Gravity: Offline Language Learning Voice Recognition Sensor for micro:bit / Arduino / ESP32 - I2C &

The Offline Voice Recognition Module is an efficient solution, ideal for human-computer interaction, machine learning, voice assistants and voice control projects for smart home . It is easy to use and is compatible with Arduino, micro:bit and ESP32, with detailed tutorials included. It offers plug-and-play functionality via I2C and UART interfaces. The module has 121 predefined commands commonly used in educational settings and smart home and supports 17 custom commands (e.g., recording a cat's meow for a vending machine). The module is highly integrated, including on-board speaker and microphone, providing real-time voice feedback.

Easy to Use

The offline voice module is easy to use and is compatible with existing platforms such as Arduino UNO, micro:bit and ESP32, with detailed tutorials for Arduino IDE and Makecode. It supports plug-and-play functionality via I2C and UART communications, allowing easy integration into projects.

121 Ready-to-Use Words

Built-in commands are commonly used in educational scenarios and smart home , allowing immediate use without any configuration, such as "Play music," "Open the door," "Turn on the light," "Close the window."

Self-learning function

The self-learning function is user-friendly, allowing users to add 17 custom commands.
Any language or sound can be trained as a command, offering great flexibility for interactive audio projects.
Teaching new commands to the device is simple:

• Activate the learning mode with the activation word.
• Say "Command word to learn."
• Repeat the desired command three times.

After these steps, the device will have learned the new command. Detailed instructions are provided to ensure an easy and intuitive learning process.

No Internet Connection, Increased Security

Users do not have to worry about their conversations being recorded and uploaded to the cloud. The module works perfectly in outdoor projects, schools and other environments with unstable networks. Unlike common online voice assistants, which rely on cloud platforms and require Internet access, the module ensures privacy of device data during use.

High Integration, Space Saving

The offline voice module integrates on-board speaker and microphone. High integration saves space and eliminates wiring complexity, improving project cleanliness and stability.

Real-Time Voice Feedback

Users can receive immediate recognition results during use, enhancing experience and convenience. The Offline Voice Recognition Module is an easy-to-use and highly integrated solution, perfect for various projects, offering:

• 121 built-in commands
• 17 customizable commands
• Real-time voice feedback
• Secure offline operation, with no Internet connection required

Version History and Important Information

Note: DFRobot warehouses contain both V1.0 and V1.1 versions of this module. You may receive either version. Rest assured: both versions offer the same core speech recognition functionality, performance, and key features described in this product sheet.

V1.1 (May 8, 2025)

This version includes minor iterative refinements focused on physical handling and ease of assembly:
Improved Speaker Connection: The on-board speaker connection is now a simpler plug-and-play connector (V1.0 had a soldered connection). This simplifies assembly and modifications.
Enhanced Sensor Support: Mounting holes have been added on the sensor board for more secure attachment.

V1.0 (March 2023)

The original, robust and fully functional module. It provides the full range of offline speech recognition functionality and ensures a highly effective and reliable user experience.

Features

• Easy to Use: Plug-and-play, compatible with Arduino UNO, micro:bit and ESP32.
• 121 Preprogrammed Commands: Ready for immediate use without any configuration.
• Self-Learning Function: Supports the addition of 17 custom commands.
• Offline Operation, Greater Privacy: Requires no network connection.
• High Integration: Includes on-board speaker and microphone.
• Instant Voice Feedback: Provides real-time recognition results.

Applications

• Interaction via voice recognition
• Voice-controlled terminals
• Competitions and project development

Package contains: 1 x Gravity: Offline Language Learning Voice Recognition Sensor for micro:bit / Arduino / ESP32 - I2C & UART- DFRobot

Specifically, the kit includes:

• 1 x Gravity Voice Recognition Module - I2C & UART (V1.1)
• 1 x Gravity-4P I2C/UART Sensor Connector