NoiseMeter
| Project NoiseMeter | |
|---|---|
| File:NoiseMeter.jpg | |
| Measuring audio noise as citizen science | |
| Status | Initializing |
| Contact | bertrik |
| Last Update | 2023-11-03 |
Introduction
This project is about measuring environmental audio noise as citizen science.
For example, noise can be:
- road traffic noise (cars, mopeds, etc)
- air traffic noise,
- industrial noise, like building activities
Existing sound/noise meter projects:
- DNMS project by Helmut Bitter
- LoRa sound kit by Marcel Meek, ESP32 with I2S microphone, shares many concepts with EspAudioSensor
- LoRaWAN PM/Sound sensor by Bas van Drunen, shares many concepts with LoraWanDustSensor
- Amsterdam sounds kit from Waag Society,
- Unknown sensor tested by RIVM in Schiedam (mentioned on https://www.samenmetenaanluchtkwaliteit.nl/nieuws/citizen-science-geluidmetertest-op-rivm-terrein )
- Sound meter by Bart Jurgens uit Amerongen, link ???
This project page considers a kind of clone of the Amsterdam Sounds project.
Hardware
Nano33 IOT
Hardware is a nano33 iot board.
| SPH0645 | nano33 iot | Remark |
|---|---|---|
| SEL | - | leave unconnected |
| LRCK | A2 (16) - I2S FS | sample clock |
| DOUT | D4 (4) - I2S SD | data |
| BCLK | A3 (17) - I2S SCK | bit clock |
| GND | GND | |
| 3V | 3v3 |
Software
The software is based on Arduino, a kind of clone of the Amsterdam Sounds project, modified to use WiFi (instead of LoRa), written by Rene Kuijf.
My modifications consist of a platformio configuration, for easy building.
See AdamSoundsInflux-slim-nano-33 github repo for the source code.
Casing
Microphone protection
To protect the microphone, use a membrane, like:
Junction box
Simple junction boxes sold by Gamma:
- https://www.gamma.nl/assortiment/attema-kabeldoos-m20-met-3-wartels-ip65/p/B410376 and
- https://www.gamma.nl/assortiment/attema-kabeldoos-ip65-3x-m25-m20/p/B306878 (IP65)
A downward pointing hole can be used for an 868 MHz LoRaWAN antenna.
Sensor.community casing
See https://sensor.community/docs/dnms/dnms-noise-measuring-dn40-result.jpg
Dimensions:
- microphone is on a half inch (12.7 mm OD) white polystyrene pipe, 115 mm long
- main piece is 25mm, length 160mm
- some other connecting piecess
"RIVM" test casing
Exact dimensions unknown, see photo on this page: https://samenmeten.nl/nieuws/citizen-science-geluidmetertest-op-rivm-terrein
My guess:
- microphone is on a 10mm diameter pipe, length 100mm
- main case is a 40mm diameter pipe, length 200mm