DIY DCC Decoder

Leo Bicknell Oct 23, 2023

  1. Leo Bicknell

    Leo Bicknell TrainBoard Member

    I posted about this a few months ago, but I figure it's time for an update. I've been slowly working on a project to build an open-source hardware & software decoder. It's progressed slowly, as it's just me in my spare time right now.

    The hardware/reference/Breadboard-1 design should be about "finalized" in that I'm ready to order some boards. This is my original PIC18 based design.

    There is corresponding software/reference/Breadboard-1.X which implements a very basic decoder. It programs on the main, stores CV's, can do consisting, NDOT, the usual basics. It even has a first swag at some very basic lighting effects. Motor controller code is simple, but functional.

    I also created a hardware/reference/Breadboard-2 design based on an STM32 processor. I haven't tried to make software work for it yet. About 90% of the software should be a direct port.

    There are a couple of very much draft real decoder ideas, they all need improvement.

    Roughly my next steps are to get some of the hardware boards ordered, expand/improve the lighting effects, and get some real motors connected to tweak the motor code. That last bit will probably require implementing the speed tables as well.

    As always, I'm still looking for others with the skill and interest to help.
    Hardcoaler, Curn, Mark Ricci and 2 others like this.
  2. Curn

    Curn TrainBoard Member

    Wow, when I first saw the title I figured you found a way to use some existing open development board as a mobile decoder for a larger scale or something like that. Your board designs are much more advanced than that and starting out with N scale. Pretty cool!
  3. Leo Bicknell

    Leo Bicknell TrainBoard Member

    Yeah, it's become cheap enough that a hobbiest can order boards in small quantities using the exact same stuff as the big guys. If Digitrax/Lenz/Zimo can make it, so can we! The hardware is actually pretty easy, it's the software that gets complex in a hurry. Basic go/stop/headlight is not difficult, but things like BackEMF, or the lighting effects take a bit more creativity and planning.

    Theoretically I can even make boards smaller than the smallest commercial offerings I know about -- and more importantly make them in a variety of shapes. For N/Z folks trying to shoehorn into weird locomotives it could be quite helpful.
    Mark Ricci, Sepp K and BigJake like this.

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