Hardware Guide of Pool Controller

This Hardware Guide will describe how to setup the hardware of the controller.

Parts List (BOM)

  • 1 * ESP8266 NodeMCU Controller ( Amazon)
  • 2 * DS18B20 Temperature Sensors ( Amazon)
  • 1 * Relais-Module 5V ( Amazon)
  • 1 * Breadboard and wires to connect (alternativly soldering of the circuit)


The circuit of the controller could be found on following image based on a breadboard wireing:

Breadboard Circuit of Pool Controller

The source Fritzing file could be found in GitHub project: pool-controller.fzz

ESP8266 PIN Usage

The ESP8266 is connected using following PINs. You can find the constant values within the sources of main.cpp (first column of table) which are associated to the pins.

Constant in Source PIN of ESP8266 Description
PIN_DS_SOLAR D5 Pin of temperature sensor (DS18B20) for solar storage
PIN_DS_POOL D6 Pin of temperature sensor (DS18B20) for pool water
PIN_RELAY_POOL D1 Pin to connect relais for pool pump
PIN_RELAY_SOLAR D2 Pin to connect relais for solar pump

Power Supply

In my environment I use the USB to power the ESP8266 via small USB-Power-Adapter andan additional 230V power plug to be used as source for the power of the pumps which are switched via the relais.