HC-SR501 PIR with Arduino Nano

Wiring for the HC-SR501 PIR motion sensor on the Arduino Nano (ATmega328P, 5 V logic), chosen with the same pin rules BoardPilot uses: default buses first, and no pins that are used for flash, USB, the debugger or booting.

Wiring

HC-SR501 PIR pinRoleArduino Nano pinNotes
VCCPower5VNeeds 4.5 V or more: use 5V
OUTOutput from the partD2 (PD2)
GNDGroundGND

Check before you power it on

Test code (Arduino)

void setup() {
  Serial.begin(115200);
  pinMode(2, INPUT);  // OUT on D2
}

void loop() {
  Serial.println(digitalRead(2));
  delay(100);
}

Arduino board: arduino:avr:nano. Clones with the old bootloader upload at 57600 baud: choose “ATmega328P (Old Bootloader)” if uploads fail.

Questions

Which Arduino Nano pins do I use for the HC-SR501 PIR?

VCC → 5V, OUT → D2 (PD2), GND → GND.

Does the HC-SR501 PIR work with the Arduino Nano at 5 V?

Yes: the HC-SR501 PIR runs at 5 V and the Arduino Nano uses 5 V signals, so no level shifting is needed.

BoardPilot checks this wiring in 3D as you build it, and finds crossed or missing wires on the real board.

Download BoardPilot

Full Arduino Nano pinout · HC-SR501 PIR motion sensor: all pins and data

The HC-SR501 PIR on other boards

Other parts on the Arduino Nano