Can DCC++EX Run Auto-Reverse Loop Instead of Programming Track

BigJake Aug 5, 2021

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  1. BigJake

    BigJake TrainBoard Member

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    Background: The upcoming Pi SPROG 3 Plus has two DCC outputs, the 2nd of which can be for either a Programming Track or an Auto-Reverse Loop (selectable via JMRI profile setting)

    Is it possible & practical to do the same with DCC++EX, using the existing Programming Track output for the AR/Programming track?

    Could this option be selected via JMRI profile setting or similar?

    How many users would be interested in this capability?

    Thanks in advance...
     
    Mark Ricci likes this.
  2. Woodhead

    Woodhead New Member

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    Newbie here so please be gentle especially as this is opening and oldish thread. I would use track sensors, an Arduino Uno and relay to do this automatically. You could even incorporate a servo to switch the point for the return. There are plenty of videos on YouTube on this approach. It would also mean that you get to keep your programming track.
     
    BigJake likes this.
  3. BigJake

    BigJake TrainBoard Member

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    Woodhead, Welcome aboard!

    What you propose is certainly doable, with additional equipment and software, on a base DCC++EX hardware setup. However, no additional equipment would be necessary to repurpose the existing secondary track output from programming to reverse loop booster duty. Only software needs to be updated, IINM.

    I am a big proponent of "keep it simple". If mere current (e.g. "short circuit") detection for the reverse loop can provide the auto-reversing function, why make it more complicated with multiple occupancy detectors and software logic, etc. (unless you already need all that for controlling signals, etc.)

    Since I wrote the original post to this thread, the Pi SPROG 3 Plus is now an official SPROG product, available for purchase from SPROG or their US distributor. Under JMRI control, the secondary track bus output can be used for a programming track, a secondary booster, or an auto-reversing booster. The same current sensing capability that is used for the programming track (response detection) and short circuit protection is used to detect the entrance to and/or exit from the reversing loop. There's nothing to prevent the secondary output for both programming and auto-reverse purposes, with a DPDT switch selecting either the reversing loop or the programming track to be connected to the secondary outputs. The functionality for the secondary track output is selected in the JMRI profile.

    SPROG also is still developing a USB interfaced product with the Pi SPROG 3 Plus features. Note that the Pi SPROG 3 Plus, like the Pi SPROG 3v2 is an expansion "hat" board for Raspberry Pi model 3 or 4.

    However, as you can see, in the six months since I posted the original message, nobody had responded until now. Apparently the feature is not that appealing.
     

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