Comments on: Cheap Sound Sensor for AVR

By: Alan

Alan — Tue, 21 Aug 2007 23:05:22 +0000

Nice job, it seems to follow the music quite well!

By: Philippe

Philippe — Tue, 23 Oct 2007 13:23:32 +0000

30 years ago I built something like that… it was all analog and involved lighting a 115v bulb.
Funny thing is that it probably cost more to build at the time.

By: Justin

Justin — Mon, 12 Nov 2007 04:29:07 +0000

Thank you so much for the link to the schematic for the mic and LED, I have made a 4X4X4 RGB LED cube that is going to go to sound but I had no way to read it, I just got the parts and it works great. I have to code the LEDs though. Thanks a lot,
Justin

By: alaa

alaa — Thu, 10 Jan 2008 16:30:17 +0000

I need small sound sensor can sense high noise, working by battery, working in open area(high limitation). the output of this sensor is a sound also as handset or small speaker without display screen or indication lamp.
for example: i use hanset in my ears to say to me how the noise level is.

By: odiernod

odiernod — Thu, 24 Jan 2008 17:09:03 +0000

I put this circuit together too and am happy to say that it works just fine, however, “how” does it work? What is the capacitor for? Why is there a resistor in parallel with the base and collector of the transistor? I am used to using transistors in switching applications, however I am interested in why this circuit can do what it does.

By: Alex

Alex — Thu, 24 Jan 2008 19:08:30 +0000

Hi odiernod,
cool that it worked for you!
The capacitor is used to decouple the mic from the transistor. It is used to transmit only the changes in voltage. I am quite sure that the resistor is used to adjust the amplification, but my knowledge in analog circuits is quite limited.

You can also take a look at
http://tinkerlog.com/2007/10/22/diy-tengu-on-a-breadboard/ for a more integrated amplifier.
Cheers,
Alex

By: odiernod

odiernod — Fri, 25 Jan 2008 05:54:15 +0000

I made a colorful lamp out of my sound sensor circuit. No singing faces or anything, but it still looks cool. I’ll post a vid sometime next week or so.

Dom

By: Azda

Azda — Sat, 26 Jan 2008 16:30:08 +0000

hi, i am interested in building this for a school project and i am wondering if this simple circuit will work as it is on its own?

By: Alex

Alex — Sat, 26 Jan 2008 19:00:11 +0000

Hi Azda,
what do you mean by “work as it is on its own”?
It can be powered by batteries, then it will work on its own.
If you mean, if it could work without the microcontroller, yes, I think it would work. You have to attach another transistor to the collector of the first one and use it as a switch to control the LED. I haven’t tested that, but it could work.
Cheers,
Alex

By: Azda

Azda — Sat, 26 Jan 2008 20:09:20 +0000

thanks for the help alex

By: Azda

Azda — Mon, 28 Jan 2008 15:56:19 +0000

would a MIC1 work with this circuit, and could you possibly post/send images of this circuit bread boared on its own- as on the top image without the microcontroller using a battery.

By: Michael H

Michael H — Tue, 18 Mar 2008 16:16:44 +0000

Alex,
I know this is a little off topic, but I’m not finding answers elsewhere. Can you help me figure out how I could use a setup like this with a 12V neon car light? (4 ft, and I think probably 2.5 amps?) I know this is possible, I just am unsure of what to change.

Thanks for the off topic help.

By: Alex

Alex — Tue, 18 Mar 2008 22:32:11 +0000

Hi Michael,
hmm, not sure about a 12V setup. You will need really powerful transistor to switch 2.5 amps at 12V. I am not into analog electronics, more microcontrollers. But I am sure you wont need the microcontroller for your purpose.
Cheers,
Alex

By: karim

karim — Sun, 23 Mar 2008 07:33:37 +0000

is this circuit can be used to detect alarms without any false indications

By: Alex

Alex — Sun, 23 Mar 2008 07:43:24 +0000

Hi karim,
yes, I think it can be used as sensor for an alarm.
Without any false indications? That depends on your environment.
Cheers,
Alex

By: karim

karim — Sun, 23 Mar 2008 07:56:57 +0000

Thank you very much

i’m really amazed of your fast response

By: BIGBUG

BIGBUG — Sun, 20 Apr 2008 22:02:39 +0000

THANK YOU! This little circuit, with a few minor changes, is just what I was looking for to add bidirectional hearing to my oobug robot. Was looking for something for weeks.

Ted
Savage Innovations
www.oobug.com

By: Alex

Alex — Sun, 20 Apr 2008 23:28:39 +0000

Ted, great to hear that. I am waiting to see the final result.

By: BIGBUG

BIGBUG — Mon, 21 Apr 2008 03:29:34 +0000

Alex,

Could you share the part number for the electret you used in this project?

Have you done any experimenting with the sensitivity of the circuit?

Ted

By: Alex

Alex — Mon, 21 Apr 2008 06:42:18 +0000

Ted,

here is the link for the mic http://www.reichelt.de/?;ACTION=3;LA=4;GROUP=IA2;GROUPID=3604;ARTICLE=11357;
The id is “MCE 100″.

No, I haven’t done anything with the sensitivity.

Cheers,
Alex

By: Reece

Reece — Tue, 10 Jun 2008 15:42:52 +0000

Wait a minute…In the instructions it says ‘electret microphone’, but in the schematics there are only TWO connections to the microphone shown. Is it an electret or a condenser mic? I’m confused…

By: Alex

Alex — Tue, 10 Jun 2008 17:57:31 +0000

Hi Reece,
following Wikipedia http://en.wikipedia.org/wiki/Electret_microphone it is an electret microphone which is a subtype of a condenser microphone. The one that I used has only two connections.
Cheers,
Alex

By: Reece

Reece — Thu, 26 Jun 2008 03:47:57 +0000

Ok. So I THINK I found the right microphone element in my box of goodies (old circuit boards from random stuff). I got it from an old cordless phone. I built the circuit for a project I’m doing. I haven’t tested it yet, though…

Here is a pic of the completed circuit:

http://www.flickr.com/photos/7507189@N04/2612530416/

By: Reece

Reece — Thu, 26 Jun 2008 15:01:51 +0000

Yup. It works great. The butter zone trigger value is ~150 from the ADC. Great circuit; it’s so simple and I didn’t even need to make a complex op-amp one with all those capacitors and resistors. Great for a simple electronic ‘ear’ that can recognize simple handclaps. Thanks for the simple design!

By: Alex

Alex — Thu, 26 Jun 2008 19:35:22 +0000

Great to hear that it works.
Kudos for the design goes to Andrew, who posted the design on Reconn’s world.
http://www.reconnsworld.com/forum/read.php?9,10