automate your greenhouse with a Raspberry Pi zero some sensors and firebase.

You can read more about how this project was made on kalleott.de/iot

Install dependencies

npm install
cd functions
npm install
cd ..

The UI code for this application is react based and enables you to see the current greenhouse state (temperature, air humidity and soil moisture values). With a slider you can edit the current reference value to determine "dry" moisture values. It is dry when the sensor value is bigger than the reference value.

The code running on the Raspberry Pi is located in the device/index.js file. It can be started with 2 arguments, the interval in milliseconds (-interval 60000 or --verbose 60000) in which the sensors should trigger and a verbose (-v or --verbose) flag for more logging. The default interval is 1800000 which is equivalent to 30 minutes.

node index.js -v -i 5000

The wiring diagram can be seen in the greenhouse-schematics.png image.

For the connection to firebase generate a new private key in "service accounts" of the project settings in the firebase console and save it as firebase-key.json in the same folder as the device app on the Raspberry Pi.

To add functions to your project you can init a project in the functions directory with the command firebase init. This project has a main index.js file and every exported function (exports.functionName) is deployed as a firebase function.

For example the function to check if the plants are dry on a new soil sensor value looks like this:

exports.checkIfPlantsAreDryOnSensorChange = functions.firestore
  .document('/soilMoistureData/{eventId}')
  .onCreate(async snap => {
    const sensorValue = snap.data().value

    const reference = await getDryReferenceValue()

    updateIsDry(sensorValue, reference)
  })

To learn more take a look in the functions/index.js file.

• install firebase-tools:
  • npm install -g firebase-tools
• login with the firebase tools
  • firebase login
• connect to an existing firebase project
  • firebase use
• change firebase API keys and URLs to use your own project

This application uses an gmail account to send emails to listed users in the users collection when the soil gets dry. So you need to use an existing account or create a new one. To enable the cloud functions to send emails you must set 2 environment variables for firebase:

firebase functions:config:set [email protected]
firebase functions:config:set gmail.password=thePasswordForThisAccount

To deploy the application start with building the UI app, then run the firebase deploy command:

npm run build
firebase deploy