INMP441 Omnidirectional Microphone Module

The INMP441 is a digital omnidirectional microphone module based on MEMS (Micro-Electro-Mechanical Systems) technology. It provides high-quality audio input with a digital I2S output interface, making it ideal for sound and voice detection applications. The module is designed for use in microcontroller-based systems such as Arduino and Raspberry Pi, providing a simple and efficient way to integrate audio functionality into your projects.

Specifications

• Microphone Type: MEMS Omnidirectional Microphone
• Output: I2S (Digital Signal)
• Supply Voltage: 3.3V to 5V
• Sample Rate: Up to 50kHz
• Power Consumption: 3.3mA (typical)
• Signal-to-Noise Ratio: 65dB
• Sensitivity: -26dBFS
• Size: Compact, SMD Package

Pinout

The INMP441 module has the following pins:

• VCC: Power supply pin (3.3V to 5V)
• GND: Ground pin
• LRCL: Left/Right Clock signal for stereo (I2S)
• SCK: Serial Clock signal for I2S communication
• SD: Serial Data output (I2S data stream)

Applications

The INMP441 microphone module can be used in a wide range of applications, including:

• Voice Recognition: Capture and process sound for voice-controlled devices.
• Sound Detection: Detect noise levels or specific sound frequencies for monitoring systems.
• Sound-Based User Interaction: Create projects that respond to audio inputs, such as sound-triggered alarms or robots.
• Audio Recording: Record high-quality audio for various applications such as audio logging and sound analysis.

Key Features

• High-Quality Audio: MEMS microphone provides a high signal-to-noise ratio (SNR) of 65dB.
• Low Power Consumption: Consumes only 3.3mA (typical), making it ideal for battery-powered devices.
• Compact Size: The small SMD package allows easy integration into space-constrained applications.
• I2S Interface: Provides a digital output, simplifying integration with microcontrollers and avoiding the need for complex analog-to-digital conversion.
• Omnidirectional Sensitivity: Captures sound from all directions, making it suitable for environmental sound detection.

Wiring Diagram

Here's how to connect the INMP441 microphone module to an Arduino or Raspberry Pi:

        +------------------+   +------------------+
        |   INMP441 Module |   |   Arduino/RPi    |
        +------------------+   +------------------+
        |   VCC            |-------------------> 3.3V or 5V
        |   GND            |-------------------> GND
        |   LRCL           |-------------------> Pin for I2S Left/Right Clock
        |   SCK            |-------------------> Pin for I2S Serial Clock
        |   SD             |-------------------> Pin for I2S Data
        +------------------+   +------------------+
    

Sample Code (Arduino)

        // Include necessary libraries
        #include 
        #include 

        void setup() {
          // Initialize Serial communication for debugging
          Serial.begin(115200);
          
          // Initialize I2S communication for INMP441
          I2S.begin(I2S_PHILIPS_MODE, 16000, 16);
        }

        void loop() {
          int16_t sampleData = 0;
          
          // Read the audio data from INMP441 (I2S)
          if (I2S.available()) {
            sampleData = I2S.read();
            Serial.println(sampleData); // Print raw audio data to Serial Monitor
          }
          
          delay(10); // Delay for stability
        }
    

Installation Tips

• Ensure that the VCC pin is connected to a 3.3V or 5V power source depending on your microcontroller's voltage.
• Use the I2S interface to read data from the microphone, which simplifies the process of working with digital audio.
• For best performance, use a low-pass filter to smooth out the audio signal if needed, particularly for higher-fidelity applications.