Voice-controlled systems are becoming increasingly popular in smart devices, automation projects, and AI applications. But running speech recognition directly on a microcontroller is usually difficult because it requires heavy processing power. This ESP32 Speech to Text project solves that problem by combining the ESP32 development board with the Wit.ai cloud API.
In this project, an INMP441 I2S microphone captures your voice, the ESP32 sends the audio to Wit.ai through WiFi, and the recognised text is displayed on an OLED screen in real time. No complex AI model training or dedicated speech recognition hardware is required.
How the ESP32 Speech to Text System Works
The working principle of this project is simple and efficient. The INMP441 microphone records audio digitally using the I2S protocol. The ESP32 reads this audio and streams it to the Wit.ai cloud service over HTTPS.
Wit.ai processes the speech using Natural Language Processing (NLP) and returns the recognised text in JSON format. The ESP32 extracts the text and displays it on the OLED display as well as the Serial Monitor.
This makes the system work like a compact voice assistant:
- Press the button
- Speak into the microphone
- View the converted text instantly
Main Components Required
This ESP32 Speech Recognition project uses only a few components:
- ESP32 Development Board
- INMP441 I2S Microphone
- 0.91-inch OLED Display
- Push Button
- Breadboard and Jumper Wires
The ESP32 acts as the main controller, while the OLED display shows the recognised speech output in real time.
Why Use Wit.ai for ESP32 Speech Recognition?
One of the biggest advantages of this project is using Wit.ai instead of offline speech processing.
Benefits of Wit.ai:
- Free cloud-based speech recognition
- No AI model training required
- Supports multiple languages
- Easy API integration
- Works with low-cost ESP32 boards
Since all speech processing happens in the cloud, the ESP32 only handles audio capture and data transmission.
Hardware Connections
The INMP441 microphone connects to the ESP32 using the I2S interface:
- WS → GPIO 25
- SD → GPIO 33
- SCK → GPIO 26
The OLED display uses I2C communication:
- SDA → GPIO 21
- SCL → GPIO 22
A push button is connected to activate listening mode.
ESP32 Speech to Text Code Overview
The Arduino code handles:
- WiFi connection
- OLED display updates
- I2S microphone initialization
- HTTPS communication with Wit.ai
- JSON response parsing
When the button is pressed, the ESP32 continuously streams audio chunks to the Wit.ai API. Once the button is released, the API processes the speech and returns the recognised sentence.
The final text appears instantly on the OLED display.
Applications
This ESP32 Speech to Text system can be expanded into many advanced projects:
- Voice-controlled home automation
- Smart assistants
- Speech-controlled relays
- IoT dashboards with voice logging
- WhatsApp voice notifications
- Multi-language recognition systems
You can also combine this with Text-to-Speech projects to create a complete two-way voice interface.
Robotics Projects |Arduino Projects | Raspberry Pi Projects|
No comments:
Post a Comment