DHT22 with Arduino Mega 2560 R3

Wiring for the DHT22 (AM2302) temperature + humidity on the Arduino Mega 2560 R3 (ATmega2560, 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

DHT22 pin	Role	Arduino Mega 2560 R3 pin	Notes
VCC	Power	5V
DATA	One-wire data	22 (PA0)	Needs a 10 kΩ pull-up (included on 3-pin modules)
GND	Ground	GND

Check before you power it on

Supply: 5 V from the 5V pin.

Test code (Arduino)

// Library: DHT sensor library (Adafruit)
#include <DHT.h>

DHT dht(22, DHT22);

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

void loop() {
  delay(2000);  // the DHT22 needs 2 s between readings
  Serial.print(dht.readTemperature());
  Serial.print(" C  ");
  Serial.print(dht.readHumidity());
  Serial.println(" %");
}

Arduino board: arduino:avr:mega.

Questions

Which Arduino Mega 2560 R3 pins do I use for the DHT22?

VCC → 5V, DATA → 22 (PA0), GND → GND.

Does the DHT22 work with the Arduino Mega 2560 R3 at 5 V?

Yes: the DHT22 runs at 3.3-5 V and the Arduino Mega 2560 R3 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 Mega 2560 R3 pinout · DHT22 (AM2302) temperature + humidity: all pins and data

The DHT22 on other boards

ESP32 DevKit Arduino Nano Arduino Uno R3 WeAct Black Pill STM32F411CE ESP32-C3-DevKitM-1 ESP32-S3-DevKitC-1 Nordic nRF52840 DK NUCLEO-F401RE Raspberry Pi Pico 2 Raspberry Pi Pico W Raspberry Pi Pico Teensy 4.1

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