Help with VU meter and decibel meter

Hello people, I'm pretty new to Arduino and I need a little (bigger) help. I need to make project that will record sound from my VMA309 sound sensor VMA309: MICROPHONE SOUND SENSOR MODULE – Velleman – Wholesaler and developer of electronics and output it to my 9 LED diodes that will act like VU meter- showing intensity of sound- and to LCD screen like this in DECIBELS.
It's practically standard I2C LCD for Arduino just with that keypad thing.
So I would appriciate any kind of hint or help, in technical or software way :slight_smile: :slight_smile:

What do you need help with?

that will record sound

I assume you don't really need to "record" the sound? You just want to sense/measure the loudness, right?

If you need help with the SPL (sound pressure level) measurements, search the forum for "SPL". This has been discussed and done before.

You will need an SPL meter to calibrate the one you're building. You can get a cheap one for under $50 USD.

There are several "parts" to your project and you need to take them one at a time -

You can start with reading the output from your sound sensor and sending it to the serial monitor (use Analog Read Serial Example). You can take the average or peak readings and try to correlate those readings to loudness. For example, take 100 readings per second and average those, or find the peak over a 1-second period, etc. (The readings will "look random" before finding an average or sorting-out the peaks because it's a continuously varying sound wave with one positive and one negative peak per-cycle.)

Once you get that calculated and calibrated you can display dB SPL on the serial monitor.

Then, you can work on activating the LEDs. (That should be easy.)

Finally, you can write the data to your LCD instead of (or in addition to) the serial monitor.