{
                module: 'MMM-MyCommute',
                position: 'bottom_left',
                header: 'Google Maps',
                config: {
                        apiKey: 'xyz',
                        origin: 'xyz',
                        startTime: '05:00',
                        endTime: '20:00',
                        showUpdated: false,
                        destinations:
                                [
                                {
                                destination: 'xyz',
                                label: 'Erica commute',
                                mode: 'driving'
                                }
                                ]
                        }
                },

Thanks

@sdetweil thanks for the help (again).
I’m not sure I understand… it seems to take a second browser loading the page for the main mirror to display the module.

See my response. Every time any instance on any browser (pi/laptop) gets created, it sends a request to the server-side node_helper. This happens with most of the modules.
node_helper sends it back and all the instances get fresh data and certain functions get triggered.

Here is the client side: running when you open the broser (note the this.getdata() function.

start: function() {

    Log.info('Starting module: ' + this.name);

    //start data poll
    this.getData();
    var self = this;
    setInterval(function() {
      self.getData();
    }, this.config.pollFrequency);
      
  },

and here the client side receives the data from node_helper : note the this.isHidden=false and this.show() functions at the end.

socketNotificationReceived: function(notification, payload) {
    if ( notification === 'GOOGLE_TRAFFIC_RESPONSE' + this.identifier ) {

      this.predictions = payload;

      if (this.loading) {
        this.loading = false;
        if (this.isHidden) {
          this.updateDom();
          this.show(1000, {lockString: this.identifier});
        } else {
          this.updateDom(1000);
        }
      } else {
        this.updateDom();
        this.show(1000, {lockString: this.identifier});        
      }
      this.isHidden = false;
    }

Additional question - the startTime option doesn’t seem to be working correctly for me. The module doesn’t display in the morning on the pi/mirror, even after the specified startTime. Weirdly, when I browse to the mirror from my laptop or phone (http://ip:8080) that seems to trigger the module to display on the pi.
Any ideas there?!

I think I remember with this module that it has an odd hide/show behaviour. Are you working with MMM-pages or any module scheduler being able to hide modules?
When you open your browser, a request is sent to node_helper and it sends the data back to the module (like Sam said, ALL instances). With receipt f the data the module.show() function gets triggered, so it gets shown again while it has been hidden for some reason before.

Weirdly, when I browse to the mirror from my laptop or phone (http://ip:8080) that seems to trigger the module to display on the pi.
Any ideas there?!

this means the module is not written for multiple browser instances.

when the helper sends data back, it sends data back to ALL connected clients at the same time.
the clients need to check if the message is for them , but the helper needs info on the request to do it… so the modulename.js has to change too…

I just pushed a PR to the original repo AND to the @qistoph fork.
It provides an origin option to every destination so you can show commuting back home.
Just set any point as ‘origin’ and your home address as ‘destination’

1 looked at the code, 1 api request per destination.

This is the Traffic from the last 2 days. You can see the requests are paused last night. I made changes to the poll frequency yesterday in the afternoon, no change.

The module used up nearly all of my €300 starting balance. I wonder if this will go on like this.

API calls in the last 48 hours:

API calls in the last ONE hour:

Which I do not understand: No errors. Poll Frequency of every 15 Minutes. 2 Mirrors with 4 destinations each. So 4*8=24 API calls/hour would be what I expect to see…