RCWL-0516 microwave motion radar with ESP32

Supply 5 V Bus GPIO Measures motion

Pins and ESP32 wiring

Pin	Role	ESP32 pin	Notes
3V3	Not wired to the ESP32	—	Output of the on-board regulator (100 mA max). Do not feed power here
GND	Ground	GND
OUT	Output (the part drives it)	D25	3.3 V HIGH for about 2 s after motion
VIN	Power	VIN	4 to 28 V: use VIN (5 V)
CDS	Not wired to the ESP32	—	Optional light sensor input. Leave unconnected

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

This module is sold for 5 V. Its outputs may be 5 V: use a level shifter or a voltage divider on ESP32 inputs.

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

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

RCWL-0516 module description (RCWL / jdesbonnet GitHub notes), Pins 3V3, GND, OUT, VIN, CDS; VIN 4 to 28 V; OUT 3.3 V

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