So, this project has been a put on a shelf for a while, but what’s happened in 4 years?
Several things–most notably we’ve moved out further into the suburbs, and the loud sounds seem to have mostly abated. Whereas at the old place, I was pretty much guaranteed a loud sound every few days, but here I’m limited to a few clusters of booms around the 4th of July and New Year’s Eve, with very little else in the way of sample data. I don’t think my new neighbors would appreciate my setting off fireworks just to have sample data. I like to tell myself that the sounds at the old place were fireworks, but the reality was more likely a mixture of gunshots and fireworks.
Second, I’ve just lost steam on this. The problems with getting the timing right and other things like that have convinced me that maybe I need to re-think the microphone design. I’m thinking of using a dedicated GPS module on each microphone unit to establish both location and time more accurately, but that pushes up the cost considerably. GNSS/GPS receivers can be had for $30 or $35 dollars on convenient breakout boards, but that nearly doubles the cost per microphone. At that point maybe I should consider using a Raspberry Pi Zero 2W or similar, though the lack of analog inputs is problematic.