Guide to getting Arduino data to the browser with Express
This repository acts as an extremely short guide to connecting an Arduino to the internet using Node.js and Express, showing data from an Arduino on the most basic web site.
Install serialport and express dependencies
npm install serialport express
Install the Arduino code
The example code in arduino/ reads analog input A0 every second and sends the value as a string over the serial port. Upload it to your Arduino. It doesn't matter if nothing's connected, we'll get some free noise if nothing is connected.
First server: Track the Arduino from node
The server1.js example reads the Arduino's serial port and prints out the data. Run
node server1.js
You may have to configure the port (e.g., to "COM3" on a windows), or dependent on your setup (e.g. a different USB device on a mac or linux), in server1.sh:
var portName = '/dev/tty.usbmodem1421';
Second server: Hello World with Express
The server2.js example is the Hello World for Express. Run
node server2.js
and open http://localhost:3000/ in your browser. Hi, there.
Third server: Get the Arduino's data into your web browser
The final server3.js combines these two functionalities.
It tracks input from the Arduino and stores it in a data variable. Upon a HTTP request, it returns this stored data.
Besides adding this data variable, the previous two examples have simply been merged.
Make sure to configure the portName in this script as with the first server. Run
node server3.js
and open http://localhost:3000/ in your browser to see the last retreived data from the Arduino.