The DS18B20 is a digital temperature sensor manufactured by DS18B20. It communicates over a 1-Wire bus, requiring only one data line (and ground) for communication. This sensor provides temperature readings in Celsius with a resolution ranging from 9 to 12 bits, making it highly versatile for applications requiring precise temperature monitoring. Its compact design and ease of integration make it a popular choice for hobbyists and professionals alike.
This circuit is designed to measure temperature using a DS18B20 sensor interfaced with an Arduino UNO. The Arduino reads temperature data from the sensor via a 1-Wire bus with a pull-up resistor and outputs the readings to the serial console.
Open Project in Cirkit Designer
This circuit involves an Arduino UNO microcontroller interfacing with a DS18B20 temperature sensor. The sensor is powered by the Arduino's 5V and GND pins, and its data pin is connected to a digital I/O pin on the Arduino, with a pull-up resistor in place. The setup is designed to read temperature data from the sensor.
Open Project in Cirkit Designer
This circuit features an ESP8266 NodeMCU microcontroller connected to a DS18B20 temperature sensor. The sensor's data line (DQ) is connected to the D2 pin of the NodeMCU through a 4.7k ohm pull-up resistor, which is a common configuration for one-wire temperature sensors. The sensor is powered by the 3.3V supply from the NodeMCU, and both the sensor and the NodeMCU share a common ground.
Open Project in Cirkit Designer
This circuit is designed to monitor temperatures using multiple DS18B20 1-Wire temperature sensors connected to an Arduino UNO microcontroller. The sensors are powered by the Arduino's 5V output and share a common data line (DQ) connected to digital pin 2 through a 4.7kΩ pull-up resistor, allowing for simultaneous temperature readings. The Arduino runs a sketch that reads temperatures from each sensor and outputs the readings to the serial monitor in both Celsius and Fahrenheit.
Open Project in Cirkit DesignerThe DS18B20 is designed to operate efficiently in a wide range of environments. Below are its key technical details:
| Parameter | Value |
|---|---|
| Operating Voltage | 3.0V to 5.5V |
| Temperature Range | -55°C to +125°C |
| Accuracy | ±0.5°C (from -10°C to +85°C) |
| Resolution | Programmable (9 to 12 bits) |
| Communication Protocol | 1-Wire |
| Max Current Consumption | 1.5mA during conversion |
| Standby Current | 750nA (typical) |
| Conversion Time | 93.75ms (12-bit resolution) |
| Package Types | TO-92, SOIC-8, or waterproof probe |
The DS18B20 typically comes in a 3-pin TO-92 package. Below is the pinout:
| Pin | Name | Description |
|---|---|---|
| 1 | GND | Ground connection |
| 2 | DQ | Data line for 1-Wire communication |
| 3 | VDD | Power supply (optional, can operate in parasite mode) |
Note: In parasite power mode, the sensor can operate without a dedicated VDD pin by drawing power from the data line.
The DS18B20 is straightforward to use in a circuit, thanks to its 1-Wire communication protocol. Below are the steps and considerations for using the sensor:
Basic Wiring:
Parasite Power Mode:
Below is an example of how to use the DS18B20 with an Arduino UNO. This code reads the temperature and displays it on the Serial Monitor.
#include <OneWire.h>
#include <DallasTemperature.h>
// Pin where the DS18B20 data line is connected
#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 DallasTemperature library
DallasTemperature sensors(&oneWire);
void setup() {
Serial.begin(9600); // Initialize serial communication at 9600 baud
sensors.begin(); // Start the DS18B20 sensor
}
void loop() {
sensors.requestTemperatures(); // Request temperature from the sensor
float temperatureC = sensors.getTempCByIndex(0); // Get temperature in Celsius
// Check if the reading is valid
if (temperatureC != DEVICE_DISCONNECTED_C) {
Serial.print("Temperature: ");
Serial.print(temperatureC);
Serial.println(" °C");
} else {
Serial.println("Error: Sensor not detected!");
}
delay(1000); // Wait 1 second before the next reading
}
Sensor Not Detected:
Incorrect Temperature Readings:
Multiple Sensors on the Same Bus:
getAddress() function in the DallasTemperature library to identify each sensor's unique address.Q: Can I use multiple DS18B20 sensors on the same data line?
A: Yes, the DS18B20 supports multiple devices on the same 1-Wire bus. Each sensor has a unique 64-bit address for identification.
Q: What is parasite power mode?
A: In parasite power mode, the sensor draws power directly from the data line, eliminating the need for a dedicated VDD connection.
Q: How do I increase the accuracy of temperature readings?
A: Use the highest resolution (12-bit) setting and ensure the sensor is properly calibrated and powered.
Q: Can the DS18B20 measure negative temperatures?
A: Yes, the DS18B20 can measure temperatures as low as -55°C.
By following this documentation, you can effectively integrate the DS18B20 into your projects for reliable and accurate temperature sensing.