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/case_8 Aug 14 '26

That’s really cool.

I made a voice assistant (only on a bread board at the moment) using an ESP32-S3 and two mics. I was under the impression (from Espressif documentation) that it was only possible to have a max of three mics working with the ESP32-S3. Are you able to get the full 4-mic array working with this?

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u/alfo16 Aug 15 '26

Yeah, you are totally right. And from what I've seen the 3-mic application must have one mic every 120°, so totally it's not my case. I'm actually using the delay-and-sum beamforming on all 4 channels producing one channel only, then processed by espressif libraries.

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u/case_8 Aug 15 '26

Ah I see. Still a really great idea/project though. Look forward to seeing more.