I am new to the Arduino platform. we were working on a project to measure the audio pollution levels. we want to make a real-time map of audio pollution levels throughout the city.
There are 100 interest points in the city to monitor audio pollution.
so I am planning to use a nodemcu for this. because the city already has wifi network we can connect to that. I am planning to use Firebase real-time database to store collected data from the device
I need your help regarding how should we measure the audio pollution in a small area. and what sensors we should use for this. and is it okay to connect each device for wifi directly or we do need another device as a master, and other device talk to that and that master device send data to firebase. and also I need to know how we power this unit. because we need to create this device smaller as we can. so we can install this outdoors easily
do a web search for arduino sound level you should get some useful links to sensors etc
are you sure the city WiFi network works in outside areas? do some tests?
if you have good WiFi coverage each NodeMCU (ESP32 or ESP8266?) should be able to communicate with Firebase
if WiFi is not dependable an alternative may be LoRaWAN
It has the advantage over other cheap sound sensors, in that it does it's own logarithmic conversion to give an analogue output that can be scaled in dBA.