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- - Decibel Meter ? (https://talk.maemo.org/showthread.php?t=47918)

Re: Decibel Meter ?

Quote:

Originally Posted by mr id (Post 877815)

sources are the various 'sound' sources your device can see. "source.hw1" should be a Bluetooth headset microphone if connected, I suspect you don't have one paired and that's why the application freezes.

In reality, if you are only interested in measuring 'environmental' sound you probably don't want to change from the default setting.

thanks for the quick reply!

Yhat must be it, at the moment no bluetooth decices are connected.
Maybe it is possible to rename the source names to easy understanding names, such as "source.hw1" could be "bluetooth input"

Re: Decibel Meter ?

With the few changes suggested the application would be perfect.

I love the look.

Re: Decibel Meter ?

...Amazed to see an actual application running not even 3 pages after the request! Keep up the good work! I am not just a fan of N900, also a fan of this community :rolleyes:

Re: Decibel Meter ?

Just uploaded version 0.3.0 to extras-devel.
In this version the text for the source selection was changed to give a more meaningful representation of what is meant.
Furthermore, the icon should now be properly installed (actually already as of version 0.2.4-1).

I'd like to promote this version to extras-testing if you don't find any serious issues.
Your feedback is highly appreciated. :)

Re: Decibel Meter ?

just updated to last version.

great work sofar!!!
1 request is portrait mode.
2 sugesstion: name now is vumeter, but it is a decibel meter, why not calling it dB meter???
3 center the source text in the middle of the button,now it is alligment to the left side.

i love the application,great work in a few days!!!

Re: Decibel Meter ?

I think i found a bug, it seems to pic up audio emitted by the system (programs and OS), even if you turn the volume all the way down, it doesn't matter which "device" you select

edit: or perhaps its only with the FM radio?

Re: Decibel Meter ?

nice work!

it would be handy if you could set a threshold value and execute a command or for example trigger the camera shutter

also it would be nice if you you could dump the dB values in a file with a time stamp.

Re: Decibel Meter ?

Why when there is no noise it keeps showing a value about 30db?

Re: Decibel Meter ?

Define "no noise"

Source of sound Sound pressure Sound pressure level
Sound in air pascal RMS dB re 20 μPa
Very calm room 2×10−4 – 6.32×10−4 Pa 20 – 30 dB

Very good link that was already posted in this thread:
https://secure.wikimedia.org/wikiped...ressure_levels

Re: Decibel Meter ?

Thanks for the feedback so far.
Some comments to the points that had been mentioned:

Quote:

Originally Posted by N900@900MHz

2) meter goes to 110 dB, maybe 130 is beter.

Actually, the highest value I could measure was 106 dB (= 200 on linear scale).
See also comments on measurements etc. below.

Quote:

Originally Posted by N900@900MHz

2 sugesstion: name now is vumeter, but it is a decibel meter, why not calling it dB meter???

For the time being I stay with vumeter for some reasons:
- The project was initially registered with that name and I want to keep all resources in a single place where the resources can be easily found.
- I am not sure at all whether the "dB" scale really provides an accurate Sound Pressure measurement (See also comments on measurements etc. below).

Quote:

Originally Posted by N900@900MHz

3 center the source text in the middle of the button,now it is alligment to the left side.

I tried a centered version (0.3.1) but this broke the hildon style, so I go with the non centered version for now.

Additionally, there may be general issues introduced by the way the sound is picked up.
As coderedcomputing already linked, I also used the table from wikipedia as a very rough reference.
As what I can tell with respect to this reference is that the values measured for, e.g., "a very calm room", "conversation", "a car", and "traffic on a busy roadway" actually are very close to the values listed in the wikipedia article.
Though, of course you know this is no real "hard" scientific reference. ;)

Further, the problem persists that the highest value I could measure was 106 dB (see above).
Here we may have to take limitations introduced by the sound hardware into account.
E.g., may a varying value around 20 - 30 dB (besides the fact that this actually represents a very very quiet, mostly inaudible sound) be caused by the "normal" noise caused by the sound hardware (microphone etc.).
Similarly, the issue that 106 dB is the highest possible measurement could also be due to limitations of the sound equipment.
These conclusions are pure speculation as I don't know the specifications of the N900 microphone and sound processing hardware.
Still, we have to be aware of limitations caused by the recording equipment.

Last but not least:
I think the best way to report bugs and request features would be through the garage project site. ;)
This way those reports will not be lost in some thread on tmo.