Active Topics
-
Installing CSSU Stable in year 2024 (0)
to Maemo 5 / Fremantle by teroyk - 16 mins ago -
[ANNOUNCE] CSSU-thumb thread - stable Thumb2 on N900 (2,265)
to Maemo 5 / Fremantle by teroyk - 49 mins ago -
Firefox with Leste (7)
to Maemo 7 / Leste by teroyk - 1 hr, 32 mins ago -
Porting apps to Leste (32)
to Maemo 7 / Leste by Arno_11 - 6 days, 4 hrs ago - more...
|
2009-12-15
, 15:53
|
|
Posts: 36 |
Thanked: 2 times |
Joined on Dec 2009
|
#32
|
Originally Posted by cpscotti
Comming back to the acceleration thing. Assuming that the phone does not rotate, why should be the acceleration constant to zero? I think RDJEHV was right. It is the rate of change of the velocity. If you throw your phone straight into the air, it gets slower and slower, until it reaches its highest point. There the acceleration should be zero, i.e. for a moment the phone is weightless. That is precisely what happens during a parabolic flight http://www.experiencezerog.com/parabolic.cfm
Welll... the accelero picks up acceleration, not velocity. Ideally acceleration is zero through the whole "journey". Since the accelerometer is inside (and fixed to) a heavier body it in fact suffers "accelerations" from within the phone itself (like when it is spinning) but that is very noisy...
Edit:
Nevermind, you are right. The acceleration should be constant to 1G, correct? I think I got confused
ste
Last edited by STE; 2009-12-15 at 15:59.
|
|
2009-12-15
, 16:02
|
|
Posts: 3,617 |
Thanked: 2,412 times |
Joined on Nov 2009
@ Cambridge, UK
|
#33
|
Originally Posted by STE
Umm, no. The acceleration will be constant - 1G. What other force is acting on the phone in mid air? A parabolic flight doesn't actually experience zero-gee, it just feels like it - the plane is actually accelerating downwards at 1G.
Comming back to the acceleration thing. Assuming that the phone does not rotate, why should be the acceleration constant to zero? I think RDJEHV was right. It is the rate of change of the velocity. If you throw your phone straight into the air, it gets slower and slower, until it reaches its highest point. There the acceleration should be zero, i.e. for a moment the phone is weightless. That is precisely what happens during a parabolic flight http://www.experiencezerog.com/parabolic.cfm
|
|
2009-12-15
, 16:13
|
|
Posts: 112 |
Thanked: 122 times |
Joined on Dec 2009
@ London, United Kingdom
|
#34
|
Originally Posted by Rob1n
Well.. you should all try accDisplay since physics are not helping. The reason why the phone's accel. readings are all zero (and not 1g) is because all the phone parts (including the accelerometer's internals) are (de)accelerating equally. Accelerometers measure acceleration differences relating to "free-fall".
Umm, no. The acceleration will be constant - 1G. What other force is acting on the phone in mid air? A parabolic flight doesn't actually experience zero-gee, it just feels like it - the plane is actually accelerating downwards at 1G.
Wikipedia might help
For example, the ISS "feels like" zero G (and indeed a accelerometer there will read 0) only because it's indefinitely falling towards earth: orbiting.
Well.. we could go on explaining and giving lot's of examples but really... wikipedia sometimes help.
I really suggest that you (the ones that are still getting how accelerometers work) install accDisplay (extras-testing). With this tool you can "record" the accelerometer's readings and playback slowly and really see what happens.
__________________
Happy n900 owner!
Check my apps: n900fly, accdisplay and the "desktop command execution" widget!
Happy n900 owner!
Check my apps: n900fly, accdisplay and the "desktop command execution" widget!
|
|
2009-12-15
, 19:27
|
|
Posts: 654 |
Thanked: 664 times |
Joined on Feb 2009
@ Germany
|
#35
|
Maybe those guys will adapt it for a new discipline. Height instead of distance 
 |
|
2009-12-15
, 19:32
|
|
Posts: 1,366 |
Thanked: 1,185 times |
Joined on Jan 2006
|
#36
|
With all this accelerometer action there seems to be a missing feature PORTRAIT MODE
|
|
2009-12-15
, 20:02
|
|
Posts: 308 |
Thanked: 118 times |
Joined on Dec 2009
@ UK Swindon
|
#37
|
sorry am I the only one who thinks its not really appropriate for this type of language on an app???
 |
|
2009-12-15
, 20:07
|
|
Posts: 635 |
Thanked: 282 times |
Joined on Sep 2009
@ Black Mesa Research Facility
|
#38
|
Cool idea. I hope you make it a success. It's funny, i like funny.
I wonder...what if the N900 was shot up into space? Would it come back? And what about the height lol?
Try thinking about making a reverse app - when you drop the phone from a cliff to check how deep it is.
I wonder...what if the N900 was shot up into space? Would it come back? And what about the height lol?
Try thinking about making a reverse app - when you drop the phone from a cliff to check how deep it is.
|
|
2009-12-15
, 23:02
|
|
Posts: 53 |
Thanked: 4 times |
Joined on Jan 2009
|
#40
|
Well, at the top of the flight, the acceleration is zero. If there is a way you can detect this with the accelerometer on the phone, that would be the moment to take the picture.
I don't know how the accelerometers work on the n900, but that's the main idea.
Original Poster, if you are here to make apps for the N900, here is my first idea. Hope you like it.
http://talk.maemo.org/showthread.php...823#post427823
Last edited by Bytales; 2009-12-15 at 23:04.
I don't know how the accelerometers work on the n900, but that's the main idea.
Original Poster, if you are here to make apps for the N900, here is my first idea. Hope you like it.
http://talk.maemo.org/showthread.php...823#post427823
Last edited by Bytales; 2009-12-15 at 23:04.
Now. about measuring the 'hardness' of landing, it is totally plausible! I also had that idea.. but well.. maybe for v.2...
Another things in mind are:
Happy n900 owner!
Check my apps: n900fly, accdisplay and the "desktop command execution" widget!
Last edited by cpscotti; 2009-12-15 at 15:41. Reason: typo