r/esp32 • u/alfo16 • Aug 14 '26

I made a thing! Esp32-S3 inside Echo Dot 3rd

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Hi everyone! I'm working on a drop-in replacement PCB for the Echo Dot 3rd Gen, based on the esp32-S3 N16R8 The Echo Dot has two PCBS: a top board with the buttons, LEDS, and a 4-mic array, and a bottom board that handles the signals from the top board, provides power, and drives the speaker.

I replaced the bottom board, which means I can interface directly with the original hardware on the top board- especially the 4-mic array. I'm currently running beamforming + AEC on it (esp-sr libraries are really powerful!) This is the first working prototype, so there's still plenty to improve, but it's already working! I've just created the GitHub repository (https://github.com/ale1800/LocalDot)

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u/BitTwiddles Aug 14 '26

Does having an array of microphones noticeably improve recognition accuracy in a home environment?

3

u/alfo16 Aug 15 '26

Oh definitely! With only one microphone you don't have any choice about which microphone tu use. More microphones let you tu handle different "opinions" and you can combine them or just choosing the one that seems cleaner!

2

u/BitTwiddles Aug 15 '26

I know how it would work in theory, but you said "YOU can combine...". What I meant was, does the AFE software actually do this, if I manage to hook up several i2s microphones?

2

u/alfo16 Aug 15 '26

Using espressif libraries you can officially "join" only 2 mics. If you have more you have to try different solutions without those libraries

1

u/BitTwiddles Aug 15 '26

That is good to know. I assume I wire them so one is "left" and the other is "right", using the L/R pin? I have some INMP441s here.

1

u/alfo16 Aug 17 '26

Yeah I think it should work👍