Lierda XiaoDa Application Guide_Rev0.1

Chinese

ChangeList

[!NOTE] Note Please remove the enclosure and check the silkscreen model and version on the main board to confirm that your development board version corresponds to the application guide document.

Xiaoda is an embedded core module integrating voice recognition, audio playback, and intelligent interaction, specifically designed for smart toys, educational devices, and interactive terminals. This movement incorporates a main control chip, audio system, and power supply module, enabling voice wake-up, conversational interaction, content playback, and other functions.

This application guide will help you get started quickly with Xiaoda and provide detailed information about this development board.

This guide includes the following content:

  • Hardware Version: Introduces hardware version history and known issues.

  • Getting Started: Provides a brief introduction to the development board and hardware/software setup guide.

  • Hardware Reference: Provides detailed information about the development board hardware.

  • Software Reference: Provides detailed information about the software framework, modules, and configuration methods.

  • Related Resources: Lists links to related documents.

Hardware Version

This document only applies to the Xiaoda main board model: L-CT4IT00-YP00W-03A_V04.

PCB Model

PCB Version

Change Log

L-CT4IT00-YP00W-03A

V04

/

Getting Started

This section provides a brief introduction to Xiaoda, explaining how to flash firmware and related preparation work.

Component Introduction

Main Components (TOP)

Description

L-CT4IT00-YP00W-03A_V04

Main Board PCB

shell

Enclosure

103040A1

Battery

JMO-627BA283H-1AXD63

Microphone

2831NROOO-4P25D13H

Speaker

13P023M

Antenna

L-CT4IT00-YP00W-03A_V04 (Main Board PCB)

shell(Enclosure)

103040A1 (Battery)

JMO-627BA283H-1AXD63 (Microphone)

2831NROOO-4P25D13H (Speaker)

13P023M (Antenna)

Main Board Introduction

The main components and interfaces of L-CT4IT00-YP00W-03A_V04 are described below:

Main Components (TOP)

Description

Onboard MIC (Reserved)

Either this or the microphone connector can be used

Speaker Connector

1.5mm/2PIN connector socket for connecting 4Ω/3W speaker

Battery Connector*(1)*

1.5mm/3PIN connector socket, compatible with battery 103040A1

BOOT Test Point

Used to force entry into download mode when the module is bricked

Motor/Servo Connector*(2)*

1.25mm/6PIN connector socket, provides 2-channel PWM/power/H-bridge differential output, use as needed

GX8006A

Offline voice chip with local AEC (Acoustic Echo Cancellation) and custom wake word capability

CST8302A

AB/D class amplifier, AB class recommended for better AEC performance

CL4056D

Charge management chip, suitable for 4.2V battery, NTC recommended R25=100KΩ

Nor flash

Nor flash chip, 32Mbit, suitable for 3.3V systems

TC118S

H-bridge driver chip

USB Connector

Type-C interface connector for power supply, charging, communication, and download

Reset Side Button

Reset, used to reset the module

Main Components (BOT)

Description

Antenna Socket

IPEX-1 generation socket, compatible

Extension Button Connector*(3)*

1.25mm/6PIN connector socket, provides PWRKEY and 3 custom buttons (2 pins can be multiplexed as UART)

NT26F6D0 Module

Cat.1 module, supports OPEN application development

FPC Connector*(4)*

0.5mm/16PIN FPC connector for connecting binocular screen adapter board

Microphone Connector

1.25mm/2PIN connector socket for connecting electret microphone

Power Button

Pwrkey, used for system power on/off

RGB LED

RGB indicator light, indicates module working status

Green LED

Charge complete indicator, stays on when fully charged

Red LED

Charging status indicator, stays on during charging

SIM Card Slot

Nano-SIM card slot connector for SIM card reading

[!NOTE] Note

  1. When using the battery connector, ensure the battery terminal wire sequence corresponds to the connector wire sequence

  2. When using the motor/servo connector, pay attention to the wire sequence; motors and servos are not included in the Xiaoda product package

  3. When using the extension button connector, pay attention to the wire sequence; the button extension board is not included in the Xiaoda product package

  4. When using the FPC connector, pay attention to the wire sequence; the binocular screen adapter board is not included in the Xiaoda product package

Enclosure Interfaces

Key enclosure interfaces are described below:

Interface (TOP)

Description

Speaker

Speaker sound mesh

Type-C

Type-C interface, connects PC and Xiaoda for power supply, charging, communication, and download

Charging Indicator

Indicates charging status: red light during charging, green light when fully charged

RGB Indicator

Indicates working status

Reset

Reset hole, use a SIM eject pin to reset the system

Interface (Side)

Description

MIC

Microphone pickup hole

Power Button

Long press to power on when off, long press to power off when on

Interface (BOT)

Description

MIC Interface

Used when connecting an external microphone, pay attention to wire sequence

Extension Button Interface

External button extension, IO1/IO2 can be multiplexed as UART, pay attention to wire sequence

Motor/Servo Interface

External motor/servo, built-in H-bridge driver circuit, M+/M- can connect DC motor, pay attention to wire sequence

Start Using

Visually inspect the product appearance for integrity before powering on, ensuring no obvious damage.

Required Hardware

  • Xiaoda complete unit

  • Type-C data cable*

  • Computer (Windows, Linux, or macOS)

[!NOTE] Note Some USB data cables only support power supply and charging, and cannot communicate or download. Please ensure the USB data cable you are using can download firmware.

Hardware Power On

A USB data cable is required for power supply, communication, and flashing. Connect the PC and Xiaoda with a USB data cable, then long press the power button for more than 3 seconds.

Driver Installation

For driver installation, please refer to Lierda EigenComm Cat.1 bis Module USB Driver Installation Guide. After installation, you can see the Lierda USB port in Device Manager.

Indicator Lights

Xiaoda indicates charging and operating status through the charging indicator and RGB indicator.

Charging Indicator

  • When USB is not connected, the charging indicator is off

  • When USB is connected, the charging indicator shows red, indicating normal charging

  • When USB is connected, the charging indicator shows green, indicating fully charged

RGB Indicator

  • When powered off, the RGB indicator is off

  • When powered on, the RGB indicator shows solid green during normal operation

  • When powered on, the RGB indicator flashes blue during voice interaction

  • When powered on, the RGB indicator shows solid red during abnormal status (e.g., network error)

  • When powered on, the RGB indicator flashes green 3 times before shutdown

Hardware Reference

Functional Block Diagram

The Xiaoda functional block diagram is shown below.

Power Supply Methods

The main board is designed with a power switching circuit and can be powered by the following methods:

  1. Powered by Battery The device has an integrated 3.7V lithium battery. Press the power button for 3 seconds to power on.

  2. Powered by Type-C Port Insert the Type-C USB data cable into the USB interface. The system power will automatically switch to Type-C power supply. Press the power button for 3 seconds to power on.

Charging Circuit

CL4056D maximum charging voltage is 4.2V. NTC recommended to use batteries with R25=100KΩ, with a designable charging range of 0~45℃. When R25=10KΩ, the designable charging range is 0~50℃. As shown in the reference circuit, paired with the 103040A1 battery (R25=10KΩ, B25/50=3435), the designed charging temperature range is 0.46℃~50.22℃. For specific calculation methods, see the table below: NTC Calculation Tool(XLSX)

USB Interface

The CC1/CC2 pins of the USB Type-C connector are pulled down to ground through 5.1kΩ resistors by default, configuring the device as a charge-only Sink/Upstream Facing Port (UFP).

SIM Card Interface

In addition to the SIM card slot, the main board also reserves a chip SIM card footprint. The two overlap in PCB position, and the chip SIM card is used by default. The chip SIM card provides 500MB of data per month, valid for one year.

RF Interface

The RF interface reserves an IPEX Gen-1 socket with a reserved π-type matching network. If the antenna needs to be replaced, the matching can be adjusted.

Button Extension Interface

Please note that all button extension IOs have special usage:

  1. The basic function of PWRKEY is as a power on/off button. After powering on, the press duration can be adjusted for use as a function button, e.g., short press for conversation, long press for shutdown

  2. KEY_FUNC is the only button that can be multiplexed as wakeup, with higher interrupt priority. It can also be multiplexed as AGPIO, maintaining state during module sleep

  3. IO1/IO2 are general-purpose IOs with lower interrupt priority, and can be multiplexed as UART for debugging convenience

Motor/Servo Interface

The module provides 4 different PWM channels for motor and servo driving, supporting simultaneous connection of 1 DC motor and 2 servos.

Audio Interface

Offline Voice Chip

The offline voice chip GX8006A communicates with the module via UART and connects RST/BOOT/INT control pins. Users can perform flashing, playback, recording, and other operations on the GX8006A chip through the NT26F6D0 module.

The GX8006A chip supports local AEC. The AEC reference circuit feeds back from the amplifier output through voltage division and DC blocking to GX8006A’s MIC1, performing echo cancellation through AD sampling. If using a Class-D amplifier, the reference path requires multi-stage filtering.

Microphone Interface

The microphone connector inside Xiaoda already has a microphone inserted. If you need to connect another electret microphone externally, please pay attention to the terminal wire sequence. The microphone cannot be driven if the polarity is reversed.

Speaker Interface

The amplifier gain should match the peak-to-peak value of the preceding audio output and the speaker to avoid volume being too low or clipping distortion. Differential input is recommended for audio input to improve audio anti-interference capability. The amplifier is recommended to operate in Class-AB mode to improve AEC reference performance.

Indicator Light Interface

RGB Indicator Light

The RGB LED communication interface complies with WS2812 timing.

Charging Indicator Light

The charging indicator lights up when USB is connected: red light during normal charging, green light when fully charged.

Software Reference

Software Overview

The Xiaoda software is based on the OpenCPU development framework for the L-CT4IT00-YP00W-03A_V04 hardware, adopting an event-driven Job scheduling architecture to implement voice wake-up, AI conversational interaction, network management, power management, and other functions.

  • Software Version: V02.00.01

  • AI Platform: Coze Real-time Voice Conversation

  • Audio Codec: Opus, 16KHz sampling rate

  • Communication Protocol: WebSocket (wss)

Software Architecture

┌───────────────────────────────────────────────────┐
│                    user_main.c                    │
├───────────────────────────────────────────────────┤
│                  app_framework                    │
│  ┌──────────┬──────────┬──────────┬────────────┐  │
│  │ talk_job │ powerkey │ network  │ led_sidejob│  │
│  └──────────┴──────────┴──────────┴────────────┘  │
│                   global_policy                   │
├───────────────────────────────────────────────────┤
│                     peripheral                    │
│  ┌─────────┬────────┬────────┬──────┬──────────┐  │
│  │ai_connect│ audio │battery │ led  │ ldoPower │  │
│  ├─────────┼────────┼────────┼──────┼──────────┤  │
│  │ network │powerkey│location│      │          │  │
│  └─────────┴────────┴────────┴──────┴──────────┘  │
├───────────────────────────────────────────────────┤
│                  LIOT SDK / RTOS                  │
└───────────────────────────────────────────────────┘

Directory Structure

examples/CT4IT00YP00W_03/
├── src/
│   ├── user_main.c              # Application entry
│   └── app_nv.c                 # NV parameter storage management
├── inc/
│   ├── app_nv.h                 # NV data structure definition/pin definition/default config
│   └── user_main.h              # Entry header file
└── framework/
    ├── common/
    │   ├── inc/app_framework.h  # Framework interface
    │   └── src/
    │       ├── app_framework.c  # Framework initialization and Job registration
    │       ├── talk_job.c       # AI conversation Job
    │       ├── powerkey_job.c   # Power button Job
    │       ├── network_job.c    # Network management Job
    │       ├── led_sidejob.c    # LED indicator SideJob
    │       └── global_policy.c  # Global event dispatch policy
    ├── peripheral/
    │   ├── ai_connect/          # AI cloud connection (Coze WebSocket)
    │   ├── audio/               # Audio module (GX8006A control)
    │   ├── battery/             # Battery management (ADC sampling/charge detection)
    │   ├── led/                 # WS2812B RGB LED driver
    │   ├── ldoPower/            # LDO power control
    │   ├── network/             # Network registration and status management
    │   ├── powerkey/            # Power button detection
    │   └── location/            # Base station positioning
    └── resource/
        ├── audio_prompts.c      # Prompt tone Opus data
        └── audio_prompts.h      # Prompt tone enum definition

Core Framework Mechanisms

Event-Driven Model

The system adopts an event-driven architecture where all modules communicate through an event bus:

Event

Description

Source

EVT_KEY_POWER_ON

Power on event

powerkey module

EVT_KEY_POWER_OFF

Power off event

powerkey module

EVT_KEY_WAKEUP

Button wake-up

powerkey module

EVT_AUDIO_WAKEUP

Voice wake-up

GX8006A offline voice chip

EVT_AUDIO_RECORD_DONE

Recording complete (VAD silence detection)

audio module

EVT_AUDIO_PLAY_START

Start playing AI response

audio module

EVT_AUDIO_PLAY_DONE

AI response playback complete

audio module

EVT_AI_CONNECT_REQ

Request AI cloud connection

network_job

EVT_AI_CONNECTED

AI cloud connection successful

ai_connect module

EVT_AI_CONNECT_FAIL

AI cloud connection failed

ai_connect module

EVT_AI_DISCONNECTED

AI cloud disconnected

ai_connect module

EVT_AI_RESPONSE_DONE

AI response ended

ai_connect module

EVT_NETWORK_READY

Network registration successful

network module

EVT_NETWORK_FAIL

Network registration failed

network module

EVT_SIM_ERROR

SIM card error

network module

EVT_LOW_POWER

Low battery

battery module

EVT_SYSTEM_SLEEP

System sleep

idle timeout

EVT_TIMER_EXPIRED

Timer expired

framework timer

Job Scheduling

The framework supports two types of Jobs:

  • Main Job: Only one main Job is active at any time; multiple main Jobs are mutually exclusive

  • SideJob: Runs persistently in the background, receives all events, does not participate in main Job mutual exclusion scheduling

Currently registered Jobs:

Job

Type

Function

talk_job

Main Job

Full AI conversation flow: initialize audio → connect AI → record → send → receive → play

powerkey_job

Main Job

Handles power on/off, low battery shutdown, sleep

network_job

Main Job

Handles network status changes, triggers AI connection when network is ready

led_sidejob

SideJob

Controls RGB LED effects based on system status, manages idle timeout

Global Policy

The global policy determines how events are dispatched to Jobs:

  • Voice wake-up/AI connection request → Interrupt current Job, start talk_job

  • Power button/Low battery/Sleep → Interrupt current Job, start powerkey_job

  • Network status change → If current Job is not network/talk Job, start network_job

  • Audio events/AI events/Timer → Deliver to the currently active Job for handling

Core Module Description

AI Connection Module (ai_connect)

Connects to the Coze real-time voice conversation platform based on WebSocket protocol:

  • Uses libwebsockets library to establish wss connection

  • Audio uplink: PCM → Opus encoding → Base64 → JSON encapsulation and send

  • Audio downlink: JSON parsing → Base64 decoding → Opus frames → audio module playback

  • Supports chat.update to configure audio parameters and subscribe to events

  • Supports conversation.chat.requires_action to handle AI tool calls

Audio Module (audio)

Controls the GX8006A offline voice chip via UART (1Mbps):

  • Voice wake-up: GX8006A notifies the module via INT pin after local wake-up

  • Recording: GX8006A transmits PCM data via UART after AEC echo cancellation

  • Playback: Module sends Opus frames to GX8006A via UART for decoding and playback

  • Local prompt tones: power on/off, connection success/failure, wake-up, etc.

Power Management Module (ldoPower)

Controls the power supply sequence of peripheral devices:

  1. Enable AON power domain

  2. Set all power domain voltages to 3.3V

  3. Pull LDO33_EN (GPIO25) high to enable external LDO

  4. Control GX8006A power pin (GPIO26) to power up

Battery Module (battery)

[!NOTE] Note Due to missing hardware components, this feature is currently unavailable.

  • ADC sampling of battery voltage (channel 1)

  • USB insertion detection (GPIO14)

  • Low battery warning and automatic shutdown

LED Module (led)

Drives WS2812B RGB LED via SPI, supporting the following light effect modes:

Mode

Effect

Corresponding Status

LED_PATTERN_STANDBY

Solid green

Standby/Idle

LED_PATTERN_LISTENING

Flashing blue

Recording

LED_PATTERN_THINKING

Breathing blue

AI processing

LED_PATTERN_SPEAKING

Flashing blue

AI response playing

LED_PATTERN_ERROR

Solid red

Network/Connection error

LED_PATTERN_POWEROFF

Green flash 3 times

About to shut down

NV Parameter Configuration

System parameters are defined in app_nv.h:

Coze parameter configuration requires creating your own agent first. See https://www.coze.cn For the location token, please contact frontline colleagues.

Parameter

Default Value

Description

coze_token

(built-in)

Coze Platform API Token

coze_botid

(built-in)

Coze Bot ID

coze_voiceid

(built-in)

Coze Voice Character ID

chat_mode

0

Conversation mode

audio_volume

80

Volume (0~100)

sleep_wait_time_ms

60000

Idle prompt wait time

sleep_time_ms

60000

Auto shutdown time after idle

Main Flow

Power On (Long press PWRKEY)
        │
        ▼
Power Initialization (LDO/GX8006A power up)
        │
        ▼
Framework Init → Register Job/SideJob/Policy
        │
        ▼
Play power-on prompt tone
        │
        ▼
Network Registration ────────── Fail → Play connection failed prompt/LED red
        │ Success
        ▼
Play network connection success prompt
        │
        ▼
WebSocket Connect Coze ──────── Fail → Play connection failed prompt/LED red
        │ Success
        ▼
Play AI connection success prompt / Start recording
        │
        ▼
┌─── Wait for "Hello Xiaoda" voice wake-up (GX8006A local) ◀──────┐
│       │                                                          │
│       ▼                                                          │
│   Play wake-up response prompt (ding-dong)
│       │                                                          │
│       ▼                                                          │
│   Recording (GX8006A AEC + VAD)
│       │                                                          │
│       ▼                                                          │
│   VAD silence detected → Audio upload complete
│       │                                                          │
│       ▼                                                          │
│   Wait for AI response (LED thinking state)
│       │                                                          │
│       ▼                                                          │
│   Receive audio stream → Playback (LED speaking state)
│       │                                                          │
│       ▼                                                          │
│   Playback complete → Return to standby (LED green) ─────────────┘
│
├── Idle timeout → Play "Need more help?" → No response wait 10s → Play shutdown prompt → Shutdown
│
└── Long press PWRKEY → Play shutdown prompt → Shutdown

Build and Flash

Build

Execute in the SDK root directory:

#Windows build
build.bat PROJECT=CT4IT00YP00W_03 MODEM=NT26F6D0 all
#Linux build
make PROJECT=CT4IT00YP00W_03 MODEM=NT26F6D0 all

Build output: gccout/CT4IT00YP00W_03/CT4IT00YP00W_03_NT26F6D0.binpkg

Flash

  1. Connect PC and Xiaoda using a USB data cable

  2. Long press the power button to power on

  3. Use the Lierda download tool to select the CT4IT00YP00W_03_NT26F6D0.binpkg file for flashing

  4. After flashing is complete, press the Reset button or power on again