Hi Paul I think I will try this one thing. Let me reinstall the tinyos tool set and source tree so that I get the original settings for ADC and Mic details and the compare because it might be some change that I have made that is making it behave in this way. Because I do remember making some changes in MicP based on Atm128adc.h values.
I will let you know if the problem still persists. Thanks Akankshu On Thu, Nov 12, 2009 at 6:01 PM, Paul Johnson <oewyn...@gmail.com> wrote: > Akankshu, > > I have taken a look at the code, but I'm not really able to say what is > significantly different between the two other than the fact that > SoundLocalizer is designed to sample the microphone as fast as possible, so > there are probably some optimizations that Hu Siquan (the author of the > code, his email is inside the code if you need it) made to make it perform > better. You would have to talk to him if you have questions about it as I > have no hands-on experience with any of the mts300 functionality. > > Your problem may be that the MicP implementation is that it has more > overhead and samples the microphone fewer times per second. I have no idea > of the speeds, but if for example, the MicP implementation takes 10 seconds > to collect 1000 samples, you may be missing all of the peaks of the sound > events (clapping, shouting, or whatnot) when you are sampling the ADC, > versus SoundLocalizer which is designed to sample the ADC as fast as > possible. Without access to the hardware, and performing some profiling of > each implementation, i can't say for sure if this is the case. > > Sorry that i couldn't help you more. > > -Paul > > > Akankshu Dhawan wrote: > > Hi Paul > Can you tell me what might be the different between the microphone > implementation in MicrophoneC inside SoundLocalizer Vs the MicP inside > mts300 ? > > > Thanks a lot > Akankshu > > On Thu, Nov 12, 2009 at 4:44 PM, Paul Johnson <oewyn...@gmail.com> wrote: > >> CVS under /tinyos-2.x-contrib/tinyos-programming/ >> >> -Paul >> >> >> Martin Osterloh wrote: >> >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> Hi all, >> >> sorry for interfering this thread. But, where can I find the >> sourcecode to the soundlocalizer demo? >> >> Best, >> Martin >> >> Akankshu Dhawan wrote: >> >> >> Hi Michael and Zainul >> >> Thanks a lot for your response. I am grateful to be hearing from you. >> >> I will look into the corrected mean solution before I suggest some >> hardware changes to my team. >> >> Although, my bigger question was why direct sampling by calling >> getData->dataReady on a free running ADC (this is what is used in >> the SoundLocalizer example in Tinyos-2.x described in the book also) >> responds better ? if I try to do threshold detection of every sample >> using the same interface and direct sampling I get values which are >> very responsive and high rate of sampling. I know I am loosing on >> some precision by sampling at a rate other than the default >> ATM128_ADC_PRESCALE but since I am mainly using it for thresholding >> I think my application can handle it. >> >> Can you tell me some comparison between the microphone setup used by >> the MicP and MicStream compared to the SoundLocalizer direct >> sampling setup ? >> >> Thanks a lot once again >> >> Sincerely >> Akankshu Dhawan >> >> On Thu, Nov 12, 2009 at 1:30 PM, Michael Schippling >> <sc...@santafe.edu <mailto:sc...@santafe.edu> <sc...@santafe.edu>> wrote: >> >> I suspect that the straight averaging thing is not what you want. >> >> I haven't looked at the mic data, but it's sampling an AC >> signal (sound wave pressure alternates between compression >> and rarefaction at the frequency you perceive) and is probably >> biased so a no-pressure signal is pretty much in the middle of >> the ADC range. Averaging that AC signal over a number of high-low >> pressure waves will just give you the middle again. >> >> If that is the case, what you want to do is rectify the signal -- >> half-wave would just chop off the samples below the mid-value, >> full-wave would invert them around the mid-value -- before >> trying to average to get a "loudness". If you are trying >> to get the "Sound Pressure Level" -- how loud the sound is at >> any particular time -- it's called "Envelope Following" in the >> good old days of signal processing. If you know any electronics, >> what you want to build is a diode or diode bridge, to rectify >> the signal, and a capacitor to filter, or average, it to a slowly >> varying DC value. >> >> MS >> >> Akankshu Dhawan wrote: >> >> Hi All >> I am using two mechanisms for high sampling. >> 1. Using MicStreamC and changing the prescalar value inside >> MicP to ATM128_ADC_PRESCALE_32 and the gain value is set to >> 64. I create a buffer of 1000 samples and every time the >> buffer gets full I take the average and print it out. The >> problem is that the microphone does not seem to be >> responding or is not showing me sufficiently precise values. >> The average when I dont make a noise is around 500 ADC.. and >> even if I am clapping shouting (for long durations) it still >> shows me slightly */lower values /like 497 etc. So I am not >> sure why this is so ?* >> >> 2. When I created the low level interfaces on my own using >> the sample SoundLocalizer example in Tinyos programming >> book, I am giving the microphone ADC a free run at the same >> prescale setup (there is a difference of some parameter >> being passed through getData as FALSE in that example which >> is suppose to cater to LEFT_ADJUSTMENT ) but when I compare >> the values that I am getting inside dataReady they respond >> well to sounds. This would work for me but I am just curious >> why the MicStream does not work. This way I would not have >> to recreate all the buffer code. >> >> If anyone can please tell me what setting inside MicSetting >> or MicP have I done wrong that it is not responding. >> >> Thanks a lot. >> >> SIncerely >> Akankshu Dhawan >> >> -- >> First they ignore you, then they laugh at you, then they >> fight you, then you win. >> - Mahatma Gandhi >> >> >> >> >> >> ------------------------------------------------------------------------ >> >> >> _______________________________________________ >> Tinyos-help mailing list >> Tinyos-help@millennium.berkeley.edu >> <mailto:Tinyos-help@millennium.berkeley.edu> >> <Tinyos-help@millennium.berkeley.edu> >> >> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >> >> -- >> First they ignore you, then they laugh at you, then they fight you, >> then you win. >> - Mahatma Gandhi >> >> ---------------------------------------------------------------------- >> >> _______________________________________________ >> Tinyos-help mailing >> listtinyos-h...@millennium.berkeley.eduhttps://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >> >> -----BEGIN PGP SIGNATURE----- >> Version: GnuPG v1.4.9 (GNU/Linux) >> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ >> >> iEYEARECAAYFAkr8e2AACgkQa1gn+vovozNg8ACfaJLQVdQFUlNJWg6GDBsQSqAj >> q+8An38HnQsg1iyeSx8odAGKFG5d3EFj >> =BE0Q >> -----END PGP SIGNATURE----- >> >> _______________________________________________ >> Tinyos-help mailing >> listtinyos-h...@millennium.berkeley.eduhttps://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >> >> > > > -- > First they ignore you, then they laugh at you, then they fight you, then > you win. > - Mahatma Gandhi > > -- First they ignore you, then they laugh at you, then they fight you, then you win. - Mahatma Gandhi
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