I want to give my bot ears but this unit does not seem to have much sensitivity. I put power to it and connected it to my scope and it showed a small sawtooth wave and, nothing else. The only response I could get out of it was to scratch my fingernail across the mic-this showed a square wave out, but, not shouting worked?
That sounds like the wrong behavior. Can you please tell us more about your wiring, power supply and post a picture?
Can you just try looking at the output on a scope without the picaxe or pulldown in the system? If it still doesn’t work, I suggest you try contacting the manufacturer, Sparkfun, directly for tech support.