I need to make sure that 3.3V goes from the ECHO pin to my ESP8266 instead of 5V. I tried a bunch of different resistor voltage divider combinations and check the voltage on the ECHO vs Ground.
No matter what i did, the multimeter would bounce around between zero and 5…
I also tried Analogread (voltage). It did the same thing.
Without compromising my ESP8226, how can I ensure that my voltage divider has brought the ECHO voltage from 5v to 3.3v (or close)?
I dont have an oscilloscope.
Thanks in advance!