RCWL-0516 with an ESP32 DevKit V1
RCWL-0516 is a low-cost microwave Doppler radar motion sensor that outputs a simple digital HIGH when it detects movement, with no infrared optics required.
The RCWL-0516 takes the ESP32 DevKit V1's VIN on its own VIN pin, inside its 4 V to 28 V range, and its OUT drives GPIO13 directly. OUT is a 3.3 V signal from the module's own regulator, so it needs no level shifting on this board.
Wiring the RCWL-0516 to the ESP32 DevKit V1
Pin by pin.
| RCWL-0516 | ESP32 DevKit V1 |
|---|---|
| VIN | VIN |
| OUT | GPIO13 (D13) |
| GND | GND |
- VIN is on VIN, which gives about 5 V only while the board is powered from USB.
What to know on the ESP32 DevKit V1
- OUT goes high at 3.3 V for about 2 s on motion, a level the ESP32 reads directly. Leave the module's 3V3 pin unconnected: it is an output.SparkFun RCWL-0516 product specifications
- GPIO13 is also RTC_GPIO14, and RTC GPIOs keep working in deep sleep and can wake the chip. A battery ESP32 can sleep until OUT goes high, instead of polling it every 200 ms like the sketch.Espressif ESP32 Series Datasheet v5.3, p. 14; Espressif ESP32 Series Datasheet v5.3, p. 61
- On USB, VIN carries about 5 V. On a battery build the module can take the battery directly, since it accepts up to 28 V and draws about 2.7 mA.SparkFun RCWL-0516 product specifications
RCWL-0516 code for the ESP32 DevKit V1
Compiled for esp32:esp32:esp32 on 2026-10-29.
// RCWL-0516 on ESP32 DevKit V1: wiring and a free simulation at https://www.tinkered.ai/components/rcwl-0516/esp32
const int RADAR_OUT = 13; // RCWL-0516 OUT
void setup() {
Serial.begin(9600);
pinMode(RADAR_OUT, INPUT);
}
void loop() {
int motion = digitalRead(RADAR_OUT);
Serial.println(motion == HIGH ? "Motion detected" : "No motion");
delay(200);
}
RCWL-0516 on the ESP32 DevKit V1: questions
Do I need a level shifter between the RCWL-0516 and an ESP32?
No. OUT drives to 3.3 V (SparkFun specifications), the ESP32's own logic level.
Can the RCWL-0516 wake an ESP32 from deep sleep?
Yes, on an RTC GPIO such as GPIO13 (RTC_GPIO14, ESP32 datasheet p. 14): RTC GPIOs can wake the chip from deep sleep (p. 61). Configure an ext0 wake-up on a high level.
Keep going
This guide as plain Markdown. /components/rcwl-0516/esp32.md