Sound sensor try #1

After determining which sound sensors should be used for the TweetyBot project, I’ve just tried to get a peak detectorworking. It should be easy to built it, but it’s not. After spending most of the sunday time on it, nothing is working…

This peak detector is quite simple:

1. a LM386 acts as a preamp for the electret microphone
2. a first part of a (hard-to-find and expensive) OPA2277-PA handles adjustment of the sensitivity
3. another part of a (hard-to-find and expensive) OPA2277-PA handles comparisons and triggers the output level: 0V means “no sound”, +5V means “hey I got a sound”.

If I can get something from the LM386 output (tested with a multimeter and SirProbe), nothing from the OPA2277 output. I think this sensor must be build on a real board to avoid any contact failure, and tested with a real oscilloscope…