IR break-beam sensor pair (emitter + receiver) with ESP32

Supply 3.3-5 V Bus GPIO Measures presence

Pins and ESP32 wiring

Pin	Role	ESP32 pin	Notes
TX-VCC	Power	3V3	Emitter red wire
TX-GND	Ground	GND	Emitter black wire
RX-VCC	Power	3V3	Receiver red wire
RX-GND	Ground	GND	Receiver black wire
OUT	Output (the part drives it)	D25	Receiver white wire. Open collector: use INPUT_PULLUP. LOW when the beam is unbroken

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

void setup() {
  Serial.begin(115200);
  pinMode(25, INPUT);  // OUT
}

void loop() {
  Serial.println(digitalRead(25));
  delay(100);
}

Adafruit IR Break Beam Sensors guide, Receiver output is open collector and needs a pull-up; 3.3 to 5 V supply

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