While sensors can provide local data, sometimes you want to display data from far away or data from sensors attached to other devices. This is where we can really leverage Node.js and npm packages in our favor for our Raspberry Pi projects.
Back in Chapter 2, Creating Your First Johnny-Five Project, we used the color npm module to manage colors for us. We've used the barcli module to get our sensor data into bar graphs. Now it's time to use the request npm module to retrieve data from websites for us! This allows us to simplify development over microcontrollers that use C by not having to create HTTP requests by hand each time, and being able to use asynchronous calls.
For those unfamiliar with the request module, we'll use it to make HTTP GET requests like so:
const request = require('request')
request.get(url, (err, response, body) => {
console.log(body)
})We give the request.get() call a URL and a callback that...