A weekend gardening project I designed for a small greenhouse in Reykjalundur, Iceland, grown and maintained by a farmgeek friend of mine, Nick Robinson. Growing squash in Iceland seems to be tough so he wanted constant temperature measurement in soil and air.
The sensors used are ds18b20. The application backend is scalable and will read values from all sensors it can find and save it to DB.
See DEMO
note: the demo is generating random numbers since the Pi and the sensors are occupied :-)
First of all, you need the Pi, the sensors and other stuff to hook them up.
I bought and followed everything in this tutorial.
After you have wired everything up correctly and the sensors are working you can install the app.
$ git clone https://github.com/busla/farmpi
$ npm install
$ bower install
$ npm start
There are configuration files in the config folder that can be modified. To load the appropriate config file, add NODE_ENV variable with the name of your environment:
$ export NODE_ENV=raspberrypi
Node will load the settings from the file with the corresponding filename.
"Sensors": {
"device": "raspberrypi",
"saveInterval": 15, // minutes
"currentTempInterval": 1, // seconds
}
I used NeDB database since it´s a node module and has an API similar to MongoDB. The app iterates over connected sensors and stores their id, value and type (user defined) with a timestamp. Drawing this data on a line graph with time on X axis and temperature on Y becomes relatively simple.
Socket.IO is used to pipe new temperatures to the clients and draw on the chart. The data is live on the screen.
You can pass {'from': $date, 'to': $date}
to /api/chart and get the following json:
{
"sensors": [{
"id": "28-000006a3684e",
"type": "soil",
"currentTemp": 22.755530063528568
}, {
"id": "28-000006a36dbe",
"type": "air",
"currentTemp": 22.94879347225651
}],
"date": 1435613824213,
"_id": "qwBoea1IznS2xbN7"
}
To run the app independently on your Pi, install the forever
module. It will run on port :3000, but if you want to run it on port 80, you can route all requests from 3000 > 80 with the following command:
$ sudo npm install -g forever
$ cd your-project
$ sudo forever start your-app-name.js
sudo iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3000
Also, to start on boot you can install forever as a service with the, you guessed it, forever-service module.
$ sudo npm install -g forever-service
You will have to add the $PATH variable to you startup script, for example:
$ cd farmpi
$ sudo forever-service install farmpi -e "PATH=/usr/local/bin:\$PATH"
You can read temperatures within a selected date range.
- Fork it!
- Create your feature branch:
git checkout -b my-new-feature
- Commit your changes:
git commit -am 'Add some feature'
- Push to the branch:
git push origin my-new-feature
- Submit a pull request :D
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