Hi, I would like to start up a project for logging outdoor noise from nearby airport.
I think HA would be a good place for me to start logging this kind of data.
BUT I am unsure how to start it up. Have looked around in here and elsewhere not finding other that has already made something like that.
Plan is to setup some outside Digital Sound Noise Level Meter Decibel Logger of some sort but one that is smarthome enabled to some degree and not to expensive for common folks.
I imagine jet engines produce a lot of low frequency sounds, a lot of ot lower than human hearing threshold, but can still be measured with the correct equipment.
Once you are making reasonable measurements, I would then work on automating the process.
Well, that was also my first idea: A microphone with MAX4466 or LM393 amp, connected to an ESP running ESPHome. While measuring the analogue value works in principle, I don’t think that an ESP is suitable for continuously measuring the noise level, because it does other time critical things, in particular Wifi.
I was more thinking of connecting a microphone to an Arduino (or Teensy) microcontroller and let it do the heavy lifting, measuring the analogue value, processing and aggregating the data, and then use an ESP with ESPHome to collect the aggregated data and send it to HA.
That’s kind of the approach that the noise measurement sensor described on the luftdaten.info website is taking.
I’m pretty sure an ESP can handle a single analog input and transmitting that data to HA without any issue. That’s not exactly heavy lifting. HA would be doing the main data handling / calculations / storage. I’ve had an ESP8266 reading an analog input as well as controlling 3 outputs without trouble. There are likely many ways to do this, I was just going with a cheap and easy idea that I know works well with HA
Yeah, I agree that taking a single measurement from an analogue sensor is not considered “heavy lifting”.
However, let’s say you want to cover a frequency spectrum of 20 - 20,000Hz, then you may want to go with the standard 44.1kHz sample rate, i.e. 44100 samples per second or 1 sample every ~22µs. And this is the area where I am unsure if an ESP is the right choice for the job.
I have to admit, I was originally thinking about am ambient noise sensor that consists of 4 or 6 microphones for a 360Âş coverage which would put even more pressure on the microcontroller, so this may have driven me thinking that an ESP may not be enough for this challenge.
