Thanks for the suggestions. Unfortunately, I do not have a valid reference voltage available. I did some further measurements. measurementcycle-1.png shows the drop in input voltage with each measurement cycle of my ESP32 application. This is the minimum hysteresis that is needed (about 0.5 V, 0.65 ...

I have a ESP32-based project that is powered by a hub dynamo of a bike and gets its VCC at 3.4V and has a 1000 uF capacitor as a buffer (Eagle sketch at https://github.com/mh-g/esp32-speedometer-proto-hw). However, the system does not start up reliably. I suspect the ESP32 starting when the voltage ...