node.js serialport arduino test

runSerial.js

/* Dialog library*/
const dialog = require('dialog');

/* Serial communication library*/
const SerialPort = require('serialport');
const Ready = require('@serialport/parser-ready')
const ReadLine = require('@serialport/parser-readline')

var arduino_com_port = 'comX';

/* List all serial ports and try to connect, if Arduino, save COM path. */
function findCom(){
	/* For each com ports, open a test connection. */
	SerialPort.list(function (err, com_ports) {
		com_ports.forEach( function(port) {
			var testSerial = new SerialPort(port.comName, { baudRate: 115200});
			var readyparser = testSerial.pipe(new Ready({ delimiter: 'ArduinoItsMe' }));
			
			testSerial.on('open', function () {
				console.log('try serial port', port.comName);
			});
			
			/* If we have a "ArduinoItsMe" message as reply we find the right com port, save it and continue. */
			readyparser.on('ready', function() {
				console.log('Arduino found at ', testSerial.path);
				arduino_com_port = testSerial.path;
				return;
			});
			
			/* After a while, close the com port */
			setTimeout(function(){ 
				testSerial.close(function () {
					console.log(port.comName, ' closed.');
				});	 
			}, 2000);
			
		});
	});
}

function begin(){
  
	/* Send data to Arduino from command line if necessary */
	const readline = require('readline').createInterface({
		input: process.stdin,
		output: process.stdout
	});
	
	readline.on('line', (input) => {
		console.log('Received: ', input);
		sendToSerial(input);
	});
	
	
	/* Start working communication with Arduino */
	var myPort = new SerialPort(arduino_com_port, { autoOpen: false, baudRate: 115200 });

	myPort.open(function () {		
		console.log('Start communication with Arduino on ' + arduino_com_port + '.\nData rate: ' + myPort.baudRate);
		const lineStream = myPort.pipe(new ReadLine());
		
		myPort.on('close', showPortClose);						// called when the serial port closes
		myPort.on('error', showError);							// called when there's an error with the serial port
		lineStream.on('data', readSerialData);					// called when there's new data incoming
	});	 
	

	/* Serial event functions: */
	function showPortClose() {
		console.log('Serial port closed.');
	}
	function showError(error) {
		console.log('Serial port error: ' + error);
	}

	/* This is called from parser when new data comes into the serial port */
	function readSerialData(data) {
		console.log(data);
		var arduinoMsg = data.toLowerCase();
		if(arduinoMsg.indexOf('error') > -1){
			dialog.warn(data, 'Warning', null);
		}
	}

	/* This is called from for send data to serial port */
	function sendToSerial(data) {
		//console.log("Sending to serial: " + data);
		myPort.write(data);
	}

}


/* The script start here */
console.log('\n\nSearching Arduino board...');

// Search the Arduino com port
findCom();

// Wait just a little before start communication with board
setTimeout(function(){ 
	// Start Arduino connection
	if(arduino_com_port != 'comX')
		begin();
	else
		dialog.err('Arduino board not found', 'Error', null);
}, 3000);

test.ino

#define TEST_BUTTON 2
String rxText; 
 
void setup() {
  pinMode(TEST_BUTTON, INPUT_PULLUP);
  
  Serial.begin(115200); 
  delay(500);
  /* Send string "ArduinoItsMe" in order to find the right COM port */
  for(byte i=0; i<3; i++){
    Serial.println("ArduinoItsMe");
    delay(200);  
  }
 
}
 
void loop() {  
  if(digitalRead(TEST_BUTTON) == LOW){    
    String txText;
    txText = "Something wrong. Error at time" + String(millis()) + " ms.";    
    Serial.println(txText);
    delay(200);    
  }

 
  while(Serial.available()){
    char inChar = Serial.read();
    rxText += inChar;
    if(inChar == '\n'){
      Serial.print("Received: ");
      Serial.println(rxText);
      rxText = "";
    }
  }
 
  
}