sensors / ds18b20.md

DS18B20

Maxim/ADI's Dallas 1-Wire digital temperature sensor. ±0.5 °C accuracy over -10 to 85 °C. Each chip has a unique 64-bit ID — you can hang many sensors on one wire. Waterproof probe and TO-92 bare versions are common.

In stock Analog Devices

Specs

Spec	Value
Temp range	-55 to +125 °C
Accuracy	±0.5 °C (-10 to +85 °C)
Resolution	9 / 10 / 11 / 12-bit (configurable)
Conversion time	750 ms @ 12-bit
Bus	1-Wire (Dallas)
Power	3.0–5.5 V or parasite mode
Pinout (TO-92, flat side facing)	GND, DQ, VDD

Wiring (Arduino Uno, one sensor)

DS18B20	Arduino
GND	GND
DQ	D2
VDD	5 V
Pull-up	4.7 kΩ between DQ and VDD

Waterproof probe colors:

Wire	DS18B20 pin
Red	VDD
Yellow / White	DQ
Black / Blue	GND

Code

#include <OneWire.h>
#include <DallasTemperature.h>

OneWire bus(2);
DallasTemperature sensors(&bus);

void setup() {
  Serial.begin(9600);
  sensors.begin();
}
void loop() {
  sensors.requestTemperatures();
  Serial.print(sensors.getTempCByIndex(0)); Serial.println(" °C");
  delay(1000);
}

Libraries: OneWire + DallasTemperature (Library Manager).

Schematic

Internal block diagram and application circuit on page 1 + page 19 of the datasheet PDF.

Last updated: 2026-05-13 · Source on GitHub