Rain sensor module (FC-37 / YL-83) with ESP32

Supply 3.3-5 V Bus ANALOG Measures rain
VCCGNDDOAO

Pins and ESP32 wiring

PinRoleESP32 pinNotes
VCCPower3V3Use 3V3 so AO stays within the ADC range
GNDGroundGND
DOOutput (the part drives it)D25LOW when rain is detected (threshold set with the trimmer)
AOAnalog outputD34Lower voltage means more water. To an ADC pin (prefer ADC1: GPIO 32 to 39)

Suggested wiring for the 30-pin ESP32 DevKit, avoiding flash, input-only and strapping pins. BoardPilot checks it for you as you wire.

Starter code (Arduino)

void setup() { Serial.begin(115200); }

void loop() {
  int mv = analogReadMilliVolts(34);  // AO on GPIO 34
  Serial.println(mv);
  delay(200);
}

Sources

Try it in 3D in BoardPilot

BoardPilot Part data (JSON)

Related parts

Part data: CC BY 4.0, free to reuse with credit to BoardPilot.