ESP32 and microphone board?

juuheli
Posts: 1
Joined: Sun Nov 22, 2020 5:29 pm

ESP32 and microphone board?

Postby juuheli » Sun Nov 22, 2020 5:44 pm

Hey guys.

I'm trying to build a project that uses voice commands to switch lights off. I think I'm best off using TensorFlow Lite to achieve this and I have Lolin D32 board already and figured the relays needed. I only need (to my understanding) a microphone breakout board (hardware-wise that is). I've looked at a couple of I2C microphone boards such as INMP441 and ICS-43434 but I understand INMP441 is outdated and shouldn't be used, whereas ICS-43434 is difficult to get to Finland. I'd hope to find it on Amazon (usually the fastest and most reliable shipping here imo) and ~ $10 budget. Another alternative is SPH0645LM4H from Adafruit but their shipping here is extremely expensive. I've tried to look for more but couldn't find anything else.

Does anyone have any other products they can think of? Or maybe an alternative for an I2C board? It doesn't need to be one but I couldn't find anything that wouldn't cost a lot like an actual microphone.

I also gather that if I use Wi-Fi on the board, I can only use the weaker ADC so it wouldn't be accurate and I'd need to be close to the microphone board. To fix this (and be able to give clear commands from like <2 meters) I'd need an external one like MCP3208, right?

EDsteve
Posts: 10
Joined: Fri May 06, 2022 4:53 pm

Re: ESP32 and microphone board?

Postby EDsteve » Mon Nov 21, 2022 5:06 am

The INMP441 is obsolete and is not produced any more. "Unfortunately" you can still buy the module almost everywhere but this will not be the INMP411. Even they call it INMP411.
I had a project where i needed to build 30 recorders and ordered 30pcs INMP411 from different distributors. It turns out that they differ very much by sound quality and frequency spectrum.
In the attachment you can see the same recording with two INMP411 from different sellers.

So the INMP411 can only be used for fun project. But not for anything serious due to lack of consistency. You basically have no idea which MEMS is used on the board :(
Attachments
ELOC7 vs ELOCed - different quality same mic.JPG
ELOC7 vs ELOCed - different quality same mic.JPG (455.01 KiB) Viewed 1386 times
ELOC7 vs ELOCed - changed the bad mic to new one - high frequencies.JPG
ELOC7 vs ELOCed - changed the bad mic to new one - high frequencies.JPG (433.94 KiB) Viewed 1386 times

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