Voice control has grown to be a major interface in the realms of do-it-yourself electronics, robotics, and smart-home invention; therefore, DFRobot released the Gravity Offline Language Learning Voice Recognition Sensor. Perfect wherever privacy, dependability, or offline operation are a consideration, this small, self-contained module processes voice commands without the need for internet access.
Key Features of Gravity Offline Voice Recognition Sensor:
- Extensive Built-in Vocabulary: The module comes ready with 121 pre-programmed commands commonly used in educational settings and smart-home systems — things like “turn on the light,” “play music,” “open door,” etc. These commands are immediately usable, without configuration.
- Custom Learning: If your project needs something more specific, you can define up to 17 custom commands. The learning process is user-friendly: use the wake-up word, say “learning command word”, then repeat the new command three times. After that, the module recognises the new word.
- Privacy and Offline Operation: Since the module functions totally offline, voice data does not have to be streamed to servers. This makes the module appropriate for outside, distant installations or sensitive settings by improving privacy, lowering dependence on network connectivity.
With its built-in microphone and speaker, the module enables rapid voice replies devoid of the requirement for additional audio apparatus. Using around 370 mA when at 5V, running at a voltage between 3.3V and 5V. With a small footprint of just about 49 x 32 mm, it qualifies for use in a lot of DIY projects, robotic activities, and smart home equipment. Stock contains two types: V1.0 (released March 2023) and V1.1 (released May 2025). The primary changes are in physical connectors: V1.1 provides an easier plug-and-play speaker connector (instead of a soldered one in V1.0) and more mounting holes more secure attachment on the board. Functionality is otherwise equivalent.
The Gravity Offline Speech Recognition Module supports multiple platforms, making it easy for both beginners and experienced developers. DFRobot offers an official library with sample code for Arduino users to rapidly test built-in and bespoke voice commands. Via typical I2C or UART communication, the module also interfaces with ESP32 boards; developers can integrate using either the Arduino IDE or ESP-IDF. For educational purposes, the Mind+ graphical programming interface supports the micro:bit, enabling pupils to include voice control with basic drag-and-drop components. Because the module operates totally offline, there is no need for complicated SDKs or cloud services, hence simplifying the software configuration and easy.
As of now, the Gravity Offline Speech Recognition Sensor is available in two versions: V1.0 (original release) and V1.1 (newer board with plug-and-play speaker connector and mounting holes). The price is typically around $29.90 USD for each version. Both models are currently offered through DFRobot’s official store, and they also appear on distributors like Amazon, Digi-Key and Mouser, depending on stock.
Sayantan Nandy