DS18B20 with Arduino Uno R3

Wiring for the DS18B20 waterproof temperature probe on the Arduino Uno R3 (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

DS18B20 pin	Role	Arduino Uno R3 pin	Notes
VDD	Power	5V	Red wire
DQ	One-wire data	2 (PD2)	Yellow (sometimes white) wire. Needs a 4.7 kΩ pull-up to 3.3 V
GND	Ground	GND	Black wire

Check before you power it on

Supply: 5 V from the 5V pin.

Test code (Arduino)

// Library: OneWire, DallasTemperature
#include <OneWire.h>
#include <DallasTemperature.h>

OneWire bus(2);  // needs a 4.7 kΩ pull-up from DQ to VDD
DallasTemperature sensors(&bus);

void setup() {
  Serial.begin(115200);
  sensors.begin();
  Serial.print("Sensors found: ");
  Serial.println(sensors.getDeviceCount());
}

void loop() {
  sensors.requestTemperatures();
  Serial.println(sensors.getTempCByIndex(0));
  delay(1000);
}

Arduino board: arduino:avr:uno.

Questions

Which Arduino Uno R3 pins do I use for the DS18B20?

VDD → 5V, DQ → 2 (PD2), GND → GND.

Does the DS18B20 work with the Arduino Uno R3 at 5 V?

Yes: the DS18B20 runs at 3.3-5 V and the Arduino Uno 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 Uno R3 pinout · DS18B20 waterproof temperature probe: all pins and data

The DS18B20 on other boards

ESP32 DevKit Arduino Mega 2560 R3 Arduino Nano 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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