@sdetweil The only difference I see between that and mine is the extra

  [ .....
]

added correct? I added the square brackets and I was still given the same errors

Hello! So I am simply trying to run this module and I am just making my arduino code send the number “17” just to test. As you can see, when I run my python code, it receives this message correctly. Below is my config file

 {
            module: "MMM-ArduPort",
            position: "bottom_right",
            header: "MMM-ArduPort",
            config: {
                portname: "/dev/ttyACM0",
                displayIcons: true,
                showDescription: true,
                hideLoading: true,
                hideWaiting: true,
                useColors: true,
                sensors: 
                    {
                        name: "Timer",
                        description: "LPG, Propane, Hydrogen",
                        maxValue: 19,
                        maxFormat: "({0} cm) TOO FAR",
                        highestValue: 30,
                        highestFormat: "({0} cm) FAR",
                        highValue: 15,
                        highFormat: "({0} cm) NORMAL",
                        lowValue: 10,
                        lowFormat: "({0} cm) CLOSE",
                        lowestValue: 5,
                        lowestFormat: "({0} cm) TOO CLOSE",
                        minValue: 0,
                        minFormat: "({0} cm) OK"
                    }
            }
        },

As you can see when I start

npm start dev

I get a plethora of errors in which I have no idea how to fix. Any help would be super appreciated.

Also here is my arduino code (almost exactly like the one supplied by MMM-arduport git page:

volatile int32_t m_counter = 0;
bool WasStarted = false;

static const char *pcMQ2Prefix = "[sensor:Timer:";
static const char *pcPostfix = "]";

void setup() {
  Serial.begin(9600);
  while(!Serial);
  
  Serial.println("[status:setup:starting]");
  
  int test = 1;
  m_counter = test;

  if(test > 1) {
    WasStarted = false;
    Serial.println("[status:setup:failed]");
    return;
  }
  
  delay(3000);
  WasStarted = true;
  Serial.println("[status:setup:started]");
  delay(100);
}

void loop() {
  //Serial.print(pcMQ2Prefix);
  //Serial.print(m_counter);
  //Serial.println(pcPostfix);
Serial.println("[sensor:Timer:19]");
  if(m_counter % 3 == 0) {
    delay(1000);
    delay(2000);
  }

  if(m_counter >= 60) m_counter = 0;
  m_counter++;

  delay(1000);
}

Thank you for the reply!
However, I sadly am still shown a black screen of doom… not too sure.

I have checked for configuration errors and this is all fine. Everything seems to go smoothly until I add my node_helper.js. I will upload my config file, main module file, and my helper. Any help would be appreciated. Can’t seem to find the reason for breaking my Magic mirror. =
MMM-Timer.js

Module.register("MMM-Timer", {
// Default module config.
   defaults: {
   	text: "Hello World!"
   },

   // Override dom generator.
   getDom: function() {
   	var wrapper = document.createElement("div");
   	wrapper.innerHTML = this.config.text;
   	return wrapper;
   },
   start: function() {
   	this.mySpecialProperty = "So much wow!";
   	Log.log(this.name + ' is started!');
   	var self = this;
   	setInterval(function() {
   	self.updateDom(); // no speed defined, so it updates instantly.
   		}, 1000); //perform every 1000 milliseconds.
   },
   notificationReceived: function(notification, payload, sender) {
   	if (sender) {
   		Log.log(this.name + " received a module notification: " + notification + " from sender: " + sender.name);
   	} else {
   		Log.log(this.name + " received a system notification: " + notification);
   	}
   },
   socketNotificationReceived: function(notification, payload) {
   	Log.log(this.name + " received a socket notification: " + notification + " - Payload: " + payload);
   }
});

node_helper.js

var NodeHelper = require("node_helper");
const { spawn } = require('child_process');
const child = spawn('~/serial_communication.py');

module.exports = NodeHelper.create({
	start: function() {
		this.mySpecialProperty = "So much wow!";
		Log.log(this.name + ' is started!');
	},
	stop: function() {
		console.log("Shutting down MyModule");
		console.log('kill');
    		child.kill();
		this.connection.close();
	},
	// Override socketNotificationReceived method.

	socketNotificationReceived: function(notification, payload) {
		Log.log(this.name + " received a socket notification: " + notification + " - Payload: " + payload);
	},

	// Test another function
	aFunction: function() {
		child.stdout.on('data', (data) => {
  			console.log(`child stdout:\n${data}`);
		});
		
		child.stderr.on('data', (data) => {
  			console.error(`stderr: ${data}`);
		});
		child.on('close', (code) => {
  			console.log(`child process exited with code ${code}`);
		});
		//want to return the python subprocess
		this.sendSocketNotification('MY_TIMER_DATA', data);
	}
});