Grove - Loudness Sensor

The Grove - Loudness Sensor is designed to detect the sound of environment. Based on LM2904 amplifier and a built-in microphone, it amplifies and filters the high frequency signal that received from the microphone, and outputs a positive envelop. This is used for Arduino’s signal acquisition. The output value depends on the level of sound input. In order to avoid unnecessary signal disturbances, input signal will go through two times’ filtering inside the module. There is a screw potentiometer that enables manual adjustments to the output gain.


Product Version Changes Released Date
Grove-Loudness Sensor V0.9b Initial Dec 2012


  • Grove Interface
  • Easy to use
  • Basic Grove element


More details about Grove modules please refer to Grove System


Parameter Value/Range
Voltage 3.5~10 VDC
Working Frequency 50~2000 Hz
Sensitivity -48~66 dB
Signal-to-noise Ratio >58 dB
Output Signal range Analog Signal (0-1023)

Platforms Supported

Arduino Raspberry Pi BeagleBone Wio LinkIt ONE


The platforms mentioned above as supported is/are an indication of the module's hardware or theoritical compatibility. We only provide software library or code examples for Arduino platform in most cases. It is not possible to provide software library / demo code for all possible MCU platforms. Hence, users have to write their own software library.

Getting Started


If this is the first time you work with Arduino, we firmly recommend you to see Getting Started with Arduino before the start.

Play With Arduino


  • Step 1. Prepare the below stuffs:
Seeeduino V4.2 Base Shield Grove-Loudness Sensor
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  • Step 2. Connect Grove-Loudness Sensor to A0 port of Grove-Base Shield.
  • Step 3. Plug Grove - Base Shield into Seeeduino.
  • Step 4. Connect Seeeduino to PC via a USB cable.


If we don't have Grove Base Shield, We also can directly connect Grove-Loudness Sensor to Seeeduino as below.

Seeeduino Grove-Loudness Sensor
5V Red
GND Black
NC White
A0 Yellow


  • Step 1. Please copy below code to Arduio IDE and upload to arduino. If you do not know how to upload the code, please check how to upload code.
int loudness;

void setup()

void loop()
    loudness = analogRead(0);
  • Step 2. Open the serial to monitor the output. It will be a significant change when blow to the sensor.

Play With Raspberry Pi


  • Step 1. Prepare the below stuffs:
Raspberry pi GrovePi_Plus Grove-Loudness Sensor
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  • Step 2. Plug the GrovePi_Plus into Raspberry.
  • Step 3. Connect Grove-Loudness Sensor to A0 port of GrovePi_Plus.
  • Step 4. Connect the Raspberry to PC through USB cable.


  • Step 1. Follow Setting Software to configure the development environment.
  • Step 2. Git clone the Github repository.
cd ~
git clone https://github.com/DexterInd/GrovePi.git
  • Step 3. Excute below commands to monitor the loudness.
cd ~/GrovePi/Software/Python
python grove_loudness_sensor.py

Here is the grove_loudness_sensor.py code.

import time
import grovepi

# Connect the Grove Loudness Sensor to analog port A0
loudness_sensor = 0

while True:
        # Read the sound level
        sensor_value = grovepi.analogRead(loudness_sensor)

        print("sensor_value = %d" %sensor_value)

    except IOError:
        print ("Error")
  • Step 4. We will see the loudness status as below.
pi@raspberrypi:~/GrovePi/Software/Python $ python grove_loudness_sensor.py
sensor_value = 135
sensor_value = 23
sensor_value = 196
sensor_value = 258
sensor_value = 98
sensor_value = 131


  • Q1: What is the difference between Grove-Loudness sensor and Grove - Sound Sensor?
    • A1: The Grove-Loudness sensor have screw potentiometer to adjust the output gain.


Tech Support

Please do not hesitate to contact techsupport@seeed.cc if you have any technical issue. Or submit the issue into our forum.