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‫Welcome to the microphone interface on the basis three development board for this demonstration we have

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‫the microphone breadboard breakout module from her just from out of fruit and we're taking the analog

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‫signal output from the microphone and feeding in into the J x d c module on the basic 3 board.

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‫Now with that microphone module we have to divide down the voltage because it gives us an output from

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‫0 to approximately 3 3.3 volts or whatever Vcc is.

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‫But the X ADC module a basic surfboard can only handle up to a 1 volt signal so we have to provide the

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‫divided down.

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‫And so what we're doing is we're taking and reading this microphone signal and when we see it we take

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‫it and we're sampling it at 40 kilohertz because of the humans can hear up to 20 kilohertz.

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‫And according to the Nyquist theory we want to sample at twice that.

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‫So we sample it.

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‫We take that value and we display it on the ladies.

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‫So I want to put the microphone down and you'll notice as I'm talking you can see the different it light

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‫up and they go as a talk a little bit louder the LDS go a little farther out or make certain noises

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‫you can see that more and more Ltd's light up.

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‫Now if I go and how my slide switch and set it to disable you notice that we just have the two Ltd's

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‫in the very bottom right up and that's because one we don't have as precise a resistors as we need to

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‫get this to be exactly correct we'd have to kind of tweak it but also the output of the microphone.

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‫It has a DC bias to it.

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‫So you take your Vcc and divide it by two.

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‫So at approximately 1.6 5 volts are being fed out of this.

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‫Currently right now when there's no sound whatsoever and then I just kind of gets amplified with our

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‫with our voice.

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‫And so as we talk you can see the different entities will light up and move of enabled again.

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‫And as I talk over the microphone you can kind of just see the different entities.

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‫They light up quickly in a little less and with lots of talk.

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‫The harder I talk to our talk you see different melodies light up a little differently.

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‫And so there is a demonstration of a microphone interface running on the bases three development board.