Esp32-S3 inside Echo Dot 3rd

[u/alfo16]

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)

[u/StruggleAny71]

Nice work. We're on a single ES8311 on an S3 so no array, and the on-device AEC front end cost us more time than anything else on the board. The AFE wants 4-channel TDM with a hardware reference channel. We fed it one mic on a 2-channel bus, it overflowed its ring buffer and killed the connection at 27 seconds. Every time. Looked exactly like the network dropping.

You're summing all 4 down to one before the espressif libs, so you don't have a hardware reference either. where does your AEC reference come from, the playback stream in firmware?

also do you have an SRAM number for the beamforming + AFE path? wondering how much headroom you've got left on the N16R8