ESP32 RTSP Mic for BirdNET-Go

ESP32-C6 + I2S MEMS microphone streamer that exposes a mono 16-bit PCM audio stream over RTSP, designed as a simple network mic for BirdNET-Go.

• Latest firmware: v1.6.0 (2026-02-13)
• Target firmware: esp32_rtsp_mic_birdnetgo (Web UI + JSON API)
• Changelog: esp32_rtsp_mic_birdnetgo/CHANGELOG.md
• One-click web flasher (recommended): https://esp32mic.msmeteo.cz (Chrome/Edge desktop, USB-C data cable)

Quick Start (EN)

1. Open https://esp32mic.msmeteo.cz.
2. Click Flash, select the USB JTAG/serial device, wait for reboot.
3. On first boot the device starts AP ESP32-RTSP-Mic-AP (open). Connect and finish Wi-Fi setup at 192.168.4.1 (captive portal).
4. Open the Web UI: http://<device-ip>/ (port 80).
5. RTSP stream (BirdNET-Go/VLC/ffplay): rtsp://<device-ip>:8554/audio (or rtsp://esp32mic.local:8554/audio if mDNS is enabled).

Wiring (XIAO ESP32-C6 + ICS-43434)

ICS-43434 signal	XIAO ESP32-C6 GPIO	Notes
BCLK / SCK	21	I2S bit clock
LRCLK / WS	1	I2S word select
SD (DOUT)	2	I2S data out from mic
VDD	3V3	Power
GND	GND	Ground

Tips:

• Keep I2S wires short; for longer runs use shielded cable to reduce EMI.
• Some XIAO ESP32-C6 revisions use an RF switch (GPIO3/GPIO14). If you use a different board or internal antenna only, you may need to comment out the antenna GPIO block in setup().

Test The RTSP Audio

• VLC: Media → Open Network Stream → paste the RTSP URL.
• ffplay: ffplay -rtsp_transport tcp rtsp://<device-ip>:8554/audio
• ffprobe: ffprobe -rtsp_transport tcp rtsp://<device-ip>:8554/audio

If VLC/ffplay works, BirdNET-Go will typically work too (just use the same RTSP URL as your input).

Highlights (v1.6.0)

• Web UI (English) on port 80 with live status, logs, and controls
• JSON API for automation
• MQTT + Home Assistant Discovery: richer diagnostics entities (boot reason/counter, Wi-Fi reconnect count, stream uptime/client count, firmware build)
• MQTT publish interval configurable in UI/API (default 60 s, range 10..3600) with immediate event-driven state publish
• Stream schedule (start/stop local time) with overnight window support (for example 22:00-06:00)
• Fail-open schedule policy when time is unavailable (stream stays allowed instead of blocking)
• Schedule edge-case rule: Start == Stop is an explicit empty window (stream blocked always)
• Time & Network UI extended with stream schedule controls, status, and help tooltips
• Time & Network UI shows current Local time, UTC time, and applied time offset
• Optional deep sleep outside the stream schedule window (conservative mode + double-confirm enable in UI)
• Deep sleep safety policy: never sleeps when time is unsynced, during startup grace, or with active stream/client
• Max one deep-sleep cycle is 8 hours (for lower wake-up overhead / better solar use)
• Deep sleep wakes with a 5-minute guard before stream window to reduce RTC-drift edge issues
• After deep-sleep timer wake, logs include retained sleep snapshot (cycle, planned sleep, entered time, schedule, offset)
• Logs panel keeps manual scroll position when reading older logs (auto-follows only near bottom)
• Mobile UI: top header/RTSP links now wrap correctly (no horizontal overflow scrollbar)
• Auto-recovery (manual/auto packet-rate thresholds)
• Scheduled reset, CPU frequency control
• Thermal protection with latch + acknowledge
• High-pass filter (HPF) configurable (reduce rumble)
• RTSP keep-alive (GET_PARAMETER), single client

Web UI screenshot:

Recommended Hardware (TL;DR)

Part	Qty	Notes	Link
Seeed Studio XIAO ESP32-C6	1	Target board (tested)	AliExpress
MEMS I2S microphone ICS-43434	1	Supported/tested reference mic	AliExpress
Shielded cable (6 core)	optional	Helps reduce EMI on mic runs	AliExpress
220 V -> 5 V power supply	1	>= 1 A recommended for stability	AliExpress
2.4 GHz antenna (IPEX/U.FL)	optional	If your board/revision uses external antenna	AliExpress

Notes:

• Links are provided for convenience and may change over time. Always verify the exact part number (for example ICS-43434) in the listing before buying.

Tips & Best Practices

• RTSP is single-client (only one connection at a time).
• Wi-Fi: aim for RSSI > -75 dBm; try buffer >= 512 for stability.
• Placement: keep the mic away from fans/EMI; shielded cable helps for longer runs.
• Security: keep the device on a trusted LAN; do not expose HTTP/RTSP to the public internet.

High-Pass Filter (Reduce Low-Frequency Rumble)

• Default: ON at 500 Hz (since v1.4.0).
• Typical cutoff range: 300-800 Hz depending on your environment.
• UI: Web UI -> Audio -> High-pass + HPF Cutoff.
• API:
  • Enable/disable: POST /api/set with body key=hp_enable&value=on|off
  • Set cutoff (Hz): POST /api/set with body key=hp_cutoff&value=600
  • For mutating calls, send header X-ESP32MIC-CSRF: 1 (used by Web UI).

Compatibility

• Target board: ESP32-C6 (tested with Seeed XIAO ESP32-C6).
• Other ESP32 variants may work with pin/I2S tweaks.
• Other I2S mics may be possible, but ICS-43434 is the supported/tested reference.

More Docs (Build, API, Internals)

See esp32_rtsp_mic_birdnetgo/README.md.