Running trains wirelessly

Something I have been meaning to try out for a while is the “WiThrottle” mode of the JMRI DecoderPro software, which is supposed to allow you to control trains with an iOS or Android mobile device (phone or tablet).

Well, I don’t have an iOS device, and right now I don’t have a tablet (I left it on an aeroplane in Manila, long story), but I do have an Android phone – a Google/LG Nexus 5X.

So I checked out the WiFi Throttle page of the JMRI documentation, and learned that I could choose between 2 Android apps – Engine Driver and Digitrains.

I installed Engine Driver from the Google Play Store, and then opened the WiThrottle page of JMRI settings, where it said it would listen for throttles on port 12090.

On opening Engine Driver on my phone, it asked for an address and a port. I went to my Mac’s Network Utility and saw that its address (on my home network) was So I entered the address and port into Engine Driver. No go. A “can’t connect” message was shown.

I tried disabling my Mac’s firewall but no change. Then I saw a checkbox on the JMRI WiThrottle settings page which said “start automatically when JMRI starts”. So I ticked it and restarted JMRI, which now opened an extra small window saying it was ‘advertising’ for throttles over wifi.

Now we were cooking. Engine Driver connected straight away, and asked me to choose a loco to control. I don’t like leaving my firewall off, so now I switched the Firewall back on, and added DecoderPro to the list of programs that could listen through it. Still OK.

So I chose a loco, dragged the speed slider and presto – a moving train.

And it was really as simple as that. By touching the add engine button on the app, I could add a second loco and it split the screen into two halves, letting me control both individually. If I had a tablet I think it would probably let me control three or four locos at once, but I think the phone’s screen would be pushed to show more than two sets of controls.

One nice thing was that the Engine Driver throttle controls were definitely more responsive than using the on-screen throttles in JMRI. JMRI’s throttle windows often had a delay between clicking a slider or button and the loco actually responding (or turning on its lights, or whatever). Not so with the app – the response was almost instantaneous.

So I can now walk around my (still not built) layout and control my trains on the hoof. I am one happy camper.

Today’s temporary testing layout…

After all this fun, I decided to try out the Digitrains app to see if it was actually better than Engine Driver, but after wrestling with its settings for 10 minutes and failing to move any locos, I uninstalled it. Engine Driver is fine. Its interface is a bit clunky but it works perfectly.

All I have to do now is work out why, when I add a third loco to the track, it keeps starting and stopping (and so do the other locos on the track) when trying to make it move with a throttle. It feels like an insufficient power issue, even though I was told that the Sprog should be able to control several locos at once. But I’ll save that problem for another day.

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