I have this voice sensor:


I need to know how bytes pass through soundsensor into arduino and get this bytes and put out in a speaker.

I read on the net a Lib PCM thats converts chars in voices, but how do I extract bytes from sound sensor in analog-in?

  • The board you have, if the same in the image has a D0 and A0, and from powers of deduction the D0 will give you true and false according to a set trigger level. You would also probably look what that library you mention uses as a sensor or the general way people use it and also how it expects signal information from a sensor.
    – RSM
    Feb 3 '16 at 12:35
  • for an example, after coding connect a bulb,and clap then the bulb wile turn on. Oct 4 '20 at 10:29

Oh, the joys of buying something off the Internet with no datasheet, no part number and no clue how to use it. And then expecting somebody else to tell you how it works.

That module looks like a KY-038, made by Keyes. No guarantees, though, because I'm not telepathic.

Bytes don't "pass through the soundsensor". Bytes don't pass anywhere, in fact. That board has an analogue output, A0, which is the amplified audio sensed by the microphone. It swings between 0 and 5 volts, and is 2.5V when no sound is being picked up. The board also has a digital output, D0, which is active-low when the intensity of the sound picked up by the microphone exceeds a thershold. I have no idea what this threshold is or what volume it represents, or if it can be changed.

Have a look at the pages on AnalogRead() for information on how to convert analogue audio to a digital signal.

I don't know what you mean by "a Lib PCM thats converts chars in voices" - 'chars' as in the C-type chars or do you mean literal 'characters from a voice', i.e. speech recognition? I cannot tell if you have misunderstood something or there's an unfortunate translation coincidence which is confusing matters.

  • thanks for this help, now i understand. sorry for something, english not is my natural language.
    – Radagast
    Feb 5 '16 at 21:56
  • I guarantee you speak English better than I can speak any other language, so there is no need to apologise. I was keen to help but I didn't know how. If you have any other questions please ask. Feb 5 '16 at 22:14
  • Thanks man, i undestood that analog reads and then i will use this to put the sound out. I will try soon. But for my project i will have to change arduino to raspberry. I will need a camera module and my uno dont have enough pins and clock power haha, but thanks you a lot.
    – Radagast
    Feb 5 '16 at 22:26

This post was awhile ago, but I wanted to offer some more definitive info for others like myself who were trying to identify it. What you have there is the Keyes KY-037 "high-sensitivity voice sensor" module. Mine came with the Inland Arduino Uno RFID Learning Kit.

Apparently the KY-037 and the KY-038 are the same except the KY-037 has a higher sensitivity microphone. I could not find any specs to quantify what that sensitivity difference is, however. Both have a LM393 voltage comparator on the board. The same Arduino code ought to work for both.

Here are a few helpful links I found, some also showing a bunch of the other Keyes modules and how to use them:


http://brd4.braude.ac.il/~ksamuel/ElIn.31361/Lectures/022-Basic%20Definitions%20and%20Concepts%20Sensors%20and%20Actiators%202013-10-10.pdf (Page/slide 40)


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