reSpeaker Lite — XIAO Accessory Guide

AI Audio Features

• Interference cancellation
• Acoustic echo cancellation (AEC)
• Noise suppression
• Automatic gain control (AGC)

Board Components

Compatible XIAO Boards

Important: The XIAO plugs INTO the reSpeaker Lite board — it is NOT a hat that plugs onto XIAO. The reSpeaker Lite is a larger board with its own USB-C port.

Pin Usage Diagram

The reSpeaker Lite does NOT use individual XIAO pins like a traditional hat. Instead, the XIAO ESP32S3 plugs into a dedicated socket on the reSpeaker board, which connects via I2S internally.

I2S Connection (Internal via Socket)

XIAO ESP32S3   | reSpeaker Function     | Protocol
---------------|------------------------|----------
I2S BCLK       | Bit Clock              | I2S
I2S LRCLK      | Word Select            | I2S
I2S DIN        | Audio Data In          | I2S
I2S DOUT       | Audio Data Out         | I2S
3V3             | Power                  | Power
GND             | Ground                 | Power

USB Connection (Standalone)

When used as a USB audio device, no XIAO is needed:

reSpeaker USB-C → PC/Raspberry Pi (UAC2 audio device)

Pin Conflict Warning

No pin conflicts

The reSpeaker Lite is a separate board — the XIAO plugs into it rather than the reSpeaker plugging onto XIAO pins. When used via USB, no XIAO pins are consumed at all.

When used with XIAO ESP32S3 via I2S, the XIAO is dedicated to the reSpeaker board and its remaining pins are accessible through the reSpeaker's breakout headers.

Compatible with ALL other accessories

• reSpeaker Lite can be used alongside any other XIAO accessory (on a different XIAO board)

Power Requirements

Firmware Modes

The reSpeaker Lite has two firmware versions:

Firmware Flashing via DFU-Util

# Install DFU-Util
# macOS:
brew install dfu-util

# Linux:
sudo apt-get install dfu-util

# Enter DFU mode:
# 1. Hold the DFU button on the reSpeaker Lite
# 2. Connect USB-C cable
# 3. Release DFU button

# Flash I2S firmware:
dfu-util -e -a 1 -D i2s_firmware.bin

# Flash USB firmware:
dfu-util -e -a 1 -D usb_firmware.bin

# Verify device is in DFU mode:
dfu-util -l

Arduino Setup & Usage (I2S with XIAO ESP32S3)

Prerequisites

1. Flash the I2S firmware onto the reSpeaker Lite (see Firmware section above)
2. Plug XIAO ESP32S3 into the reSpeaker Lite socket
3. Connect USB to the XIAO ESP32S3 (not the reSpeaker USB-C)

Required Libraries

# ESP32 I2S support is built into the ESP32 Arduino core
# No additional library installation needed

I2S Audio Capture Example

#include <driver/i2s.h>

// I2S configuration for reSpeaker Lite
#define I2S_PORT        I2S_NUM_0
#define I2S_SAMPLE_RATE 16000
#define I2S_BCLK        -1  // Auto-configured via socket
#define I2S_LRCLK       -1  // Auto-configured via socket
#define I2S_DIN         -1  // Auto-configured via socket

#define BUFFER_SIZE 1024

int16_t audioBuffer[BUFFER_SIZE];

void setup() {
    Serial.begin(115200);

    // Configure I2S
    i2s_config_t i2s_config = {
        .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
        .sample_rate = I2S_SAMPLE_RATE,
        .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
        .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
        .communication_format = I2S_COMM_FORMAT_STAND_I2S,
        .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
        .dma_buf_count = 4,
        .dma_buf_len = BUFFER_SIZE,
        .use_apll = false,
    };

    i2s_driver_install(I2S_PORT, &i2s_config, 0, NULL);

    Serial.println("reSpeaker Lite I2S audio capture ready");
}

void loop() {
    size_t bytesRead = 0;
    i2s_read(I2S_PORT, audioBuffer, sizeof(audioBuffer), &bytesRead, portMAX_DELAY);

    int samplesRead = bytesRead / sizeof(int16_t);

    // Calculate RMS volume level
    long sum = 0;
    for (int i = 0; i < samplesRead; i++) {
        sum += (long)audioBuffer[i] * audioBuffer[i];
    }
    float rms = sqrt((float)sum / samplesRead);

    Serial.print("Audio RMS: ");
    Serial.println(rms);
}

USB Audio Mode (No Arduino Code Needed)

When using USB firmware (default), the reSpeaker Lite appears as a standard USB audio device:

1. Connect reSpeaker Lite USB-C to PC/Raspberry Pi
2. Device appears as "XMOS USB Audio" in system audio settings
3. Select as input (microphone) and/or output (speaker) device
4. No driver installation required (UAC2 standard)

TinyGo Setup & Usage

TinyGo I2S Support

TinyGo has limited I2S support. For XIAO ESP32S3 with reSpeaker Lite:

package main

import (
    "machine"
    "time"
)

func main() {
    // TinyGo I2S support for ESP32S3 is experimental
    // Check tinygo.org/x/drivers for latest I2S driver availability

    println("reSpeaker Lite - TinyGo")
    println("Note: I2S support in TinyGo for ESP32S3 is limited")
    println("Consider using USB audio mode instead")

    for {
        time.Sleep(1 * time.Second)
    }
}

⚠ TinyGo Limitation: I2S driver support in TinyGo for ESP32S3 is experimental and may not be fully functional. For audio applications, the USB audio mode (no XIAO needed) is recommended, or use Arduino for I2S integration.

Communication Protocol Details

I2S Configuration

USB Audio (UAC2)

Common Gotchas / Notes

1. Not a traditional XIAO hat — The reSpeaker Lite is a larger board (35×86mm) with its own USB-C port; the XIAO plugs INTO it
2. Two firmware versions — USB firmware (default, plug-and-play) and I2S firmware (for XIAO ESP32S3 integration); must flash correct firmware for your use case
3. DFU-Util required — Firmware updates require DFU-Util command line tool; cannot be done via Arduino IDE
4. XIAO ESP32S3 only for I2S — Only the XIAO ESP32S3 (Sense) is supported for I2S audio via the socket
5. USB mode needs no XIAO — In USB mode, the reSpeaker Lite works standalone as a USB audio device
6. 5W speaker amplifier — Connect a compatible speaker to the speaker connector for audio output
7. Mute button — Physical mute button on the board mutes microphone input
8. WS2812 RGB LED — Programmable LED for visual feedback (voice activity indicator, etc.)
9. 16kHz max sampling rate — Sufficient for voice applications but not for music-quality audio

Reference Links

• Seeed Wiki: https://wiki.seeedstudio.com/reSpeaker_usb_v3/
• DFU-Util: https://dfu-util.sourceforge.net/
• XMOS XU316: https://www.xmos.com/
• Seeed Product Page: https://www.seeedstudio.com/reSpeaker-Lite-p-5928.html