In this section you will learn about all the hardware devices that you will need to buy your own Smart Thermostat.
Before buying the components, please decide how your infrastructure will look like, because not all components are mandatory. For example, you have to decide if you will use wireless sensors (then you will need ESP32 boards and DHT11 sensors), or you will use connected sensors (then you will need a BME280 Temperature Humidity sensor and some cables).
If you will have wireless temperature sensors you have to decide how many, but take in account that you can have only one connected temperature sensor.
The same is valid for the relay. You have to decide if you will connect physically to the Pi, or if you will control the relay wirelessly with an ESP32 board. At this stage of the development the thermostat only can control one (1) relay.
If you have doubts, don’t hesitate and ask in our forum, before buying anything.
Depending on what infrastructure you decide, some components are optional, but have in mind that you will need at least:
- One Raspberry Pi3B or an old Android 4.+ Smartphone or Tablet play the role as Thermostat.
- One temperature / humidity sensor:
- A BME280 if physically connected to the Pi, or
- An ESP32 board and a DHT11 to have a wireless sensor.
- A High level Triggered Relay:
- Only the relay if you want to connect it physically to the Pi, or
- The relay and an ESP32 board if you want to control the relay wirelessly.
- Some protoboarding cables if you are using wired connections.
And we assume that you have and Android device (smartphone or tablet) to install the client app and control the Smart Thermostat, and a internet (wifi) connection at home 🙂
1.- Raspberry Pi 3B (Smart Pi Thermostat only).
2.- BME280 temperature humidity sensor (Smart Pi Thermostat only).
Please be aware that you have to soldier yourself the pins for this sensor, and for that you need a soldering iron.
3.- Touch screen for the Pi (Smart Pi Thermostat only, and optional).
A touch screen for the Pi3 is optional. You can use an external monitor to install the image on the Pi and configure the thermostat. After that you can use the Android app to control it. But having a touch screen for the Pi makes all a little bit easier (and cooler).
This model works reasonably well with the Android Things os and the Pi3, but the screen resolution is not “state of the art”. Maybe other touch screens work well too.
4.- A High Level Triggered Relay
The high level triggered relays are not easy to find. Normally all the relais for proto boarding are low level triggered. But make sure you buy a high level one, because we want that if the Smart Thermostat is powered off, the relay will remain open and the heating stops.
5.- Protoboarding cables
You will need male – male cables, male – female and female – female, like these:
6.- ESP32 board for a wireless sensor
If you are planning to read the sensor or control the relay wirelessly, then you need one Esp32 for each wireless node that you are planning:
7.- 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.
8.- Micro Usb cables
To power the Pi and the ESP32 boards, you will need micro usb cables. You can use cables that you have already, but if you not:
9.- 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 smarphone chargers):
10.- 16Gb or greater MicroSD card for the Pi.
The Raspberry Pi need a MicroSd card. 16Gb are more than enough.