Having your windows connected to home assistant opens many possibilities. I've written down some ideas on what you could do with such information:
- 🚨 Create an alarm panel, so when a window is being opened while you are away, the siren rings and you get a text message
- 📱 Be notified which windows are still open before you leave
- 🌡️ Turn off the heater when someone opens a window
- ❄️ Ring a bell when the windows are open for too long
- ... and possibly much more
How to do this
We will add magnet contacts to every window and wire them all to an ESP8266. There are other possibilities like using wireless contacts, but if you are on a budget or already have sensors pre-wired in your home this is a cheap and reliable way.
Let's begin with wiring everything together. The magnet contacts close the circuit when the magnet is near them, and is open when not. We will connect one wire of the contact to a digital pin. Not all pins are usable as inputs on the NodeMCU board, so make sure to connect to one of these pins: D0, D1, D2, D5, D6 or D7. You don't have to use four window contacts as I do but if you want to connect more than six you probably need to use a shift register to get more ports (or use another node).
Writing the program
Using esphomeyaml, flashing the nodemcu becomes a no-brainer. If you already know yaml files from home assistant, it should be easy for you to follow.
To install ESPHome, visit the official documentation.
Keep in mind to alter the pins to your chosen ones. If you want to add contacts, just copy one of them and make sure all the indents are correct.
esphomeyaml: name: window_contacts platform: ESP8266 board: nodemcuv2 wifi: ssid: !secret wifi_ssid password: !secret wifi_password # Enable logging logger: ota: api: binary_sensor: - platform: gpio pin: number: D1 mode: INPUT_PULLUP name: "Small Window" device_class: window - platform: gpio pin: number: D2 mode: INPUT_PULLUP name: "Balcony Door" device_class: window - platform: gpio pin: number: D6 mode: INPUT_PULLUP name: "Wide Window" device_class: window - platform: gpio pin: number: D7 mode: INPUT_PULLUP name: "Side Window" device_class: window
Connect everything and run
esphomeyaml window_contacts.yaml run.
To add the entities to your home assistant instance, visit https://www.home-assistant.io/components/esphome/.
We connected simple reed switches (window contacts) to a nodemcu (esp8266). We then wrote a simple program using esphomeyaml to report the states to home assistant. After uploading this sketch, everything should be up and running fine.
Update 2019/01/17: updated for new ESPHome native API