Electronic devices can use lots of different methods to detect a person's input on a touch-screen. Most of them use sensors and circuitry to monitor changes in a particular state. Many, including the iPhone, monitor changes in electrical current. Others monitor changes in the reflection of waves. These can be sound waves or beams of near-infrared light. A few systems use transducers to measure changes in vibration caused when your finger hits the screen's surface or cameras to monitor changes in light and shadow.
The basic idea is pretty simple -- when you place your finger or a stylus on the screen, it changes the state that the device is monitoring. In screens that rely on sound or light waves, your finger physically blocks or reflects some of the waves. Capacitive touch-screens use a layer of capacitive material to hold an electrical charge; touching the screen changes the amount of charge at a specific point of contact. In resistive screens, the pressure from your finger causes conductive and resistive layers of circuitry to touch each other, changing the circuits' resistance.
Most of the time, these systems are good at detecting the location of exactly one touch. If you try to touch the screen in several places at once, the results can be erratic. Some screens simply disregard all touches after the first one. Others can detect simultaneous touches, but their software can't calculate the location of each one accurately. There are several reasons for this, including:
To allow people to use touch commands that require multiple fingers, the iPhone uses a new arrangement of existing technology. Its touch-sensitive screen includes a layer of capacitive material, just like many other touch-screens. However, the iPhone's capacitors are arranged according to a coordinate system. Its circuitry can sense changes at each point along the grid. In other words, every point on the grid generates its own signal when touched and relays that signal to the iPhone's processor. This allows the phone to determine the location and movement of simultaneous touches in multiple locations. Because of its reliance on this capacitive material, the iPhone works only if you touch it with your fingertip -- it won't work if you use a stylus or wear non-conductive gloves.
The iPhone's screen detects touch through one of two methods: Mutual capacitance or self capacitance. In mutual capacitance, the capacitive circutry requires two distinct layers of material. One houses driving lines, which carry current, and other houses sensing lines, which detect the current at nodes. Self capacitance uses one layer of individual electrodes connected with capacitance-sensing circuitry. Both of these possible setups send touch data as electrical impulses.
The iPhone's processor and software are central to correctly interpreting input from the touch-screen. The capacitive material sends raw touch-location data to the iPhone's processor. The processor uses software located in the iPhone's memory to interpret the raw data as commands and gestures. Here's what happens:
Tuesday, 26 June 2007
Thursday, 10 May 2007
Friday, 16 March 2007
Derek Punsalan went into a Cingular store to trade in his Sprint BlackBerry 8703e for a Cingular BlackBerry Pearl and came out with a receipt with this printed on the bottom:
Not sure what it means, but Derek thinks it could be a glitch hinting that the iPhone price “may be discounted for longer service agreements.” We’ll find out in June.
Posted by afolarin at 17:36
The fervour generated around the keynote speech at Macworld and the contention with Cisco over the naming rights of the iPhone would appear to have peaked as estimated by the number of searches entered into google (see: google trends graphic below).
Posted by afolarin at 17:08
Steve Jobs iPhone keynote speech at Macworld analysed. It looks like there are some thinks not eluted to by Jobs which are pointed out in this video. Apple iTunes going into Ringtones? Traffic prediction incorporated with google maps?
Posted by afolarin at 17:03
Wednesday, 14 March 2007
Apple have been quiet on this area, too quiet....Jobs didn't expressly mention any gaming applications for the iPhone in the course of his keynote speech, however it's only a matter of time before some form of interactive entertainment is announced for the device.
You might ask why Apple would want to get into this tight market with products like Sony PSP and Nintendo DS dominating this area. However this would be to ignore the capacity of the iPhone to displace it's competitors by the sheer convenience represented by this all-in-one media device.
There are other features, similar in appearance to the PSP with it's large (3.5”) screen, the touch-screen interface also enables interesting control possibilities for the games developer. It doesn't stop there, it may also be a possibility to use the accelerometer to control certain games, sure, Steve Jobs simply uses it switch between portrait and landscape modes, but why this feature shouldn't be used for WarioWare Twisted-style games with tilt-based controls...just a thought?
In respect to distribution, iTunes is already on millions of computers and has trained users to accept making micropayments for downloadable content. Downloading games-on-demand over a cell phone network/internet network will surely represent a great edge for the bored commuter? Wi-Fi is already old news on the Nintendo DS and PSP, but since the iPhone is a cell phone, you could theoretically connect to your cell network and play online even without a Wi-Fi hot spot. The built-in web browser also has the potential to allow for mobile play on thousands of free Flash games as well.
The mobile-phone arm of Electronic Arts (EA games) is reputed to be in discussions with Apple about development of the iPhone as a platform for their software. EA mobile expanded its mobile gaming business through last year's purchase of independent mobile publisher JAMDAT Mobile, later rebranded as EA Mobile.
Mock-up of how the iPhone gaming interface could look...
Tuesday, 13 March 2007
There had been rumours (flying around Dec '06) of a release date as early as the 15th of January 2007, this has lead to some confusion and it is suggested that Steve Jobs himself probably postpone the anticipated release date by several months.
So 4-7 months and counting.....
Sunday, 11 March 2007
Stock chart for the 9th of January 2007, the day the iPhone was released. Compared are, Apple, Research in Motion, and Palm.
MacWorld keynote is was from 12pm - 2pm.
12:15 The Intel transition.
12:20 Paramount movies and the new iTunes ads.
12:25 AppleTV announcement and demo. Ships February 2007.
12:40 The iPhone. Ships June 2007.
12:40 It's an iPhone. It has no keyboard, runs on "OS X", syncs to your home computer OS X data, and has the following hardware features.
12:55 Interaction demo: multi-finger gestures, iPod functionality and cover flow.
1:00 Call-making demo: Conference calls and visual voice mail.
1:15 Content demo: iPhotos and rich text e-mail; surfing with Safari and Widgets.
1:30 Content providers: Google and Yahoo executives.
1:40 Accessories and Price announcement.
1:50 Cingular partnership discussed.
1:55 Wrapping up, thanking employees, mini-Concert.
2:10 The end.
I'm interested to know what the consensus is out there, (please answer my poll on the top-left of the screen).
On one hand the iPhone looks like the true all-in-one e-gadget that has long been promised. However there are still a number of unanswered questions not least regarding the keyboard interface. How effective a will the iPhone's button-less system will work for users who do a lot of thumb-typing? The keyboard is certainly one of the battlegrounds if the iPhone is to compete with incumbents like the Treo and Blackberry.
The other area that was mentioned to me recently is the lack of 3G capabilities and the mobile internet facilities. The iPhone will also be able to connect to the Internet through Cingular's EDGE network however it will not be able to utilize Cingular's 3G/HSDPA network at launch.
The iPhone's mini-Safari will no doubt compress images and code to minimise download overhead however the current NY times shown in the keynote example ~500kb would cost $5 to download! iPhone plans are likely to be unlimited packages - however if you're over the initial $500 outlay to get your hands on an iPhone this is probably a secondary issue.