Ok, so I have an application where I want to imitate a microphone like beeping or buzzing input, doesn't really matter, just need a general audio waveform without using an actual mic and audio input. I was thinking maybe with a low-voltage zener diode, capacitor, and resistor might do it, but I'm not educated enough to know how to do this. The next best option I can think of is using a cheap chip like a Seeeduino Xiao which has an analog output, so I could program some waveform on it and have it output that, but those are a few dollars, like $6, and the size of a quarter, so I'm hoping there's some simple, easy, cheap, compact way to get something like that. I've searched the web a bit but I couldn't find anything. I would imagine someone has done something like this, but I can't seem to find it.