The Microphone Sound Input Module provides both audio-waveform and sound pressure level outputs with an inbuilt preamplifier.
Module Pinout
GND: Connect to GND (0V) on your microcontroller.
Mic Output: Provides amplified raw audio waveform. Connect to an analog input on your microcontroller if you want to process the audio signal.
SPL Output: Provides amplified sound pressure level (SPL). Connect to an analog input on your microcontroller if you want to process the SPL signal.
VCC: Connect to 5V on your microcontroller.
Measuring SPL
The SPL (Sound Pressure Level) output provides a voltage proportional to the audio level currently being detected. The SPL is also displayed visually using the "DETECT" LED near the top right of the module.
Connect the GND and VCC headers to your microcontroller as appropriate, and connect the SPL output to an analog input. In this example we've connected it to A0. The Mic output doesn't need to be connected for this application.
The following sketch reads the SPL value from the Microphone Sound Input Module five times per second and outputs it to the serial console in the Arduino IDE.
const int splSensor = A0; // the SPL output is connected to analog pin 0 void setup() { Serial.begin(38400); } void loop() { Serial.println(analogRead(splSensor), DEC); delay(200); // delay to avoid overloading the serial port buffer }
Copy and paste the code above into the Arduino IDE, upload it to your Arduino, and open the serial console at 38400bps. You will see a stream of readings scroll down the console showing the current sound pressure level.
