I am trying to power an ESP8266 with a 3.3V regulator (this one, can supply ~ 1A). I've been struggling for days to get the ESP to work – it will occasionally boot, occasionally connect, but then not work again for hours. What I mean by "not working" is that it will often have trouble communicating over UART; or, upload my code, but not run it; or, run my code and crash on an Exception 0.
Now I have noticed that my voltage rail is dipping severely, sometimes below 3V. If I press my reset button, the level returns to 3.3V, but then when the ESP "boots" (but often not running any code, or crashing), it dips back to 2.9V. It is also fine while programming.
Does this suggest my ESP is simply fried? It's possible I briefly misconnected a wire when I first got the unit.