seeed studio Grove Loudness Sensor User manual

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.
Version
Product Version Changes Released Date
Grove-Loudness Sensor V0.9b Initial Dec 2012
Features
Grove Interface
Easy to use
Basic Grove element
…
Tip
whatshot
Sound / Grove / Grove - Loudness Sensor

Specifications
Parameter Value/Range
Voltage 3.5~10 VDC
Working Frequency 5~2000 Hz
Sensitivity -60~-56dBV/Pa
Signal-to-noise Ratio >58 dB
Output Signal range Analog Signal (0-
1023)
Platforms Supported
Arduino Raspberry Pi
Getting Started
Play With Arduino
Hardware
Step 1. Prepare the below stuffs:
Seeeduino V4.2 Base Shield Grove-Loudness Sensor
Get One Now Get One Now Get One Now
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.
More details about Grove modules please refer to Grove System
Caution
The platforms mentioned above as supported is/are an indication of the module's software 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.
warning
Note
If this is the first time you work with Arduino, we firmly recommend you to see Getting Started with
Arduino before the start.
edit

Seeeduino Grove-Loudness Sensor
5V Red
GND Black
NC White
A0 Yellow
Software
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 .
Step 2. Open the serial to monitor the output. It will be a significant change when blow to
the sensor.
Play With Raspberry Pi (With Grove Base Hat for Raspberry Pi)
Hardware
Step 1. Things used in this project:
Note
If we don't have Grove Base Shield, We also can directly connect Grove-Loudness Sensor to Seeeduino
as below.
edit
int loudness;
void setup()
{
Serial.begin(9600);
}
void loop()
{
loudness = analogRead(0);
Serial.println(loudness);
delay(200);
}

Raspberry pi Grove Base Hat for RasPi Grove - Loudness Sensor
Get ONE Now Get ONE Now Get ONE Now
Step 2. Plug the Grove Base Hat into Raspberry Pi.
Step 3. Connect the Grove - Loudness Sensor to to the A0 port of the Base Hat.
Step 4. Connect the Raspberry Pi to PC through USB cable.
Software
Step 1. Follow Setting Software to configure the development environment.
Step 2. Download the source file by cloning the grove.py library.
Step 3. Excute below command to run the code.
Following is the grove_water_sensor.py code.
cd ~
git clone https://github.com/Seeed-Studio/grove.py
cd grove.py/grove
python grove_loudness_sensor.py 0

You can use this sensor to detect the loudness. Press Ctrl +C to quit.
Play With Raspberry Pi(with GrovePi_Plus)
Hardware
Step 1. Prepare the below stuffs:
Raspberry pi GrovePi_Plus Grove-Loudness Sensor
Get One Now Get One Now Get One Now
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.
import math
import sys
import time
from grove.adc import ADC
class GroveLoudnessSensor:
def __init__(self, channel):
self.channel = channel
self.adc = ADC()
@property
def value(self):
return self.adc.read(self.channel)
Grove = GroveLoudnessSensor
def main():
if len(sys.argv) < 2:
print('Usage: {} adc_channel'.format(sys.argv[0]))
sys.exit(1)
sensor = GroveLoudnessSensor(int(sys.argv[1]))
print('Detecting loud...')
while True:
value = sensor.value
if value > 10:
print("Loud value {}, Loud Detected.".format(value))
time.sleep(.5)
if __name__ == '__main__':
main()
Success
If everything goes well, you will be able to see the following result:
done
pi@raspberrypi:~/grove.py/grove $ python grove_loudness_sensor.py 0
Detecting loud...
Loud value 15, Loud Detected.
Loud value 11, Loud Detected.
Loud value 250, Loud Detected.
Loud value 429, Loud Detected.
Loud value 203, Loud Detected.
Loud value 16, Loud Detected.
Loud value 11, Loud Detected.
^CTraceback (most recent call last):
File "grove_loudness_sensor.py", line 68, in <module>
main()
File "grove_loudness_sensor.py", line 65, in main
time.sleep(.5)
KeyboardInterrupt
Notice
You may have noticed that for the analog port, the silkscreen pin number is something like A1, A0,
however in the command we use parameter 0 and 1, just the same as digital port. So please make sure
you plug the module into the correct port, otherwise there may be pin conflicts.
edit

Software
Step 1. Follow Setting Software to configure the development environment.
Step 2. Git clone the Github repository.
Step 3. Excute below commands to monitor the loudness.
Here is the grove_loudness_sensor.py code.
Step 4. We will see the loudness status as below.
FAQ
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.
Schematic Online Viewer
cd ~
git clone https://github.com/DexterInd/GrovePi.git
cd ~/GrovePi/Software/Python
python grove_loudness_sensor.py
import time
import grovepi
# Connect the Grove Loudness Sensor to analog port A0
# SIG,NC,VCC,GND
loudness_sensor = 0
while True:
try:
# Read the sound level
sensor_value = grovepi.analogRead(loudness_sensor)
print("sensor_value = %d" %sensor_value)
time.sleep(.5)
except IOError:
print ("Error")
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

Resources
[Eagle&PDF] Grove - Loudness Sensor Schematic
[Datasheet] LM2904DR Datasheet