stavrosdidakis / NodeMaxMQTT

Code examples that demonstrate a communication system between Node.js and Max using Socket.IO. An example also demonstrates how to extend this relationship by adding MQTT functionality

Max + Node.js + Socket.IO + MQTT

1_NodeToMax-MaxToNode

In this example, we develop a communication system between Node.js and Max using sockets.

To run this project, start the NodeJS server:

cd <NodeJS-folder>
npm install
npm start

The code will execute a server on the localhost and port 5001. There are two variables with randomly generated numbers every 3 seconds. These are sent to Max, where they are extracted using the same topic name (i.e. msg1FromNode).

In Max, we open the file socketio-client.maxpat. From here, we need to execute

• script npm install
• script npm start
• and click to “connect http://localhost:5001”.

If successful, we will be able to see the random numbers coming out of the route objects. Finally, we can send a message from Max to Node by controlling the number connected to the messageFromMax $1.

2_NodeMaxMQTT

This example extends the previous one by adding MQTT functionality to the Node.js server.

Follow the same install instructions as in the previous example. To use your own MQTT server, you need to add your MQTT broker URL (in this case HiveMQ is used), together with your username and password. If set correctly, you will be able to receive in Max messages from an MQTT broker (on a chosen topic), and also to send data from Max to an MQTT broker as well.

//MQTT settings
  const clientMQTTID = Math.random().toString(16).slice(3);
  const options = {
    username: '{replace here}',
    password: '{replace here}',
    clientMQTT: clientMQTTID
  };

  //Connect to a HiveMQ Cluster. Insert your own host name and port
  const clientMQTT = mqtt.connect('tls://{replace here}.s1.eu.hivemq.cloud:8883', options);
  //Topics for MQTT
  const inTopic = "/inTopic/";
  const outTopic = "/outTopic/";