arduino-to-node.md

Method 1

Arduino code for photocell sensor.

#define CDS_INPUT 0 

void setup() {
  Serial.begin(9600);
}

void loop() {

  int value = analogRead(CDS_INPUT);
  Serial.println(value);

  delay(1000);
}

The value for portName can be found from the Arduino IDE > Tools > Serial Port.

var serialport = require('serialport');
var portName = '/dev/tty.usbmodem1411';
var sp = new serialport.SerialPort(portName, {
    baudRate: 9600,
    dataBits: 8,
    parity: 'none',
    stopBits: 1,
    flowControl: false,
    parser: serialport.parsers.readline("\r\n")
});

sp.on('data', function(input) {
    console.log(input);
});

Method 2

Pass in port from the command line: node index.js /dev/cu.usbmodem1411

// index.js

var serialport = require('serialport');
SerialPort = serialport.SerialPort;
portName = process.argv[2];

var myPort = new SerialPort(portName, {
  baudRate: 9600,
  parser: serialport.parsers.readline("\n")
});

myPort.on('open', showPortOpen);
myPort.on('data', sendSerialData);
myPort.on('close', showPortClose);
myPort.on('error', showError);

function showPortOpen() {
  console.log('port open. Data rate: ' + myPort.options.baudRate);
}
 
function sendSerialData(data) {
  console.log(data);
}
 
function showPortClose() {
  console.log('port closed.');
}
 
function showError(error) {
  console.log('Serial port error: ' + error);
}

To send serial output from node.js to the Arduino, use the serialport write() function like so:

myPort.write("Hello");