ESP32 Forum

Hello, i was seeing some tutorials for using HC-SR04 with ESP32 and they was using a 5V battery to power up HC-SR04, so echo pin should send 5V too, but i was reading that ESP32 should use up to 3.9V , so i am a little confuse about why is that?, could i use ESP32 with sensor and drivers that work with 5V?. Thz

It's because the ESP32 itself works at 3.3V; it can tolerate voltages slightly higher than normal but not that much. In your case, I'd use a resistive divider (say 10K/4.7K) to get the voltage in range of the ESP32 I/O pins.

Thank you for your answer