Repository project - Github: WiFi thermostat
ESP8266 ESP32 WiFi DS18B20 OneWire Dallas HTML Webserver WebSocket JSON mDNS UART
Teplotný senzor DS18B20 v puzdre TO-92
Dallas DS18B20 - case TO-92
Teplotný senzor DS18B20 - vodotesné vyhotovenie
Dallas DS18B20 - exterior design
SSR relé OMRON G3MB-202P
SSR relay OMRON G3MB-202P
Elektromagnetické relé SRD-05VDC-SL-C
Electromagnetic relay SRD-05VDC-SL-C

Pinout of the DS18B20 sensor in the TO-92 housing, or in a water test version

WiFi termostat - Pinout OneWire senzora DS18B20

ESP8266 (ESP8266-12E, NodeMCU, Wemos D1 Mini)


Table connection of terminals - ESP8266

ESP8266 Relay
GND GND
VIN / VUSB (Depending on the power supply) Vcc
D2 (GPIO 4) IO
ESP8266 DS18B20
GND GND
3V3 Vcc (PIO)
D1 (GPIO 5) DATA

Wiring diagram - WiFi thermostat - ESP8266 (NodeMCU, Wemos D1 Mini):

WiFi termostat - Schéma zapojenia - plynové kúrenie

Connected WiFi thermostat - development kit NodeMCU v3 Lolin v with sensor DS18B20 on OneWire bus via breadboard:

WiFi termostat - Zapojenie cez breadboard

ESP32 (WROOM-32, DevKit V1, DevKitC V4)


Table connection of terminals - ESP32

ESP32 Relay
GND GND
VIN Vcc
D22 (GPIO 22) IO
ESP32 DS18B20
GND GND
3V3 Vcc (PIO)
D23 (GPIO 23) DATA

Wiring diagram - WiFi thermostat - ESP32 (DevKit):

Elektrotechnická schéma zapojenia pre WiFi termostat - platforma ESP32

Connected WiFi thermostat - development kit ESP32 Devkit V1 with sensor DS18B20, SSR relay OMRON G3MB-202P:

WiFi termostat - Zapojenie cez breadboard - SSR relé OMRON G3MB-202P, OneWire DS18B20, ESP32

The following types of thermostats can be replaced:

  • WiFi thermostat can be integrated instead of an existing room thermostat with COM and NO contact without any change in connection.
  • After connecting the boiler to the COM and NO contacts, it can be used immediately and controlled with the set data in the web interface.
  • Replaced thermostats during WiFi thermostat test run: - reported by thermostat users
  • EMOS Thermo
  • SALUS 091FL
  • EBERLE 525
  • HONEYWELL CM27
  • TECH CS-296