Electronics notes/Touch screen notes: Difference between revisions
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====Resistive==== | ====Resistive==== | ||
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Most simpler touch screens are resistive. | Most simpler touch screens are resistive. | ||
For a good time they were the rather cheaper option -- largely though economy of scale. | For a good time they were the rather cheaper option -- largely though economy of scale. | ||
They need force, and may require a stylus to be useful. | They need more force than the later capacitive type, and may require a stylus to be useful. | ||
''Can'' have pretty decent resolution. | ''Can'' have pretty decent resolution, but may not. | ||
Each axis, when touched, will give a particular resistance in a range (usually interfaced with an ADC), so can report only a single touch - touching on multiple places (e.g. resting a palm while drawing) will mis-report. | |||
Each axis, when touched, will give a particular resistance in a range (usually interfaced with an ADC), so can report only a '''single touch''' - touching on multiple places (e.g. resting a palm while drawing) will typically mis-report. | |||
There's 4-wire, 5-wire, 7-wire, 8-wire and more. | There's 4-wire, 5-wire, 7-wire, 8-wire and more. | ||
These relate to different accuracies, and some to variants that won't lose as much accuracy over time{{verfiy}} | These relate to different accuracies, and some to variants that won't lose as much accuracy over time{{verfiy}} | ||
====Capacitive==== | ====Capacitive==== | ||
{{stub}} | {{stub}} | ||
Capacitive sensing can sense | Capacitive sensing can sense various materials nearby, which includes fingers or anything with a conductive tip - from specific styluses to sausages in latex gloves. | ||
Designs usually focus on a specific range of capacitive effect, and will then respond fewer things that aren't fingers and closeby. | |||
Capacitive tricks went from being there in only a few devices (e.g. nineties trackpads) | |||
to increasingly common (in MP3 players, and phone touchscreens) in the late noughties, | |||
to uniquitous in phones and tablets since. | |||
Has a few subtypes -- see [[capacitive sensing]]. | |||
One of them can be multi-touch, and '''multi-touch''' tablets and phones are very usually capacitive. | |||
Capactive touchscreens ''can'' be built in a more robust way than resistive (sensors are under the top glass, not part of the top layer as in resistive). | |||
Capacitive touch can also be faster and more responsive than resistive. | |||
Some of the simpler/cheaper designs are less accurate than resistive, though; some handwriting recognition devices actually stuck with resisitive. | |||
====Optical==== | ====Optical==== | ||
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=Brand-specific notes= | =Brand-specific notes= | ||
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There is no real standard, and there are a handful of touchscreen communication protocols you may find, | |||
though some are likelier than others. | |||
https://wiki.archlinux.org/index.php/touchscreen#Available_X11_drivers | |||
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==Elo notes== | |||
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Latest revision as of 23:06, 21 April 2024
Types
http://en.wikipedia.org/wiki/Touchscreen#Technologies
Resistive
Most simpler touch screens are resistive. For a good time they were the rather cheaper option -- largely though economy of scale.
They need more force than the later capacitive type, and may require a stylus to be useful.
Can have pretty decent resolution, but may not.
Each axis, when touched, will give a particular resistance in a range (usually interfaced with an ADC), so can report only a single touch - touching on multiple places (e.g. resting a palm while drawing) will typically mis-report.
There's 4-wire, 5-wire, 7-wire, 8-wire and more.
These relate to different accuracies, and some to variants that won't lose as much accuracy over timeTemplate:Verfiy
Capacitive
Capacitive sensing can sense various materials nearby, which includes fingers or anything with a conductive tip - from specific styluses to sausages in latex gloves.
Designs usually focus on a specific range of capacitive effect, and will then respond fewer things that aren't fingers and closeby.
Capacitive tricks went from being there in only a few devices (e.g. nineties trackpads)
to increasingly common (in MP3 players, and phone touchscreens) in the late noughties,
to uniquitous in phones and tablets since.
Has a few subtypes -- see capacitive sensing.
One of them can be multi-touch, and multi-touch tablets and phones are very usually capacitive.
Capactive touchscreens can be built in a more robust way than resistive (sensors are under the top glass, not part of the top layer as in resistive).
Capacitive touch can also be faster and more responsive than resistive. Some of the simpler/cheaper designs are less accurate than resistive, though; some handwriting recognition devices actually stuck with resisitive.