Ai-Thinker VC-02-Kit | Best Offline Voice Recognition Board

Ai-Thinker VC-02-Kit | Best Offline Voice Recognition Board is a low-cost, low-power speech recognition development board that processes offline voice commands locally without requiring an active internet connection. Powered by the USiC VC-02 module and a built-in neural network processing unit (NPU), this board accurately identifies custom wake words and command phrases with minimal latency. Consequently, designers can maintain user privacy and eliminate network dependency in smart home devices. The kit includes an onboard microphone, a speaker header, and an integrated CH340 USB-to-UART converter to streamline firmware flashing and debugging. Furthermore, engineers can easily connect this module to microcontrollers like Arduino, ESP32, or STM32 using standard serial communication. Therefore, you should choose the VC-02-Kit to effortlessly add voice control functionality to your embedded systems and IoT projects.

Key Features:

• Offline Voice Processing: Processes voice recognition locally on the board, eliminating the need for cloud services, Wi-Fi connections, or external API subscriptions.
• Integrated NPU Acceleration: Features a high-efficiency NPU hardware core that supports local neural network algorithms for high command recognition accuracy and low response time.
• Onboard USB-to-Serial Port: Includes a CH340 USB-to-UART interface, enabling direct programming and debugging via a standard Type-C USB cable.
• Speaker and Microphone Interfaces: Comes with a built-in electret microphone and a 2-pin header to drive an external 8 Ω 1W/2W speaker directly.
• Customizable Command Sets: Allows developers to configure custom wake words and control commands through the official Ai-Thinker online firmware generation tool.

Technical Specifications:

• Main Processor: VC-02 Module (32-bit RISC Core with NPU)
• Operating Voltage: 5.0 V (via USB Type-C) or 3.3 V to 5.0 V (via header pins)
• Working Current: ≥ 200 mA (Peak current when driving a speaker)
• Flash Memory: 4 MB SPI Flash
• Supported Voice Commands: Up to 150 offline local commands and wake words
• Communication Interfaces: UART, I2C, PWM, and GPIO
• Operating Temperature Range: −40°C to +85°C

Mechanical Specifications:

• Board Material: High-quality FR-4 PCB
• USB Connector: USB Type-C Female
• Header Pitch: Standard 2.54 mm pitch for easy breadboard integration
• Speaker Interface: 2-pin XH2.54 connector

Dimensions:

• Board Length: ≈ 42.0 mm
• Board Width: ≈ 32.0 mm
• Overall Height: ≈ 12.0 mm (Including headers and USB port)
• Weight: ≈ 10 g

Pinout and Wiring:

• 5V / 3V3: Main power input pins; connect to a 5.0V or 3.3V supply rail.
• GND: Ground reference pin; connect to system power supply ground.
• TX1 / RX1: Primary UART pins used for serial communication with host microcontrollers.
• SPK+ / SPK-: Output connection pins for an external 8 Ω speaker.
• GPIO Pins: Configurable general-purpose I/O pins for direct relay drive or LED status indication.
• Wiring Note: However, always ensure the supply voltage matches the operating limits to prevent damage to the onboard VC-02 module.

Datasheet Reference:

• Download Ai-Thinker VC-02-Kit Specification Datasheet

Commonly Used in:

• Smart Home Automation: Controlling smart lights, fans, air conditioners, and curtains via direct spoken commands.
• Educational Electronics: Teaching students and hobbyists the fundamentals of machine learning and offline audio processing.
• Assistive Technology: Building hands-free control interfaces for individuals with limited mobility.

Applications:

• Hands-Free Appliance Control: Activating home appliances using simple voice prompts without network latency.
• Interactive Toys and Robotics: Enabling voice interaction in educational robots and electronic toys.
• Industrial Voice Prompt Systems: Delivering audio announcements and receiving operational commands on factory floors.

Equivalent Models:

• Ai-Thinker VC-01-Kit: An earlier variant in the VC series featuring a slightly different form factor and pin layout.
• Elechouse Voice Recognition Module V3: A widely used alternative offline speech recognition board, however, it generally costs more and offers fewer command slots.
• LUATOS Air780E with Voice: A cellular module alternative that provides voice features alongside network connectivity.

Package Includes:

• 1 x Ai-Thinker VC-02-Kit Offline Voice Recognition Development Board