VC-01 & VC-02 Series Guide: Basics

Introduction

The offline voice module has many features, among which the most notable are the predefined voice commands and fast response time.

Introduction to VC-01 and VC-02 Series

The VC-01 and VC-02 series (including modules and their dev kits) are offline voice recognition modules launched by Ai-Thinker. Both use the Unisound Fengniao M (US516P6) voice recognition chip, offering high reliability and broad applicability.

These modules support analog microphone input and dual-channel DAC output, feature 2MB Flash and 242KB SRAM built-in, and integrate multiple voice noise reduction technologies to achieve high recognition accuracy with low-latency response.

They support bilingual (Chinese and English) control, suitable for smart homes, voice interaction, IoT, and similar application scenarios.

Both VC-01 and VC-02 development kits use the same PCB baseboard, with only the module package size differing (as shown in the figure above).

The modules and dev kits support up to 150 offline voice recognition commands. They also provide 5 GPIO outputs, I2C, PWM, DAC, and UART outputs. GPIO outputs can control simple switches, while other protocols can be used to connect to external MCUs for handling complex commands.

Compared to VC-01, VC-02 is better suited for users with strict requirements on board size. The corresponding development board schematics can be found in the VC-01 or VC-02 development kit specifications.

Additionally, Ai-Thinker’s forum provides comprehensive development resources for the VC-01 and VC-02 series offline voice modules (as shown in the figure below).

Unboxing the VC Series Development Kit

Since the baseboards of VC-01-dev-kit and VC-02-dev-kit are identical, the following demonstration will use the VC-02-dev-kit unless otherwise noted.

The VC-02-dev-kit contains three modules:

• The speaker module
• The microphone module
• The VC-02-dev-kit mainboard

The dev kit is powered via a Micro-USB port. The development board has two interface slots:

• The lower interface is for the speaker output
• The upper interface is for the microphone input

When connecting the microphone and speaker, make sure to align the interfaces properly. Thanks to the foolproof design, the connectors can be easily plugged in without error. The back of the dev kit is shown in the figure below.

Conclusion

In this article, we briefly introduced the offline voice module and its application scenarios, with a focus on the Ai-Thinker VC-01 and VC-02 series modules and their development kits, including parameter comparisons and available development resources.

We also provided an unboxing experience of the VC-02-Kit, highlighting its hardware features to give developers practical insights.

In the next article, we will introduce the pin definitions and peripheral expansions of the VC series, as well as test the factory firmware.