ESP32 Forum

Hello,
I have an Pulse-Source, which switches between 0 and 5 V. I want to connect it to an ESP32 GPIO, configured as digial Input. I know, the input Voltage should not exeed 3.3 V. I ask, whether an series- resistor between 5V-Source and ESP32 input can reduce the current and voltage to a level, which is not dangerous for the ESP32? The maximum switching frequency ist below 15 kHz. I hope, that the Inputs have some protection circuits.
Thank You!
MicroLove#22

The easy ways to do this are basically:

1. Resistor + schottky diode to 3.3 V Vcc
2. Voltage divider (two resistors)
3. 74HC/AC/AHC buffer (3 3 V Vcc)
4. 74CB3T/CBDT/CBT bus switch (in order of preference); these are bidirectional and almost zero latency!