PART · A1-SLWF-03Addressable-LED controller · ESP32 · Sound-reactive WLED · SMLIGHTREV 2.1 · 2026·07
Datasheet · Product reference
Pixel LEDs,
with a voice.
ESP32 addressable-LED controller pre-flashed with sound-reactive WLED. Digital mic, IR receiver, capacitive button, eight LED channels, 5–24 V — all on a 57 × 30 × 23 mm board. Plug-and-flash with no BOOT-button dance.
01
Abstract.
Control
- Wi-Fi 2.4 GHz · 802.11 b/g/n
- On-board I2S microphone (ICS-43434)
- 38 kHz IR receiver
- Capacitive touch button
- Home Assistant · MQTT · native WLED
Power
- USB-C · 5 V
- DC barrel · 5 / 12 / 24 V
- Screw terminal · 5 / 12 / 24 V
- Reverse-polarity protected
- Over-voltage protected
Output
- 2 × screw-terminal channels
- 6 × DIY-pinout channels
- WS2812B · WS2811 · WS2813 · WS2815
- SK6812 · APA102 · LPD8806 · WS2801
- ≈ 2000 LEDs @ 30 FPS
Firmware
- Pre-flashed WLED-SR
- ESPHome compatible
- ESPHome · BT Proxy
- Tasmota · community builds
- Plug-and-flash (auto-boot)
02
Block diagram. Signal flow.
Inputs (Wi-Fi, mic, IR, button, USB-C / DC / screw) → ESP32 → outputs (2 screw-terminal LED channels + 6 DIY channels, plus Wi-Fi back to Home Assistant / MQTT).
03
Mechanical & pin-out.
Mechanical — top view
Mounting hole spacing 51 × 24 mm · M3 · height 23 mm with tallest component.
DIY pin-out — 8-pin bottom header
| Pin | GPIO | Function | Notes |
|---|---|---|---|
| 1 | GPIO2 | LED CH 3 | Level-shifted 3.3 → 5 V |
| 2 | GPIO4 | LED CH 4 | Level-shifted |
| 3 | GPIO5 | LED CH 5 | Level-shifted |
| 4 | GPIO12 | LED CH 6 | Strapping — avoid pull-high at boot |
| 5 | GPIO13 | LED CH 7 | — |
| 6 | GPIO14 | LED CH 8 | — |
| 7 | GND | Ground | Common with power inputs |
| 8 | 3V3 | 3.3 V rail | 200 mA max for user loads |
04
Electrical characteristics.
TABLE 1.Recommended operating conditions & electrical limits2026·07
| Parameter | Min | Typ | Max | Unit | Notes |
|---|---|---|---|---|---|
| V_CC (USB-C) | 4.75 | 5.00 | 5.25 | V | USB-IF spec |
| V_CC (DC / screw) | 4.75 | — | 25.2 | V | 5 / 12 / 24 V nominal |
| I_CC (idle) | — | 75 | 110 | mA | Wi-Fi connected, LEDs off |
| I_CC (mic + Wi-Fi) | — | 110 | 160 | mA | Sound-reactive effects |
| I_out per channel | — | — | 5 | A | Screw-terminal, 25 °C, momentary |
| V_logic (out) | 3.1 | 3.3 | 3.5 | V | Pre-level-shifter output |
| LED refresh rate | — | 30 | 60 | FPS | Typical WS281x, depends on chain length |
| LED chain length | — | 1500 | 2000 | LEDs | Single channel, 30 FPS target |
| T_op | +5 | +25 | +35 | °C | Humidity < 60 % RH non-condensing |
| T_storage | −20 | — | +60 | °C | Dry environment |
| ESD (HBM) | — | — | ±2 | kV | Per JS-001-2017 |
05
Supported LED chipsets.
| Chipset | Protocol | V_strip | Max refresh | Colours | Notes |
|---|---|---|---|---|---|
| WS2812B | Single-wire | 5 V | 400 Hz | RGB | Most common |
| WS2811 | Single-wire | 5 / 12 V | 400 Hz | RGB | Cabinet lighting |
| WS2813 | Single-wire · dual-data | 5 V | 400 Hz | RGB | Fault-tolerant |
| WS2815 | Single-wire · dual-data | 12 V | 400 Hz | RGB | Long runs |
| SK6812 | Single-wire | 5 V | 400 Hz | RGBW | White ambient |
| APA102 | SPI · clock + data | 5 V | 20 kHz | RGB | High-FPS POV |
| LPD8806 | SPI · clock + data | 5 V | 2 MHz | RGB | Legacy |
| WS2801 | SPI · clock + data | 5 V | 1 MHz | RGB | Legacy Adafruit alt. |
06
Firmware support matrix.
| Feature | WLED-SR | ESPHome | BT Proxy | Tasmota | Custom |
|---|---|---|---|---|---|
| Addressable LED output | ● | ● | — | ● | ● |
| Sound-reactive effects (mic) | ● | ● | — | — | ● |
| IR remote codes | ● | ● | — | ● | ● |
| Capacitive button | ● | ● | — | ● | ● |
| HA Voice Assistant mic | — | ● | — | — | ● |
| Bluetooth-LE proxy | — | — | ● | — | ● |
| Home Assistant native integration | ● | ● | ● | — | ● |
| OTA updates | ● | ● | ● | ● | ● |
07
Application notes.
AN-01 · Power
Powering a 12 V WS2815 strip from a single supply
Wire the 12 V PSU directly to the screw-terminal
V_IN; the controller's on-board regulators handle 5 V and 3.3 V internally. Share the strip's GND with V_IN GND on the same terminal. No level-shifter required for single-wire strips.AN-02 · Voice
Using SLWF-03 as a Home Assistant voice-assistant mic
Flash the ESPHome
i2s_audio component pointing at bck_pin: GPIO25, ws_pin: GPIO26, din_pin: GPIO22. The SLWF-03 advertises as a remote microphone — HA auto-discovers it for the Voice Assistant pipeline.AN-03 · BTProxy
Turning the controller into a Bluetooth-LE proxy
Use the on-board flasher to load the pre-built ESPHome BTProxy firmware. The SLWF-03 then relays BLE sensor packets to HA across the whole building — useful for Xiaomi, Govee, and Switchbot devices positioned far from the HA host.
AN-04 · Matrix
Building an 8-channel addressable matrix
Expose CH 3–8 on the DIY pinouts through an external 74HCT245 level-shifter (optional; the on-board 3.3 V logic works with most 5 V strips). Configure in WLED as matrix or in ESPHome as eight independent
light.addressable_light entities.AN-05 · Enclosure
Enclosure design considerations
Mounting-hole spacing is 51 × 24 mm · M3. Leave ≥ 5 mm clearance on the long sides for the USB-C and LED terminals; leave ≥ 10 mm on the top edge for the DC barrel and power screw terminal. Don't enclose the microphone port — it requires direct air coupling for sound reactivity.
AN-06 · OTA
Upgrading without touching the BOOT button
The USB-to-UART bridge supports ESP32 autoboot — drop a new firmware binary via the web flasher and it will reset + flash automatically. No BOOT button dance, no external programmer. Works for WLED, ESPHome, Tasmota, and custom ESP32 binaries.
08
Owner citations.
“I've built a dozen sound-reactive setups over the years. The SLWF-03 is the first one that just worked— on-board mic, no soldered 5 V jumpers, no ground-loop debugging.”1
“Four of these drive the entire under-cabinet and behind-TV lighting in my house. Sync is bit-perfect across all four — the WLED beat-sync is magic.”2
— selected from r/WLED, the SMLIGHT Discord, and smarthomescene.com
- u/pixel_hobbyist · r/WLED · 2025-02-18 · thread:
slwf-03 first-time-setup - Intermit.Tech review ·
intermit.tech/smlight-slwf-03-review· 2024-11-06 - SMLIGHT Discord ·
#slwfchannel · multi-thread owner synthesis
09
Ordering information.
TABLE 4.Part numbers & channelsShenzhen Baishi Video Technology Co., Ltd. · CN
| Part number | Description | Stock |
|---|---|---|
| A1-SLWF-03 | Retail box — device, quick-start, sticker | In stock · ships in 48 h |
| A1-SLWF-03-KIT | Retail box + IR remote + USB-C PSU | In stock |
| A1-SLWF-03-T10 | 10-pack (trade channel) | On request |
| A1-SLWF-03-BULK | 100+ unit bulk, no retail packaging | On request |
A1-SLWF-03 · Datasheet · Rev 2.1 · 2026·07smlight.tech/products/slwf-03 · SMLIGHT