Noise Detection Ruby Script.
Send email if noise is detected.
The noise dector ruby script uses two linux tool to record and analyse de output: sox and arecord. So you need to install these packages on your raspberrypi (or other linux system):
sudo apt-get install sox alsa-utils
Then, in the current version, the script does not accept parameters to change file location (log, tmp recording and pid file), so you need to allow the script execution user (pi for example) the write access to these files and folders:
RECORD_FILENAME='/tmp/noise.wav'
LOG_FILE='/var/log/noise_detector.log'
PID_FILE='/etc/noised/noised.pid'
or you can edit the script changin these variables values with what you prefer for your system.
pi@raspberrypi ~ $ noise_detection.rb -d
Detecting your soundcard...
0 [ALSA ]: BRCM bcm2835 ALSbcm2835 ALSA - bcm2835 ALSA
bcm2835 ALSA
1 [U0x46d0x8d7 ]: USB-Audio - USB Device 0x46d:0x8d7
USB Device 0x46d:0x8d7 at usb-bcm2708_usb-1.2, full speed
pi@raspberrypi ~ $ noise_detection.rb -t 1
Testing soundcard...
Samples read: 40000
Length (seconds): 5.000000
Scaled by: 2147483647.0
Maximum amplitude: 0.013245
Minimum amplitude: -0.041565
Midline amplitude: -0.014160
Mean norm: 0.013523
Mean amplitude: -0.013466
RMS amplitude: 0.014662
Maximum delta: 0.023560
Minimum delta: 0.000000
Mean delta: 0.003664
RMS delta: 0.004679
Rough frequency: 406
Volume adjustment: 24.059
noise_detection.rb -m 1 -n 0.30 -e me@server.com -v
The script will be started in background
noise_detection.rb -k