Well, that was stupid and annoying. The LM386 based sound level board arrived, duly tested and I started installing it. First mistake was buying a module, the second was trying to take the pin-header off it so it fit nicely...
One of the pins came out smoothly gripped in a pair of pliers and heated well. Great!
The other two ripped the pads and some track off the top layer. Not so great. I tried to repair them and got it working again, the LED lit when there was enough sound but the ADC output read high the entire time.
I found a common circuit floating around internet land holding a trusty C2N3904 I always seem to have laying around.
Seems easy enough. The rest of the components I have tucked away in labelled bags in strips of ten, caps and resistors. OK then.
Now here's where it gets arty lol. Yep, thats a train ticket lol. Normally stations arent very well manned and I wouldnt have that, the ticket barrier snarfs it to let me out. But under the current circumstances, with masks being mandatory on trains and shortly in shops, finally lol, these things are going to be fashionable. The staff enforce it pretty well, but little village stations are what they are and I just walked out with it while the ticket attendant was busy disinfecting the signage.
I see Dior are making noises about making their own brand. :-)
I laid down some Kapton, and dropped the copper tape on by eye using the plan as a reference. Close enough, then I put a bit of sellotape on top just to make sure they didnt slide about when the glue got warm.
That didnt take long, but I did start it at midnight lol, so I'll test it tomorrow...