Raspberry Pie

October 14, 2015

pi1l

Yum! Who doesn’t love a slice of pie? The Raspberry Pi is a cheap, credit-card sized computer that plugs into a computer monitor or TV, and uses a standard keyboard and mouse. It runs Linux and is capable of doing everything you’d expect a desktop computer to do, from browsing the internet and playing high-definition video, to making spreadsheets, word-processing, and playing games.

And it runs JMRI Model Railroad Interface!! Or it is supposed to…

IMG_0771

I have been playing around with it and it works… sort of. With no Linux programming experience and some help from my company’s IT guru (who sold me his used Raspberry Pi model B for $20) I have DecoderPro up and running on the Pi and can turn main track power ON and OFF by using DecoderPro and also can control a loco on the mainline with a JMRI throttle.

But, for some reason, I am getting a serial port error (see pic above) in the JMRI preferences pane and can NOT read or write or program any brand of DCC decoder. Which is strange as you’d think that JMRI would either communicate and work or NOT communicate and not work at all.

Since it is a serial port issue I googled “Raspberry Pi JMRI Serial Port issue” and found this post online at http://www.nscale.net/forums/showthread.php?37250-JMRI-on-a-Raspberry-Pi-2

One issue that Raspberry Pi users run into is that JMRI requires a package called RXTXcomm. It is included with JMRI but the version included does not work on the Raspberry Pi. That means you must install the package from scratch and then replace the file included with JMRI with the one in the newly installed package. (A file named RXTXcomm.jar should be copied to the /opt/JMRI/lib folder.) Once I had JMRI and the supporting packages installed I plugged in my Digitrax PR3 to the remaining USB port (remember I used one for Wifi, one for the keyboard and one for the mouse). I then started JMRI and it opened at the “Preferences” window where I selected “Digitrax” for the interface manufacturer and PR3 as the interface. From the drop-down menu I was able to select the USB port the PR3 was plugged into. Finally I selected the Command Station I have (Zephyr). If you don’t have your interface connected to the RPi2 and powered up when you start JMRI you will get an error indicating the hardware wasn’t found. Also you need an external power supply for the interface because the RPi2 USB ports can only supply about 100mA of current.

Like all things computer, more googling is necessary and I need to find the time to ask for help at https://groups.yahoo.com/neo/groups/jmriusers 

When I get it fully up and running I will (re)post this entry with the process and (hopefully) the solution.

4 Comments

  1. Matt

    What are the plans with this? I have a model B that needs a project idea 🙂

    Reply
    • bernardhellen

      Sorry for the delay in getting back to you. Funnily the post posted before I finished it – which I will do later this week. The Pi was originally bought to be used for sound and light automation to get the TARDIS up and running however…..

      The plan is now to get JMRI running and have a full time dedicated JMRI server. I’ll let you know if and hopefully when I get it running.

      Reply
      • Matt

        I definitely look forward to how things turn out for you, I recently tried getting my PI setup as a JMRI server but had issues getting it working and gave it up for a while in frustration

        Reply
        • bernardhellen

          It’s up and running (sort of) and I will post details later this weekend! Still tweaking a serial port issue but I can load and run DecoderPro on a Pi!!!

          Reply

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