Dallas DS18B20

Digital Temperature Sensor

Alternative names

1-Wire DS18B20
Wired DS18B20 Sensor
DS18B20 Contact Sensor
DS18B20 Digital Thermometer

Typical applications

Monitoring the boiler temperature (boiler sensor)
Monitoring the buffer temperature (buffer sensor)
Monitoring the solar temperature (solar sensor, collector sensor)

Monitoring the aquarium temperature
Monitoring the terrarium temperature
Monitoring the animal habitat temperature
Monitoring the pool temperature (water temperature)

Monitoring the flow temperature of heating systems (flow temperature, return temperature)
Monitoring the flow temperature in ventilation systems (flow temperature, return temperature)

All this is possible with our App for Android and iOS without any programming including rules and automatic notifications on the smartphone.

Technical data

Power supply: 3V (min) – 5.5V (max)
Supported Bus Voltage Levels: 3-5.5V
Max current during conversion: 1.5mA
Max current during standby: 1µA

Temperature measuring range -55 to +125°C with ± 0.5°C accuracy (from -10°C to +85°C)
Max. sampling rate: 1.33Hz (once every 750 milliseconds)

Sensor (without sleeve):
Body size: 4.58mm x 4.58mm x 3.86mm
3 pins with 1,27mm (0.05″) spacing


If you want to connect a DS18B20 sensor to a microcontroller like the ESP8266 (ESP-12, D1 Mini, NodeMCU etc.), you have to connect the data line to the desired GPIO in addition to the supply voltage (VCC and GND). To ensure reliable operation, an additional pull-up resistor must be used between the data line and the supply line VCC. The resistor should be about 5kΩ (e.g. 4.7kΩ).

How to connect a DS18B20 Sensor with ESP8266 NodeMCU ESP-12

If there are still free GPIO’s available, we recommend to distribute several temperature sensors over them and to use a pull-up resistor each:

How to connect multiple DS18B20 Sensor with multiple single GPIO ESP8266 NodeMCU ESP-12

If there is a shortage of GPIO’s, several sensors can be connected to one GPIO (with only one pull-up resistor):

How to connect multiple DS18B20 Sensor with one single GPIO ESP8266 NodeMCU ESP-12

Of course you can also combine the different variants as you wish. The necessary configuration for this can then be easily created with our configurator.

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