band HSPA X1a850/1900/2100 MHz) X1i900/1900/2100 MHz) )
The slim arc form factor has a large 3-inch Wide-VGA color screen. Memory capacity is up to 400 MB internally and includes a slot for a microSD™ card. The ergonomically designed QWERTY keypad allows you to quickly write text messages, type phone numbers or search for particular content such as pictures or tracks. The user can quickly toggle between different relevant functions, tailored for all situations in life, and use them as active desktop home screens by using the unique XPERIA™ panel concept.
Panel stuff :
•Sony Ericsson panel – a panel to read news, weather, finance, world clock and shortcuts to communication and applications.
•Media Experience panel – center for viewing and playing multimedia files.
•Slideshow panel – slideshow of recently taken videos and photos.
•Microsoft Today panel – this panel is the actual Microsoft today screen.
•3D Fish panel – a panel that showcases the 3D features of the phone; a fish tank with 3D fishes.
•FM radio panel - a panel to access your FM radio straight.
•Google panel - provides access to all GOogle services.
•Customized panels can be offered.
and for me ... to avoid having a N95 as well as an HTC ...
3.2-megapixel camera and video call camera
There are two cameras. The main camera is 3.2 megapixel and includes Touch auto focus. A picture can be shared with friends or family, as a picture message or e-mail, or using any available transfer method, such as Bluetooth™. There is also a QCIF camera, for video calls, located on the front.
Photo light
When lighting conditions are poor, pictures can be enhanced by turning on the Photo light.
Video capture
The camera also records video and which are stored in the phone or on a memory card. A video clip can be shared with friends or family as a picture message or e-mail, or using any available transfer method, such as Bluetooth™. The phone supports VGA size video recording at up to 30 frames per second.
•MPEG-4: 30fps at VGA*
•H.263: 30fps at VGA*
•H.264: 15fps at VGA*
Can forward on to people if they want it ....
I do struggle that so many people are worried about WVGA. The G900 ran all the s/w I have without issues including Softmaker Office, CPL6, PI, FM, Pie+ etc ... WVGA is real extra screen estate rather than just VGA prettiness.
I know only time will tell, but this has to be leagues ahead of the Pro.
It is only the price that scares me ... and the fact that there are still performance issues with video at 30fps .... which as you can see from the above is a biggie for me.
The only daft thing missing I can see is the TV-Out ...
downloadtest82 said:
How does this accelerometer function work anyway?
Click to expand...
Click to collapse
These accelerometers actually measure the Earth's gravity also. It constantly measures the 1g with which the Earth is pulling the phone. A 3-axis accelerometer gives you the projection of the gravity vector on each axis (x, y, z). Assuming that the phone is only rotating (and not translating), it is easy to find to where the phone is facing... for example, if the x and y acceleration is ~0 and z is ~1, then the phone is facing up, like leaving it on a table top. If x=1, y=0, z=0 => phone in landscape. If x=0, y=1, z=0 => phone in portait mode.
When the phone is being translated (moving, that is) in a non-constant manner, a "dynamic" acceleration vector is added to the 1g Earth's vector. In that case, calculating the phone's position/rotation becomes more tricky and more erroneous...
downloadtest82 said:
i.e. "free fall" --> acceleration of 9.81m/s^2 = 1g
Click to expand...
Click to collapse
Actually, in free-fall, the acceleration is reported as zero.
Even ipod nanos come with accelerometers now. Don't sit well with me if the xperia doesn't.
Well, even the C905 and G705 have accelerometers, so why couldn't SE put one into their flagship
Pinguino1 said:
...the accelerometer word in mobile phones is a missnomer because I'm sure they have something simpler that I would call it "Balancerometer"
I believe it's just 2 or 3 tubular circles perpendicular to each other. These tiny tubes are filled with some kind of liquid The reading of the position of these liquid is enough to know the position of the device ex: Vertical, horizontal, diagonal at any angle of mesurement...
Click to expand...
Click to collapse
Years ago I used to think alot of debives measured that way, at one time it may have been like that but not now.
http://en.wikipedia.org/wiki/Piezoelectric_accelerometer
I have an RC Helicopter and a strong interest in electronics...so yeah, I just happen to know random stuff like this, lol.
They manufacture these in bulk as chips often...some even having 3+ (rotation) axi on the same chip.
Even at retail you can get the raw high-end chips for a couple bucks...imagine how much they cost in bulk.
hypest said:
Actually, in free-fall, the acceleration is reported as zero.
Click to expand...
Click to collapse
i suggest you to retake physics...
currently the accelerometer is just for user interface for phones, not too many uses
Ok so people have been confused over the tech thats behind the Iphone/G1 capacitive dual touch screen, and all WinMo phones resisitive screens. So i thought i would do the great job of researching the tech behind both methods. 10 minutes later i came across this info on how both methods work, as well as a more expensive and even better method using acoustic mumbo jumbo. So for all you out there that are too lazy to do the diggin, heres the info that once and for all puts the rumors to bed about "...i heard its dual touch capable from so and so website..."
PLEASE READ>>>
The resistive system consists of a normal glass panel that is covered with a conductive and a resistive metallic layer. These two layers are held apart by spacers, and a scratch-resistant layer is placed on top of the whole setup. An electrical current runs through the two layers while the monitor is operational. When a user touches the screen, the two layers make contact in that exact spot. The change in the electrical field is noted and the coordinates of the point of contact are calculated by the computer. Once the coordinates are known, a special driver translates the touch into something that the operating system can understand, much as a computer mouse driver translates a mouse's movements into a click or a drag.
In the capacitive system, a layer that stores electrical charge is placed on the glass panel of the monitor. When a user touches the monitor with his or her finger, some of the charge is transferred to the user, so the charge on the capacitive layer decreases. This decrease is measured in circuits located at each corner of the monitor. The computer calculates, from the relative differences in charge at each corner, exactly where the touch event took place and then relays that information to the touch-screen driver software. One advantage that the capacitive system has over the resistive system is that it transmits almost 90 percent of the light from the monitor, whereas the resistive system only transmits about 75 percent. This gives the capacitive system a much clearer picture than the resistive system.
On the monitor of a surface acoustic wave system, two transducers (one receiving and one sending) are placed along the x and y axes of the monitor's glass plate. Also placed on the glass are reflectors -- they reflect an electrical signal sent from one transducer to the other. The receiving transducer is able to tell if the wave has been disturbed by a touch event at any instant, and can locate it accordingly. The wave setup has no metallic layers on the screen, allowing for 100-percent light throughput and perfect image clarity. This makes the surface acoustic wave system best for displaying detailed graphics (both other systems have significant degradation in clarity).
Another area in which the systems differ is in which stimuli will register as a touch event. A resistive system registers a touch as long as the two layers make contact, which means that it doesn't matter if you touch it with your finger or a rubber ball. A capacitive system, on the other hand, must have a conductive input, usually your finger, in order to register a touch. The surface acoustic wave system works much like the resistive system, allowing a touch with almost any object -- except hard and small objects like a pen tip.
As far as price, the resistive system is the cheapest; its clarity is the lowest of the three, and its layers can be damaged by sharp objects. The surface acoustic wave setup is usually the most expensive.
How Stuff Works people, its a great website. heres a picture i made to show you how the tech works, or at least how it appears to me.
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Very informative, thanks.
cool info, thanks for your effort.
but does this mean we may be able to improve drivers for a multi touch on our h/d or on other resisitive screens?
This whole lack-of-multi-touch-on-the-HD thing got me thinking. One problem is obviously the gaming side of things, where you can't push two virtual buttons at once to go at a diagonal say.
If you open up an SMS and use the Transcriber option, then push at two points on the screen, there is a line drawn that stops mid-way between the two pushed points.
Would it not be possible therefore, for a cleverer person than I, to program a virtual D-Pad that could work out when two buttons were pushed simply by triangulating the position of the virtual cursor?
Does that make sense?
That's an interesting point, Major.
Try this also, in the notes app - turn it to drawing mode. Then hold one finger on the screen in one position, and then tap the screen or drag around the screen with your other finger. You see how the touchscreen makes lines that fan out between the two points of contact.
i believe that it may be possible to somehow utilize the fact that something does happen when pushing in on two points of a resistive screen.
the real problem with it is that when you push on two seperate points, the screen makes an indentation that spans across the area between the two. the layer you are pushing on is simply not elastic enough to register two smaller seperate points or indents. its just read as one big indent on the layer between the two points of pressure. this is why the the screen only reads a point between the two. the sensor is just picking up one giant blob that centers at the mid point between your two fingers. this wouldnt really help much because the farther apart your fingers are the more random the point location becomes---this is because the thin layer will be contacting the layer below at multiple random spots between your two fingers. idk. it seems like it wasnt meant for multi touch. and a driver would need to have a more precise input than that.
Ahh, but consider a simple d-pad arrangement, with 4 direction buttons and maybe 2 action buttons (à la SNES or similar?). Diagonals would be easy enough with the point of contact appearing between the 2 buttons pushed. A move-and-fire combo could be detected with clever placement of the virtual action buttons giving the device a good clear area of detection.
If I get time today, I'll try to draw a simple graphic. A picture speaks a thousand words and all that.
Edit: OK, excuse my laughable drawing, but you get the idea. With better placement, the buttons could be made quite in-sensitive to where the fingers/thumbs are pushing on them.
My thoughts on the matter.
I think it would do emulator or even virtual d pad developers well to add this option into their d pad. When you press on two points the screen reads in between right? So if you're playing mario and you're trying to run and jump over a hole, just have a setting that allows right button to continue if suddenly the pointer reads in the middle of the screen. In otherwords, it would make no sense for a nintendo player to suddenly press the middle of the screen, so the d pad would read that as a whichever butten first pressed, plus button now being pressed.
If it reads exactly between both points, then the software should be able to guess which button you're pressing by calculating which buttons are exactly in line with eachother. There will be a beginning reference set by the first point pressed, so it is only a matter of auto executing o---^---0. I hope this idea makes some sense to someone other than me.
Just think of Orion's belt and it's symetry to get the right idea of what I'm talking about.
Caid.
Just a bit more clarity, if the d pad developers set up a reference of center screen points, the could technically program their pads to be multitouch souley off the basics that each two buttons pressed together would have a center point at an exact or near exact point in between the left and right side of the d pad. This wouldn't work for diagnal, but for any direction plus ABXYLR there would be a center point between each of them, a place in between them that the phone would register the touch.
Is this exploitable?
Sorry for constantly editing, but ideas keep crystalizing.
Beyond the first idea, to register an A+b, have slide vs tap settings on the d pad. That means, if I slide from a to b, the d pad will hold a and activate b as opposed to just switching between the two. Once again, this should technically be possible with the first idea as the middle reference point should also read a shift. In fact, if you're pressing on both sides of the screen at once (d pad and abxy) then all the actually pressing action would be happening in the center of the screen or rather between both pads.
tazbo28 said:
the real problem with it is that when you push on two seperate points, the screen makes an indentation that spans across the area between the two. the layer you are pushing on is simply not elastic enough to register two smaller seperate points or indents.
Click to expand...
Click to collapse
I seriously doubt that it's technically any more difficult than calculating the two touch positions on a capacitive digitizer (keeping in mind that in reality "multi" means "dual").
it's actually hysterical raisins (historical reasons) that resistive is single touch only - when PDAs were first developed, the designers had to cater for both stylus (very precise) and finger use. Finger use is spread over the fingertip so the designers hard-coded algorithms that would average out the touch coordinates so the middle of the touch events.
The mentality basically went along the line of "why would you want to touch two points on the screen at the same time? Nothing uses that! Can you think of a use for that? No? Ah well, we don't need that then"
This has held until Apple decided to use the more battery draining capacitive method (resistive only uses battery when the two layers touch, capacitive has a constant charge and therefore constant drain) and decided to use multi-touch as a gimmick (and, lets be completely blunt here it IS a gimmick - pinching is NOT easier than running a circle around the point of interest and it's certainly more clumsy than a slider for zooming!) under the pretense of a new and awesome feature for mobiles (it does have practical use in laptop trackpads though)
Resistive technology does support multi-touch, but it's a bigger issue to code the function because the touch events are processed by the touch controller then sent to the operating system as x/y coordinates. The operating system can't do anything about this. To get resistive technology to support multi-touch you'd have to re-code the controllers...
Major_Sarcasm and Caid444, I agree 100%. If I just had the time, given that I can develop applications using .Net Framework, I should be able to replicate this in a simple application. Will try and get back to you... I'll start with a Win XP app, just the concept, and then I will deal with Compact Framework (if it's still called 'Compact'). Making drivers to work in any application is another story, though.
tazbo28 said:
Ok so people have been confused over the tech thats behind the Iphone/G1 capacitive dual touch screen, and all WinMo phones resisitive screens. So i thought i would do the great job of researching the tech behind both methods. 10 minutes later i came across this info on how both methods work, as well as a more expensive and even better method using acoustic mumbo jumbo. So for all you out there that are too lazy to do the diggin, heres the info that once and for all puts the rumors to bed about "...i heard its dual touch capable from so and so website..."
PLEASE READ>>>
The resistive system consists of a normal glass panel that is covered with a conductive and a resistive metallic layer. These two layers are held apart by spacers, and a scratch-resistant layer is placed on top of the whole setup. An electrical current runs through the two layers while the monitor is operational. When a user touches the screen, the two layers make contact in that exact spot. The change in the electrical field is noted and the coordinates of the point of contact are calculated by the computer. Once the coordinates are known, a special driver translates the touch into something that the operating system can understand, much as a computer mouse driver translates a mouse's movements into a click or a drag.
In the capacitive system, a layer that stores electrical charge is placed on the glass panel of the monitor. When a user touches the monitor with his or her finger, some of the charge is transferred to the user, so the charge on the capacitive layer decreases. This decrease is measured in circuits located at each corner of the monitor. The computer calculates, from the relative differences in charge at each corner, exactly where the touch event took place and then relays that information to the touch-screen driver software. One advantage that the capacitive system has over the resistive system is that it transmits almost 90 percent of the light from the monitor, whereas the resistive system only transmits about 75 percent. This gives the capacitive system a much clearer picture than the resistive system.
On the monitor of a surface acoustic wave system, two transducers (one receiving and one sending) are placed along the x and y axes of the monitor's glass plate. Also placed on the glass are reflectors -- they reflect an electrical signal sent from one transducer to the other. The receiving transducer is able to tell if the wave has been disturbed by a touch event at any instant, and can locate it accordingly. The wave setup has no metallic layers on the screen, allowing for 100-percent light throughput and perfect image clarity. This makes the surface acoustic wave system best for displaying detailed graphics (both other systems have significant degradation in clarity).
Another area in which the systems differ is in which stimuli will register as a touch event. A resistive system registers a touch as long as the two layers make contact, which means that it doesn't matter if you touch it with your finger or a rubber ball. A capacitive system, on the other hand, must have a conductive input, usually your finger, in order to register a touch. The surface acoustic wave system works much like the resistive system, allowing a touch with almost any object -- except hard and small objects like a pen tip.
As far as price, the resistive system is the cheapest; its clarity is the lowest of the three, and its layers can be damaged by sharp objects. The surface acoustic wave setup is usually the most expensive.
How Stuff Works people, its a great website. heres a picture i made to show you how the tech works, or at least how it appears to me.
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Thanks tazbo28
Very usefull info here!
Here what the guys working on android have been able to produce with a capacitive screen:
http://gizmodo.com/5097166/android-multitouch-proof-of-concept-aint-pretty-but-it-works
Multi-touch that works "not-so-well-but-at-least-it-does"
tazbo28 said:
the real problem with it is that when you push on two seperate points, the screen makes an indentation that spans across the area between the two. the layer you are pushing on is simply not elastic enough to register two smaller seperate points or indents.
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Your source?
I don't think so...
Just a little comment about the two points creating a crease down the screen. The distance between the metalic layer and the plastic screen is minimal at best, not to mention the material on the top layer is very flexible. I don't think it's likely at all that the screen would have a crease or ridge between the two points, there's just not enough indent to create this scenario.
One more thing, I'm not 100 percent sure, but I get the impression that the space between the two layers isn't actually filled with air but in fact some sort of non conductive fluid or gel. It would help the two laters to retain their space and elasticity from eachother.
But what do I know without poking holes in my screen (and I'm not about to do that.)
Caid.
just got this from wikipedia
Resistive touchscreens are composed of two flexible sheets coated with a resistive material and separated by an air gap or microdots. When contact is made to the surface of the touchscreen, the two sheets are pressed together, registering the precise location of the touch.
For example, during operation of a four-wire touchscreen, a uniform, unidirectional voltage gradient is applied to the first sheet. When the two sheets are pressed together, the second sheet measures the voltage as distance along the first sheet, providing the X coordinate. When this contact coordinate has been acquired, the uniform voltage gradient is applied to the second sheet to ascertain the Y coordinate. This operation occurs instantaneously, registering the exact touch location as contact is made.
Resistive touchscreens typically have high resolution (4096 x 4096 DPI or higher), providing accurate touch control. Because the touchscreen responds to pressure on its surface, contact can be made with a finger or any other pointing device.
the part about "microdots" is true i can see the grid of super tiny dots on my 8125 touch screen
could anyone share any experiences for a good working stylus for the hd2?
this phone is stupendous but alas i have to use it for work and the software we use requires very tiny touches and signature signing.
have tried the ones on e-bay (rubber topped pencil turned upside down)
which is crap...have now tried the htc and dagi ones with the tiny red dot and they are just not cutting it.
has anyone done any homemade experiments or come across a moe "pointy" stylus
toodle pip amigos
I got some, and they were crap...
davidcampbell said:
I got some, and they were crap...
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Unfortunately you are all too correct!
With the glass screen!
Put a protector on it and they work!
I have been using the dagi long slim one and it works ok, I do have a screen protector on though so maybe this helps... makes selecting text and writing Chinese characters much easier (I use my hd2 to study/translate Chinese so being able to use a stylus to do this is pretty great)... its a bit fiddly to start with as you need to learn how to use it properly, but once you get used to it everything is ok...
Most of the styli are crap, I need something with more of a point, but that's probably not possible. Still waiting for some sort of battery powered pen that offers pin point precision, a guy can dream right...
i'll try to put a screen protector on as suggested and try...
my problem is it's no good mastering the dagi myself as i have to get customers signatures and most people simply can't use it...
it deffo needs something more pointy.
i'm sure i read somewhere on the forum about a guy who was filing something to a point till it stopped working???
i'm so frustrated as this is the only phone in 8 years that uses my works software flawlessly...except stylii
I have ordered the official htc stylus 400.
arrives in 2 weeks and i'll post comments.
read a review after ordering that it actually scratches the screen!
I guess i should have waited for the 400/2 version!
look on the bright side, will probably misplace it by the second day anyway
I've tried using my DS stylus but that doesnt work, seems like it was made for bigger objects to come in contact with the screen (ie fingers).
ILLEATYAFACE said:
I've tried using my DS stylus but that doesnt work, seems like it was made for bigger objects to come in contact with the screen (ie fingers).
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It`s not about the size of objects. HD2 has capacitive screen.
"A capacitive touchscreen panel consists of an insulator such as glass, coated with a transparent conductor such as indium tin oxide (ITO).[2][3] As the human body is also a conductor, touching the surface of the screen results in a distortion of the body's electrostatic field, measurable as a change in capacitance. Different technologies may be used to determine the location of the touch. The location can be passed to a computer running a software application which will calculate how the user's touch relates to the computer software."
Wikipedia
thanx for input guys..i least i know about capacitive screens now thanx to kregowski...although i sorta knew.
so if someone could come up with a small pointy thing that gives off some sort of electro staticy stuff...we in..
the search continues
Got the dagi (10 euro from Hong Kong). I am not amused... Touching the screen with the complete tip flat on the screen is annoying to get used to. Often only the side of the tip touches the screen.
When the tip is flat on the screen (which it should) it just does not feel OK. Not "delicate".
Which the screen responsiveness lowered and the tap-reaction time increased (which I did just to be able to get some decent fingertyping results) the dagi does not function adequate. I have to aim more accurate then with my fingers and have to press the dagi on the screen.
Putting the screensettings to default (which I did not try yet) reinstates all the drawbacks in the other functionalities.
On a black background is a white dot, but on a white background it is not visible.
Dead pixel?
Yep. That's what is usually called a "stuck pixel", in opposition to dead pixels which are always black.
it means that it is possible to fix it?
AFAIK, no, it's not possible. But pixels on the HD2 are small, you will probably get used to this. I have a stuck subpixel (not a full pixel, when the screen is all black I have a green dot), and I am unable to notice it unless I look for it very carefully. Forget it and your eyes won't be meeting it more than once a month.
Hey guys check this post out, I think you both might want to read this, very smart guy member facdemol.
http://forum.xda-developers.com/showpost.php?p=12670084&postcount=18
thanks for quoting T-Macgnolia.
yep, as i explained on those 2 posts in that topic one single pixel on hd2 screen's working with something like theese
- 3 subpixels
- each subpixels is made up of a pair of liquid crystal and driving transistor
- each transistor is linked to a processing chip (it organizes the screen into columns and rows, and drive them separately)
- each processing chip (the ones that trigger columns and the ones that trigger lines) are linked to a lvds bridge (that's some sort of protocol used to communicate to the gpu's analog output).
- gpu or other video processing subsystem
How to recognize various hardware failures occuring to the screen:
- white screen (nothing displayed) - this is pretty serious. As i've posted on my other topic, the crystals in the screen are normally transparent. If you apply various electric signals the matrix will actually produce colors by blocking various light wavelengths. If you get a white screen and you have already determined somehow it's not related to software issues, this most probably means faulty lvds bridge or connector (the display connector). Because the lvds is not communicating with column and row processing crystals - nothing is displayed on the screen. Entire matrix is powered off. Another cause can be a faulty GPU or video subsystem. If no video signal is being sent, the matrix will be also powered down. With crystal in their natural state, they will be transparent, thus - white light. Not user fixable, each part must be diagnosed, special equipment required.
- screen working but color lines appearing on the display or permanently there. You may have seen a laptop or tv doing this. The display works but there are some strange lines that are permanently there and either don't change color, or change it in a strange way. This happens when you have a faulty row or column driver. If that chip fails - all mosfet transistors that drive pixels in that region of the display will either stop working or work in an erratic way. Thus you get... a line (vertical or horizontal) on the display. Not user fixable, in 80% cases it requires another display as the faulty chip is in most cases embeded into the display module itself.
- screen works but with strange colors (inverted, red-ish, blue-ish or whatever). The lvds bridge - that feeds video signal to the processing chips on the display, contains a small subsystem called contrast & crominance setting. It's fixed on most displays (although i found some older pda's where this can be fine tuned). Simply put it's a small circuit made up of a negative voltage driving a PNP junction bipolar transistor working in a voltage divider circuit. The divider will actually... well.. divide the voltage across it and these 2 voltage resulted (together summed they give up the original voltage) are required for each corresponding column and row controller chip to know how to bias the pixel matrix. If you bias the matrix to hard (larger voltages makes the transistors to switch at smaller imput levels, so they are triggered more easier) the crystals will change transparency level faster, thus you will get a darker screen or strange colors. If in a normal situation you will need 0.3Volts to drive a subpixel to fully block light (on it's specific wavelength) a harder biased matrix will require only 0.2V - for example. However as the voltage varies from 0 to 0.3volts in a normal case of color reproduction by a subpixel, you reduce the maximum range by forcing the corresponding mosfet transistor to do at 0.2volts what is was supposed to do at 0.3volts. The GPU and LVDS bridge will still send signal from 0 to 0.3 but the display's transistors won't display anything different from 0.2 to 0.3 range. Thus you get color alterations. If you find this problem in a display, it means this specific subsystem (contrast/crominance) has either failed or it's drived improperly. Inverted colors means the transistor in the crominance block is actually either dead or has a faulty connection. Instead of driving the display with 0.3 volts it used -0.3 voltage. All hell breaks loose. By no means user fixable. This subsystem is also located on the display module level. Older pda's or smartphones have this thing mounted on the ribbon cable coming out from the LCM itself. Those have a chance to be repaired without changing the display.
- white spots on the display. Most visible on white background. I repeat, spots, not bunch of little points (pixels). Those areas will still display colors, but with some distorsions. I didn't covered these when explaining the lcd display hardware. Well simply put the problem is like this. LCD backlights are made up from small white led's. However, the problem is that a led is a point like light source. Light is more intensive near the led and decreases as you move further. So, if led's were simply placed on the bottom of the screen , the upper part will be darker or the backlight won't be evenly spread. In order to solve this, manufacturers use some sort of polarizing filters in order to deflect light and "move" it more effectively. 2 polarizing filters are used, they are 2 foils containing some veeery small mirror like material that reflects light only when it passes though them at a specific angle. By using 2 filters (horizontal/vertical) and other specific materials, the backlight assembly can spread the light produced by 3-4 small leds on the whole screen surface. The foils are placed together in contact with each other and their final role is to direct the light straight into the display's matrix in order to fall vertically over the liquid crystals and through them - to you. IF however the backlight assembly is damaged due to mechanic shocks for example, those thin foils can bend or change their original orientation. Because of that, light won't be diverted vertically, won't pass though the crystals at the correct angle and thus.. you'll see spots on the screen. Another way for this problem to occur is water or dirt getting into the backlight assembly. Both can affect either the orientation of the polarizing filters or simply leave dirt on them. Either by mechanic shock or dirt, this problem can appear. I have a samsung omnia with this problem, i heard about 1/4 of them have it due to poor design of the phone's case against mechanic shocks.
Not user serviceable. I disassembled laptop screens in order to repair them or to change polarizing filters but it's a very stressful job. The smaller the screen the harder to repair it. I don't think it's even possible to find replacement backlight modules for phone screens. You either have to live with the problem or change the display.
- bad pixels. If you see a color dot (they are either green, red, blue or combinations of these) you have either one or couple of "dead pixels/subpixels". If you see a white/black dot - you have a full dead pixel. Well, what's happening there?
- single color dot. - damaged subpixel. This is basically a mosfet transistor that's blocked into conductive state and can't switch off. The pixel is working (not dead) but can't be turned off or assume variations in displayed color.
- single black dot - if all 3 subpixels that form a pixel are having the problem above, you get a black dot.
- single white dot - 3 dead subpixels. No power is getting in. Either 3 transistors commanding 3 subpixels (one pixel) are incapable of switching on or their 3 crystals are incapable of changing their state (rare scenario). In most cases, we get this from transistor failure.
- bunch of color dots - if they are located in close distance to each other, suspect a mechanical shock to the matrix. If they form a geometrical shape, suspect logical damage (transistors improperly driven or simply not powered on at all). If the pixels form a line across the screen - well, you diagnosed the problem incorrectly, those aren't your usual "dead" pixels, see above - you may have a row/column controller chip problem.
Dead pixel - user fixable? In some rare situations (i mean .. pretty rare) varying the screen content very fast is a way of attempting to unblock a locked transistor. In some lucky cases this will solve the problem. I had some success some time ago, in some cases it worked after couple of hours of displaying those rapid moving/alternating colors, in other cases it worked but the problem pixel got stuck again after some couple of weeks, in most cases it never worked at all. Worth a shot, couldn't harm to try. There are programs that do this job for you, something like "dead pixel fixer" or do a search on either marketplace or google for an app for your OS.
These are the most common problems with LCD displays (all sizes). Of course there are the "exotics" but most people will never see one. As you can see, there is not much to do or repair with smaller phone screens. No replacement subcomponents, too small...
TV screens for example can be disassembled and various components replaced or repaired individually. Hope it helps or gives you something to read in the morning when drinking your coffee.
Hey facdemol thanksfor that very informative post. As I have said before you are the man.