node_helper and python communication

  • Hi,

    I have started to dig in developing own modules. I wanted to use an ultrasonic sensor to check if a person is in front of the mirror minimum 100cm. In this case the python script sends a ‘message’ with a type event and distance in cm. This should turn off the screen. Then a timer (5sec) starts to switch off the screen again as long as there is no message coming in.

    I have several problems and don’t know why:

    1. the timer never starts
    2. my console logs are only displayed AFTER the magic mirror app is stopped.

    Can anyone give me a hint? Or is there a better implementation for the communication between python and the modules?

    module.exports = NodeHelper.create({
        python_start: function() {
        		pyshell = new PythonShell('');
        		pyshell.on('message', function (message) {
        switchScreenOff: function(){
        	console.log("Switch screen off");
        switchScreenOn: function(){
        	var self = this;
          console.log("Switch screens on");
        	timer = setInterval(self.switchScreenOff, 5000);

  • @jmagsumbol Should the function be simply called start()? Does python_start() ever get called?

    Alternatively, with a slight modification of MMM-PIR-Sensor, I think this could all be done within Node.js. You’d just need to examine how to handle the GPIO of the ultrasonic sensor in however it differs from a PIR sensor.

    For actually turning the screen off and on, check out @cruunnerr‘s guide:

  • @ninjabreadman yap python_start is called by an event from the modules (script is not complete)
    In the MMM-PIR-Sensor the GPIO is used. In my case I would like to use usb. So i should require node-serial port. That’s what one way I can try it.
    But I also thought of doing the complete logic, like switching on/off the screen, in my python script. So the only job of the module is to call python.

Log in to reply

Looks like your connection to MagicMirror Forum was lost, please wait while we try to reconnect.