SparkFun Electronics Forum

I'm trying to make a device that measures the level of sound in a room fairly accurately and then lights up LEDs if it reaches a predetermined level.

Help me shop!

So far in my shopping cart I have:

Sparkfun RedBoard Arduino
Sparkfun MEMS Microphone Breakout INMP401
Neopixel 24 LED ring
9v battery holder
Surface mount DPDT switch
Jumper wire set


What else do I need?

Thank you for your time and help!

Googling "diy sound level meter" produces 13,500,000 results.
Just pay little attention to the instructables articles. They can often be of little value - untested crap.

As for your shopping list, add this:
https://www.sparkfun.com/products/12642

You said you want it to be accurate. How are you going to calibrate it?

lyndon wrote: ↑Thu Nov 15, 2018 7:30 pm You said you want it to be accurate. How are you going to calibrate it?

To be more specific, I want it to be *fairly* accurate. Not laboratory-level by any means. I read a post where the person used a dB meter app on their phone to get a baseline and adjusted it from there. Hopefully that will work for me.

DanV wrote: ↑Thu Nov 15, 2018 3:08 pm Googling "diy sound level meter" produces 13,500,000 results.
Just pay little attention to the instructables articles. They can often be of little value - untested crap.

As for your shopping list, add this:
https://www.sparkfun.com/products/12642

Thank you for the advice! Is that in addition to, or replacing the MEMS microphone breakout? If it helps, it will be almost completely enclosed in a plastic casing, I picked the MEMS microphone because (unless I'm mistaken) it said it would not require much of a hole for sound to get through, that it could be pressed right up against the enclosure and still get good sensitivity.

The enclosure is a 6"x6" "rounded pyramid" form. Similar to the following picture, but made of plastic.

The item 12642 has a microphone on the board.
You won't need the mems mic.

So I hate it when people ask to be spoon-fed, and I really wanted to figure out the coding necessary for this project, but with the Thanksgiving "break" I had, there was zero time to learn anything.

Honestly, after trying to figure out what I'm doing with this, I am overwhelmed. I've been googling "arduino sound level sensing" in various forms but no one is using the breakout I am and while I am knowledgeable in many realms, coding and electronics are my Achilles heel.

The deadline for this project is fast approaching, (like, REAL fast) can someone point me in the right direction or would anyone mind taking a crack at the coding?

I'm not sure why the hookup guide (with code) doesn't fill the bill for you.

https://learn.sparkfun.com/tutorials/me ... okup-guide

I used the hookup guide for the unit you recommended, not the MEMS breakout. https://learn.sparkfun.com/tutorials/so ... okup-guide

Regardless, I don't know enough to make it run a NeoPixel ring (which I just today found out requires a separate 5v source) and even though I did successfully get it to light up a single LED, for some reason once it lights up, it stays lit up and will not go back under "Moderate" levels of sound.

Take into account that this cry for help is coming from someone who doesn't really know the difference between amps and volts, and who's only real-world experience with capacitors comes from 20 years ago when I discovered that if you heated them with a magnifying glass and the sun, they would explode.

I do not have confidence that I will be able to learn what I need to do this on my own by this Thursday. I fully understand that just asking someone to try to code this for me is kind of a dick move, but I'm not sure what my other options are at this point.

To be clear, there really wasn't enough time budgeted for this project from the start...yet, here I am.

Asking for someone to code it for you isn't a dick move: there are entire industries built on this very concept of "exchange cash for X service." Sometimes you simply don't have the time to get something done.

That said, I'd offer to do it for you, but I don't have the hardware and it simply wouldn't get here in time for your deadline.

Thank you for the kind words. There's a place here at school that has someone with a lot of Arduino experience, I went there yesterday but he wasn't working. I'll try again today and keep my fingers crossed.

You would think with how long the Arduino has been out and with how popular it is, there would be some program that coded a sketch for you ala WYSIWYG web page makers. I'd be willing to bet there would be a huge surge of new Arduino users if there was.

Just to update this, I was able to get some coding help from two people at my school and the project was finished in time. (barely, but that's design school, lol!)

Here's a video of it in action if anyone is interested: https://www.youtube.com/watch?v=82hQDslM6mg

It has a few things I need to change like adding in a pot and an on/off switch. If I ever decide to make it an actual product there will need to be a lot more finessing of the the threshold requirements such as sound frequency and duration, but overall I'm pretty happy with how it came out for such a short turnaround time.

Thanks for the help here!