keyestudio 18B20 Module

1. Introduction

This tutorial explains how to use a DS18B20 Digital Temperature Sensor with an Arduino. You will learn how to measure ambient temperature using the sensor and display the values in the Serial Monitor. The DS18B20 is a popular, inexpensive, and waterproof-capable digital temperature sensor. It communicates over a “One-Wire” bus, which means you can connect multiple DS18B20 sensors to a single data pin on your microcontroller. The sensor provides temperature readings directly in digital form, so you don’t need an analog pin or additional ADC circuitry.

2.Specifications

Parameter	Description
Operating Voltage	DC 5V
Control Method	Arduino digital pins (D2–D13 are recommended; avoid D0 and D1 as they are used for serial communication)
Dimensions	Length：31.5 mm Width：23.5 mm

3.Required Materials

• Arduino Uno （Compatible with ESP32, STM32, Raspberry Pi, and others）

• keyestudio 18B20 Module

• Jumper wires

4.Wiring Instructions（Arduino UNO R3)

18B20 Module Pin	Arduino Pin
VCC	5V
GND	GND
S	D2（or other digital pins）

5.Sample Code

Read the ambient temperature using the DS18B20 digital temperature sensor and display the values in the Serial Monitor.

libraries download

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

// Data pin where DS18B20 is connected
// You can change 2 to any other digital pin
#define ONE_WIRE_BUS 2

// Setup a oneWire instance to communicate with any OneWire devices
OneWire oneWire(ONE_WIRE_BUS);

// Pass the oneWire reference to Dallas Temperature library
DallasTemperature sensors(&oneWire);

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  Serial.println("DS18B20 Temperature Reading Example");

  // Start the DS18B20 sensor
  sensors.begin();
}

void loop() {
  // Send the command to get temperatures
  sensors.requestTemperatures();

  // Read temperature in Celsius from the first sensor on the bus (index 0)
  float temperatureC = sensors.getTempCByIndex(0);

  // Check if reading is valid
  if (temperatureC == DEVICE_DISCONNECTED_C) {
    Serial.println("Error: DS18B20 sensor not detected or reading failed!");
  } else {
    Serial.print("Current temperature: ");
    Serial.print(temperatureC);
    Serial.println(" °C");
  }

  // Wait 1 second before next reading
  delay(1000);
}

Experimental phenomena：

• After uploading the code to your Arduino and opening the Serial Monitor (set to 9600 baud rate), the Arduino will start reading temperature data from the DS18B20 sensor.

• Approximately every 1 second (depending on the delay set in the code), the Serial Monitor will print the current temperature reading from the sensor.