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Mcrophone,Speaker | Cypress Semiconductor

Mcrophone,Speaker

Summary: 16 Replies, Latest post by danaaknight on 26 Jul 2012 05:36 AM PDT
Verified Answers: 0
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user_201261815's picture
User
43 posts

Hello Sir/Mam,

                          I am using CY8CKIT-001,i want to connect microphone and speaker to the PSoC3 ,may i know what should be the specifications of Speaker and microphone required to connect to PSoC 3.

hli
user_78878863's picture
User
2759 posts

Can you tell us what you want to with that? Otherwise it is just looking into a crystal ball :)

For the microphone, a pre-amplifier might be needed (e.g. if you use a pure electret microphone capsule). For the speaker - you cannot source more than 25mA of current. So the speaker nees to have a high enough impedance if you want to connect it directly (130 ohms when using 3.3V).

user_201261815's picture
User
43 posts

Here i want to connect the microphone to PSoC ,digitize the microphone output and store the values in memory of PSoC and i should hear  the sound signal using  speaker ,where speaker input is the output of the DAC(PSoC peripheral).

so i just want to know the specifications of Microphone and speaker to get better result using PSoC..

user_14586677's picture
User
7648 posts

There is no simple answer here. The questions that have to be answered -

 

1) What power level do you want out of the speaker ?

2) The above drives the technology to some extent ?

3) Hi fidelity, or phone grade, or something in between ? What is the frequency response you

want out of Mic and Speaker ?

4) External amps or strictly onboard solutions ? 1) has a great impact.

5) Speaker or ear buds, affects needed power.

6) Are you doing speech recognition ? If so fidlelity, at the very least repeatability

very salient discussion here.

 

Hopefully someone can give you a recomendation, but until you decide

whats is acceptable, specs of some sort, you are treading water so's to speak.

 

I am not being disrespectful when I say you have asked what car should I

buy, and given the forum no other requirements. Does it have to have 4 wheels,

wings, engine........

 

Regards, Dana.

 

hli
user_78878863's picture
User
2759 posts

If you want to just play around:

  • try to get a microphone which delivers line level (1V or so) - this saves you the need for an amplifier, and you get less noise (you can use an PSoC-internal amp, but the noise is higher then)
  • use simple head-phones as speakers. Measure their impedance, and maybe add some resistors to get at least 130 ohms (200 would be better)
user_14586677's picture
User
7648 posts

Just a thought, if you first do the homework, that is eliminate poor quality mics and speakers,

get good quality parts, do whatever it takes to do interface, you have eliminated, temporarily

the transducers from the evaluation. By doing this you can see what PSOC and various sample

rates/compression will be required. Then you can work on "dumbing" down the transducers,

mic and speakers, cost and quality, until you have reached unacceptable performance.

 

Regards, Dana.

H L
user_460349's picture
User
1362 posts

If you just want to test, you can use the speaker as the microphone, so you don't need a buy a microphone. Test the hardware first(ie build hardware to amplifier the signal from the MIC, and feed the output to another speaker (with series resistor). one you get good level. then use a pure sine wave as the souce for recording into the PSOC memeory and play back the tone. Once that is done. Then try to use the MIC to test. Do it one step a time

user_201337982's picture
User
127 posts

basically microphone take maximum 1v signal.so use a buffer circuit to develop your hardware

user_201337982's picture
User
127 posts

Zelscope is a Windows software that converts your PC into a dual-trace storage oscilloscope and spectrum analyzer.

 

reference website:

www.zelscope.com

 

u have to use this circuit to couple microphone

 

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user_14586677's picture
User
7648 posts

Microphone interface circuits are specific to the technology being used for

the mic itself. Generally their datasheets have an interface circuit targeted towards

the mic element being used, and make compromises in the freq response plot of the

mic to "flatten" it or remove objectionable peaking.

 

One size does not filt all.

 

Regards, Dana.

hli
user_78878863's picture
User
2759 posts

Don't use this circuit to connect your microphone to the PSoC! I creates up to 12V on its output, which will destroy your PSoC.

You need to get "line level" - which is about 1V (this is what gets delivered by a typical cinch output). Use either a microphone with integrated preamplifier, or get one suitable for your microphone.

If you really want to save money, and are willing to experiment: use a headphone as microphone. Connect it to a PGA on the PSoC with the highest amplification. This might be enough for basic experiments (I did not try it).

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