Tasmota DS18B20 Temperature Sensor Node - image 1
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Tasmota DS18B20 Temperature Sensor Node

Build a WiFi temperature monitoring node using a DS18B20 1-Wire sensor and any ESP8266/ESP32 board running Tasmota. Supports up to 8 sensors per GPIO with MQTT publishing to Home Assistant.

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Boards:ESP8266ESP32ESP32-C3
Firmware:Tasmota
Use Cases:Temperature MonitoringHome AutomationEnvironmental MonitoringAquarium Monitoring
GitHubBlog Post

Tasmota DS18B20 Temperature Sensor Node

One of the simplest and most reliable Tasmota projects — connect a DS18B20 digital temperature sensor to an ESP8266 or ESP32 board and get WiFi-connected temperature readings published via MQTT.

Why This Project

  • Ultra-low cost — under $5 total (ESP-01S + DS18B20 + resistor)
  • Extremely reliable — DS18B20 is a proven industrial sensor
  • Multi-sensor support — up to 8 sensors on a single GPIO pin
  • Waterproof versions available — ideal for outdoor, aquarium, and pipe monitoring
  • No calibration needed — factory-calibrated ±0.5°C accuracy

Components Required

Component Purpose Est. Cost
ESP8266 board (Wemos D1 Mini, ESP-01S, or NodeMCU) WiFi microcontroller $2-4
DS18B20 sensor (TO-92 or waterproof probe) Temperature measurement $1-3
4.7kΩ resistor Pull-up for 1-Wire data line $0.01
Jumper wires Connections $0.50

Wiring Diagram

DS18B20          ESP8266 (D1 Mini)
─────────        ─────────────────
Pin 1 (GND)  →   GND
Pin 2 (Data) →   GPIO4 (D2)  ←── 4.7kΩ resistor to 3.3V
Pin 3 (VCC)  →   3.3V

Important: The 4.7kΩ pull-up resistor between Data and 3.3V is required for reliable readings. On ESP8266, you can optionally use SetOption74 1 to enable the internal pull-up instead.

Tasmota Setup

  1. Flash Tasmota (tasmota-sensors.bin for ESP8266 or tasmota32 for ESP32)
  2. Connect to WiFi via Tasmota AP
  3. Go to Configuration → Configure Module
  4. Set the GPIO connected to DS18B20 to DS18x20
  5. Reboot — readings appear automatically on the dashboard

Multi-Sensor Configuration

Connect multiple DS18B20 sensors to the same GPIO pin (they share the 1-Wire bus):

# Name individual sensors by their ROM address
DS18Alias 28FF1234,Kitchen
DS18Alias 28FF5678,Bathroom

# Set decimal precision
TempRes 2

# Set telemetry period (seconds)
TelePeriod 60

Home Assistant Integration

Tasmota auto-discovers DS18B20 sensors in Home Assistant via MQTT. Each sensor appears as a separate temperature entity. For manual configuration:

mqtt:
  sensor:
    - name: "Kitchen Temperature"
      state_topic: "tele/tasmota_sensor/SENSOR"
      value_template: "{{ value_json.DS18B20.Temperature }}"
      unit_of_measurement: "°C"

Compatible Boards

Any ESP8266 or ESP32 board running Tasmota works. Most popular choices:

  • Wemos D1 Mini — best for prototyping, many free GPIOs
  • ESP-01S — cheapest option, fits in tiny enclosures
  • Sonoff BasicR2 — add sensor to the internal header
  • Sonoff TH Elite — has a dedicated sensor jack (use with DS18B20 adapter)
  • Shelly Plus 1 — connect sensor to the add-on connector

Advanced: Shelly Plus Add-On

The Shelly Plus 1 and Plus 2PM support the Shelly Plus Add-On board that has a dedicated DS18B20 connector. With Tasmota, this provides a clean integrated solution for relay + temperature in one device.

Resources

Blog Post

Project writeup & details

GitHub Repository

Source code & project files