Introduction

The DS18B20 is a digital temperature sensor with ±0.5°C accuracy over the range of -10°C to +85°C. It uses the 1-Wire communication protocol, allowing multiple sensors to be connected on a single data line.

Key Features

Technical Specifications

Pin Configuration

Wiring Diagrams

// Connections:
// VDD → 3.3V/5V
// DQ  → Digital Pin (with 4.7KΩ pull-up to VDD)
// GND → GND

// Connections:
// VDD → GND
// DQ  → Digital Pin (with 4.7KΩ pull-up to 3.3V/5V)
// GND → GND

Library Setup

1. Install the OneWire and DallasTemperature libraries
2. Include the required libraries:

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

3. Initialize the sensor:

#define ONE_WIRE_BUS 2 // Data wire connected to digital pin 2

OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

void setup() {
  Serial.begin(9600);
  sensors.begin();
}

Basic Temperature Reading

void loop() {
  sensors.requestTemperatures(); // Send command to all sensors
  float tempC = sensors.getTempCByIndex(0); // First sensor
  
  Serial.print("Temperature: ");
  Serial.print(tempC);
  Serial.println("°C");
  
  delay(1000);
}

Advanced Features

void loop() {
  sensors.requestTemperatures(); // Send command to all sensors
  float tempC = sensors.getTempCByIndex(0); // First sensor
  
  Serial.print("Temperature: ");
  Serial.print(tempC);
  Serial.println("°C");
  
  delay(1000);
}

void setHighResolution() {
  sensors.setResolution(12); // 9-12 bits (0.0625°C resolution)
  
  Serial.print("Resolution: ");
  Serial.println(sensors.getResolution());
}

float getTempF() {
  float tempC = sensors.getTempCByIndex(0);
  return DallasTemperature::toFahrenheit(tempC);
}

Troubleshooting