What to buy for the Wifi Smart Thermostat?

In this section, you will learn about all the hardware devices that you will need to buy your own Wifi Smart Thermostat.

The basic components to build your Smart Thermostat are:

  • An old Android 4.4+ device, that will act as the main controller. You can use an old smartphone or tablet. This device has to stay at your home and will be always on because it will control your boiler and communicate with the cloud and the client app.
  • At least one ESP32 mcu.
  • With a DHT11 or DHT22 temperature/humidity sensor and a
  • A one channel relay.
  • Some protoboard cables.

The above are the components needed for the minimum viable setup. You may add as many nodes as you want (for example, to register the temperatures in other rooms of your house). But you have to take into account that you can only have one relay per thermostat.

If you have doubts, don’t hesitate and ask in our forum, before buying anything.

And we assume that you have an Android device (smartphone or tablet) to install the client app and control the Smart Thermostat, and an internet (wifi) connection at home 🙂

1.- A one channel relay

You can use a low level triggered relay, or a high level triggered relay. For example:


2.- Protoboarding cables

You will need male-male cables, male-female and female-female, like these:


3.- ESP32 board for a wireless sensor or wireless relay

You need at least one ESP32 board, in combination with a relay and a temperature sensor. Or you can split this unit in two, and have two separate ESP32, one with a relay, and one with a temperature sensor. Of course, you can add as many temperature nodes as you want.


4.- DHT11 and / or DHT22 Temperature Humidity sensor

For the wireless sensor, you will need one of these (connected with the ESP32). The DHT11 is the cheapest sensor, but the DHT22 is better, more precise and reliable. We strongly recommend the DHT22 sensor.

DHT 11: https://amzn.eu/d/b4jFDEO

DHT 22: https://amzn.eu/d/0rTgBfK

5.- Micro USB cables

To power the Pi and the ESP32 boards, you will need micro USB cables.

6.- 5V chargers

And to deploy your wireless sensor and the Pi across your home, you will need 5V chargers to power them. Something like that (or you can reuse old smartphone chargers):