BakeBit - Sound Sensor

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Introduction

Sound Sensor
  • The BakeBit - Sound Sensor is a sound detection module. The module contains an electret condenser microphone. Sound waves impinging on the diaphragm cause the capacitance between it and the back plate to change synchronously, this in turn induces an AC voltage on the back plate, which is amplified with LM358 as output.
  • Its default output is high. When it detects a sound wave it will output low. When no sounds are detected it will output high.

Hardware Spec

  • Standard 2.0mm 4-Pin BakeBit Interface

BakeBit - Sound Sensor

  • Pin Description:
Pin Description
GND Ground
5V 5V Supply Voltage
NC Not Connected
SIG Signal

Code Sample:Sound Sensor

When this program runs if surrounding environment’s sounds reach a threshold value the LED will be turned on.

Hardware Setup

Connect the Sound Sensor module to the NanoHat Hub's A0 and the LED module to the NanoHat Hub's D5:

Sound Sensor-1.jpg Sound Sensor-2.jpg

Source Code

import time
import bakebit
 
# Connect the BakeBit Sound Sensor to analog port A0
# SIG,NC,VCC,GND
sound_sensor = 0
 
# Connect the BakeBit LED to digital port D5
# SIG,NC,VCC,GND
led = 5
 
bakebit.pinMode(sound_sensor,"INPUT")
bakebit.pinMode(led,"OUTPUT")
 
# The threshold to turn the led on 400.00 * 5 / 1024 = 1.95v
threshold_value = 400
 
while True:
    try:
        # Read the sound level
        sensor_value = bakebit.analogRead(sound_sensor)
 
        # If loud, illuminate LED, otherwise dim
        if sensor_value > threshold_value:
            bakebit.digitalWrite(led,1)
        else:
            bakebit.digitalWrite(led,0)
 
        print("sensor_value = %d" %sensor_value)
        time.sleep(.2)
 
    except IOError:
        print ("Error")

Github


Run Code Sample

Before you run the code sample you need to follow the steps in bakebit tutorial to install the BakeBit package.
Enter the "BakeBit/Software/Python" directory and run the "bakebit_sound_sensor.py" program:

cd ~/BakeBit/Software/Python
sudo python bakebit_sound_sensor.py

Observation

When you make some sounds to the sound sensor and if the sounds are big enough the LED will be turned on.

Resources

Update Log

December-14-2016

  • Released English version

Jan-19-2017

  • Renamed "NEO-Hub" to "NanoHat-Hub"

Jan-20-2017

  • Renamed "NanoHat-Hub" to "NanoHat Hub"