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DaKing |
2009-09-15
, 15:42
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Joined on Sep 2009
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#271
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i have a question about the windows live messenger application will it be released just like the one in the windows mobiles ? or how will the chat messenger of hotmail ( msn ) be ?? 
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2009-09-15
, 17:01
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Posts: 107 |
Thanked: 94 times |
Joined on Dec 2007
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#272
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Originally Posted by iKneaDough
No, not necessarily g-force. Any acceleration will be measure. These devices will work anywhere even deep space with no gravity. They work because certain crystals can generate small electrical current if the crystalline structure inside are stressed (i.e. deformed). That is if you grab a crystal and squeeze it in you fingers it will generate an electrical current.
@BadMojoUT : Thanks for your reply! very informative.
Do you mean something like g-force ?
Now for the way it works in an accelerometer, think back you basic physics. More specify Newton's 1st law. (paraphrased) An object at rest tends to stays at rest...unless acted upon an outside force. The crystal is mounted in an accelerometer normally at rest. Now when the device it's mounted in moves, a certain amount of force is exerted on the crystal. The crystal wants to stay still, but it's mounting points are pressing against the crystal which will deform the structure of the crystal. Just like squeezing the crystal in your fingers.
And the key is that the crystals inside the accelerometer is that they only measure movement along a certain direction (aka vector in science speak). So you mount 2 (or 3) crystals so you can measure the up/down and left/right movements.
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2009-09-15
, 17:19
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Posts: 271 |
Thanked: 220 times |
Joined on Sep 2009
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#273
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Originally Posted by sljonson
The term "g-force" is a colloquialism that is generally used to describe acceleration forces felt from an observer's frame of reference...not just the "g" (9.81 m/s^2 vector pointed at earth's center) imposed by the earth's gravity.
No, not necessarily g-force. Any acceleration will be measure. These devices will work anywhere even deep space with no gravity. They work because certain crystals can generate small electrical current if the crystalline structure inside are stressed (i.e. deformed). That is if you grab a crystal and squeeze it in you fingers it will generate an electrical current.
Now for the way it works in an accelerometer, think back you basic physics. More specify Newton's 1st law. (paraphrased) An object at rest tends to stays at rest...unless acted upon an outside force. The crystal is mounted in an accelerometer normally at rest. Now when the device it's mounted in moves, a certain amount of force is exerted on the crystal. The crystal wants to stay still, but it's mounting points are pressing against the crystal which will deform the structure of the crystal. Just like squeezing the crystal in your fingers.
And the key is that the crystals inside the accelerometer is that they only measure movement along a certain direction (aka vector in science speak). So you mount 2 (or 3) crystals so you can measure the up/down and left/right movements.
Also, the accelerometers used in applications like this utilize changes in the resistive or capacitive properties, not the measurement of a current (voltage). The resistance and capcitance changes are steady-state depending on the strain (hence stress, hence force, hence acceleration) similar to old-school strain gauges.
Voltage creation by piezoelectric devices is dependent on *rate of change* and is far less useful in this use case since you not only have to measure instantaneous voltage but have to keep a history to make that measurement useful. Contrast with a pizeoresistive or capacitive element where the instantaneous measurement of the resistance/capacitance corresponds directly to the acceleration at that very moment without need to consider the history of change to make that calculation.
Perhaps a pedantic correction..but it is worth noting IMHO.
Last edited by texaslabrat; 2009-09-15 at 22:05.
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2009-09-15
, 17:20
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Posts: 835 |
Thanked: 772 times |
Joined on Oct 2007
@ Finland
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#274
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Originally Posted by timsamoff
Perhaps, with something like this and workload of image prosessing?
All true. Of course, with a camera, one might be able to calibrate a device by telling it which directions were north/south/east/west...maybe?
Tim
Navi Machine
Simple compass application for 5800. There’s no built-in compass in 5800 so you have to point your phone towards the sun and the red N shows you where north is.
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2009-09-15
, 20:51
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Posts: 267 |
Thanked: 128 times |
Joined on Sep 2009
@ Somerville MA - USA
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#275
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Does the N900 support OTA software updates?
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2009-09-15
, 20:54
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Posts: 2,121 |
Thanked: 1,540 times |
Joined on Mar 2008
@ Oxford, UK
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#276
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Originally Posted by matthewcc
Yes it does.
Does the N900 support OTA software updates?
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2009-09-15
, 22:43
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Posts: 1,258 |
Thanked: 672 times |
Joined on Mar 2009
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#277
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well I guess if Carmack gave up on using ins in his space rocket, i should give up making a faster speedometer 
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2009-09-16
, 18:18
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Posts: 635 |
Thanked: 282 times |
Joined on Sep 2009
@ Black Mesa Research Facility
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#278
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i want to ask about the memory (storage space)...uptil now i have no clue how it is divided...the device has 32GB of space...and 768MB from it is used for swap RAM...right? so, the rest (about 30GB) is free and i can put there anything i want, right? Coz i read somewhere it has actually just 65Mb of space...so, how is it really?
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2009-09-16
, 18:34
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Posts: 5,478 |
Thanked: 5,222 times |
Joined on Jan 2006
@ St. Petersburg, FL
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#279
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Originally Posted by Jack6428
See my earlier post on the subject.
i want to ask about the memory (storage space)...uptil now i have no clue how it is divided...the device has 32GB of space...and 768MB from it is used for swap RAM...right? so, the rest (about 30GB) is free and i can put there anything i want, right? Coz i read somewhere it has actually just 65Mb of space...so, how is it really?
Originally Posted by GeneralAntilles
The 1GB mounted on /opt provides a place for additional application storage, so ignore that 65MB number as it doesn't have anything to do with the final product.
The current layout as I understand it (all pre-release specifications are subject to change, of course):
32GB eMMC256MB NAND
- 768MB of swap
- "Over" 1GB of ext3 mounted on /opt
- Remaining space mounted on /home/user/$MYDOCS as FAT32
MicroSD
- Bootloader
- Kernel
- rootfs
- FAT32 partition
__________________
Ryan Abel
Ryan Abel
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2009-09-16
, 18:43
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Posts: 635 |
Thanked: 282 times |
Joined on Sep 2009
@ Black Mesa Research Facility
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#280
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Originally Posted by GeneralAntilles
so in other words...i will have just 1gb of space only for applications and the rest will be for movies, music, pictures, etc. ? not that 1gb would be small, but let's say i install alot of games...the space will be filled easily...i understand correctly, right? can this be somehow changed? and if i format my device, can i choose which part it deletes or will it delete everything?
See my earlier post on the subject.
The 1GB mounted on /opt provides a place for additional application storage, so ignore that 65MB number as it doesn't have anything to do with the final product.