DCCNext

The next step in decoding DCC has arrived!

Available from now: the new Arcomora DCCNext DCC decoder!

What is it:

A single pcb that combines an Arduino UNO and the existing Arcomora DCC/Power shield.
It is a DIY kit that you have to solder yourself.

It contains:

  • Internal power supply. Input: 9-16V  AC or DC
  • Can also be powered by DCC
  • Can also be powered by external 5V.
  • Input for DCC with led indicator  and decoder circuit
  • ATMEGA328P processor
  • 16 Outputs or inputs for controlling accessories and servo’s.
  • Outputs with Dupont pins (for servo’s) or screw terminals
  • Separate 5V input for servo’s connected to Dupont pins
  • Additional 5V output for testing purposes (no servo’s) or leds
  • Status led
  • Power led
  • Servo power led
  • Reset switch

To keep the price low there is no USB interface on the board.
But an external USB interface(CH340) is also available.
It can be used for multiple DCCNext decoders.
So you need only one!
That saves money.

You can also use a FTDI interface if you already have it. But take care of the order of the connection pins!

Also available is a housing box for a more  protected mounting.

Connections:

Usage:

  • You can create your Arduino sketches for processing  a  DCC signal and upload them to the DCCNext.
  • Upload the Mardec 6.1 sketch for use as multipurpose DCC decoder for accessories and servo’s.
  • Upload the  ArSigDec 3.1 sketch for use as signal decoder.

The board has four power options:

  • Internal. Circuit powered by internal power
  • DCC track signal
  • External. Circuit powered by the 5V terminal
  • USB from PC

The power source can be set by two jumpers.

Interested?

You can make a reservation for:

The DCCNext decoder DIY kit. Contains the pcb and all components. Price: €8,75

The USB-Serial interface including a cable.
Price: €2,95

Type: CH340

A box with text stickers. Price: €4,50

Or a combi-set of all three parts. Price €15,90

You can also order a completely assembled DCCNext with interface and box.
The print is already soldered and tested. In the Remarks field of the order page you can specify which ports requires Dupont pins for servo’s.
Just connect to your PC and upload Mardec or Arsigdec or your own sketch.
Price only €26,95

Click here to go to the reservation page

53 thoughts on “DCCNext”

  1. Hello Nico,
    In the dutch “Montage handleiding DCCNext” i see a LED between pin 3 and 4 of the 6N137. In all other schematics i know of there is a 1N4148 in that place. Is the LED indeed functioning the same as the 1N4148? Futhermore is the 220 pF capacitor placed between pin 2 and 3 of the 6N137. In the DDC circuit shown on page 7 of arsigdecmanualdb.pdf there is a 100 nF capacitor between pin 8 and GND. Can you explan the different choice to me?. Can I build the DCC circuit part as shown in the DDDNEXT diagram als a saperate single board as well?
    Thnks in advance for responing.
    Greetings, Chris de Groot

    1. Hi Chris,

      Yes the led functions the same as a 1N4148, so don’t worry.
      Do you really think that I would sell it if it doesn’t work?
      The 220pF capacitor also occurs on other schema’s of the DCC circuit.
      Capacitor C4 of the DCCNext functions as the 100nF on the DCC/Powershield.

      Nico

      1. Hello Nico,
        Thank you for your answer. Ofcourse I know it works, but I am not that experienced in electronics. I just wondered, and liked to know.

  2. hello Nico

    I have built 2 dcc next decoders.
    one configured as a mardec, the other as arsigdec
    They both work fine, without any problems at all
    Thank you

  3. Hi
    Concerning the CH340 module. Do you use the DTR and the CTS signals on the board or are the just unconnected?

    1. Hi Tomas,

      As you can see in the schema of the assembly manual (download from download page!) the CTS is not used and the DTR is connected.

      Nico

      1. Hi Nico
        Thank You for your help. I didn’t see, there were a schematics included in the assembly manual. But the pinout int the schematics doesn’t comply with the pinout on the assembly. RX/TX is placed different.
        In the schematics, it is: GND, RX, TX, +5V, NC, DTR.
        In the assembly drawing, it is: GND, CTS (NC), +5V, TX, RX, DTR

        I suppose the assembly is the correct one?

        BR
        Tomas

        1. Hi Tomas,

          You are right.
          I fixed the manual already a few weeks ago. But apperently I forgot to upload it.
          Done now.
          Thanks

          Nico

  4. Hi Tomas,

    The file was replaced indeed. May be your browser picked it from the cache
    Clear cache and try again.
    You can order the CH340 interface by me or buy it at Aliexpress.
    Search for: CH340 micro USB

    Nico

  5. Great – Much better now 🙂
    I found the board at Ali’s at $1.20 🙂

    BR
    Tomas

  6. Hello Nico, this is a very interesting development. My layout currently has over 70 servo operated turnouts using hard wired control panels feeding into servo interface boards. It works fine, except for a lot of wire. I’m currently expanding with another 20 turnouts and DCCNext has the potential to be useful. I use the NCE DCC system.
    Just to clarify, I understand this board is essentially a multi channel accessory decoder. Using it to operate a turnout, please confirm I would need to generate a DCC accessory command from either the throttle, or a PC running JMRI or similar, or an encoder such as a Cobalt Alpha.

    regards
    Darryl

  7. Hi Darryl,

    Yes, the DCCNext requires indeed a real DCC command as specified in the NMRA specifications.
    However accessories and servo’s can also be controlled by a switch connected to a port that is set as an input.

    Nico

  8. Hi Nico,
    Am I right in thinking that a servo can only be operated one way by a switch connected to a port that is set as an input. I say this as on page 6 of the Mardec manual under Input Commands you say, “Nothing happens when the pin is made ‘high’ again”.
    Thanks, Ted

    1. Hi Ted,

      That applies only to Mardec versions prior to version 5.
      To rotate the servo back again the input must be made low a second time.
      But Mardec 5 offers more options. Look in the manual:
      An input can be activated in three ways.
      1) By lowering the input. Nothing happens when the entrance becomes high again. (type D)
      2) By making the entrance high. Nothing happens when the entrance becomes low again. (type U)
      3) By making the input low or high. The accessory or servo “follows” the input signal as if it is controlled by DCC. (type L)
      With this option, for example, a switch can also be converted by means of a switch.

      With options 1 and 2, an input acts as a momentary switch.
      With option 3, an input acts as a changeover switch. Just like a DCC command.
      The activation method is requested when configuring a port as input.

      Download the latest version of the manual!

      Nico

      1. Thanks Nico,
        That’s wonderful. I’ll download the manual now.
        Cheers, Ted

  9. hallo
    is het mogelijk om elke poort te configureren als in of output?
    dus is het mogelijk om ze door elkaar te gebruiken.
    mvg
    Jan Hendriks

    1. Hallo Jan,

      Ja, je kunt met Mardec van iedere poort een input of output maken.

      Mvg
      Nico

  10. Dag Nico,

    Wat is de reden dat de DCC Next zijn instellingen kwijt raakt. Dat is mij deze week al twee keer overkomen. Ik heb de gegevens natuurlijk wel bij de hand maar het wel weer een aardig klusje om al de instellingen voor de servo’s opnieuw in te voeren.

    Gr. Jan

  11. Hallo Jan,

    Geen idee waarom dat kan. Probleem niet eerder gehoord. Het lijkt erop dat het EEPROM niet helemaal goed (meer) is. Heb je dit vanaf het begin of is het pas na een tijdje fout gegaan? Heb je nog een andere DCCNext? Verwissel dan eens de processoren.
    Is de voeding helemaal in orde? Geen spanningspieken of zo bij inschakelen?

    Nico

    1. Hallo Nico, goed idee om de processoren te verwisselen, ik heb nog een DCCNext liggen.
      Voor zover ik weet zijn er geen spanningspieken.
      De andere Mardec en de Arloco functioneren prima en houden de instellingen vast.

      Wanneer jij nog niet eerder van dit probleem hebt gehoord zal het een toevalstreffer zijn.

      bedankt voor je reactie,

      mvg Jan

  12. De DCCNext is een mooi stukje techniek dat mij, als starter in de digitale modelspoorwereld, alle functionaliteit geeft die ik maar kan wensen.
    Als “herintreder” in deze mooie hobby wilde ik me concentreren op het bouwen van gedetailleerde landschapjes waar aanvullend de treintjes volledig automatisch doorheen tuffen. Door dit product te gebruiken hoef ik me niet meer te verdiepen in, voor mij, nieuwe programmeertalen en alles wat daar omheen hangt.
    Je moet uiteraard wel kunnen solderen. Een soldeer-station met instelbare temperatuur en een dunne soldeertip is geen overbodige luxe. Maar aan de levering van het product zal het niet liggen. Alles is keurig verzorgd en zeer gedetailleerd beschreven in begrijpelijk Nederlands.
    Een paar uurtjes solderen, software laden en de servo’s aansluiten en alles functioneert in één keer. Zelfs de goedkope servo’s van 0,90 euro per stuk via AliExpress voldoen prima voor de wissels die ik ga gebruiken.
    Ik kan dit product dan ook iedereen aanbevelen. Voor weinig geld heb je een perfecte dcc-wisseldecoder.

  13. Hallo Rob,

    Je praat hier over een wisseldecoder waarmee je servo’s gaat aansturen. Kan ik dit ding ook gebruiken voor het aansturen van bijv Fleischmann wisselaandrijvingen?

    Mvg Ron

    1. Hallo Ron,

      De DCCNext zelf kan niet zoveel. Het zit ‘m in de software die je er op laadt.
      Om wissels om te zetten gebruik je het gratis programma Mardec.
      Daarmee kun je wissels met servo omzetten maar ook met wisselspoelen.
      Maar er kan nog veel meer mee.
      Bekijk eens de handleiding van Mardec. Te vinden op de download pagina

      Mvg
      Nico

      Bekijk eens de handleiding van Mardec

  14. Very good and cheap dcc decoder.
    After i find out that the oscillator was broken and i changed it, so it seems to work.
    But i have some problems. I can’t use power option 2 if i try to use it, while i try to program servos the USB connection get lost or the decoder where reset. Only power option 1 works.
    After power off and than power on again, all servos would be set at 90°, but it seems that the atmega saved the correct position, but he is not set it correct.
    Maybe there is more broken than the oscillator?

    1. Hi Marco,

      I assume you have set the jumper to the servo position?
      Normally it should not be a problem to both connect USB and the Servo power.
      They are separated by the diode 1n5817.
      May be that diode is also not OK? I assume it is soldered in the correct position.
      Try to put another diode in parallel. The type is not so important. E.g. a 1N400x

      Nico

  15. Hi Nico,
    I’ve had great success using ArCoRoMa for both control of my signals and servos.
    I’m now trying to use DCCNext to drive bi-coloured LEDs to indicate routes set by a Digitrax DS64.
    Within Mardec, one aspect of the bi-coloured LED is set up with a DCC address and the other uses a buddy port.
    I’m using Power Option 1 (Internal) but with no “5V in for Servo” as I’m only driving LEDs.
    The DCC addresses are included in the DS64 routes.
    The problem I’m having is that the LEDs don’t always change as they should. I’ve tried it both with the DCC input linked to the track and also to RailSync from Loconet. When I use a throttle the LEDs always respond correctly.
    I’ve monitored Loconet and the signals are definitely there.
    Is there a better way to approach this, or am I doing something wrong?
    One thing, I was a bit surprised that I didn’t need resistors to limit the current on the LEDs.
    Cheers, Ted

  16. Hi Ted,

    I also use bi-colour leds on my demotrack. I use even two, one for ech direction. They toggle between red and green to indicate the direction that is set.
    They are configured as mode 2 (double steady).
    The address must be the same as the address of the switch.
    I assume that if the DS64 is setting a route that it sends out all DCC addresses of the switches involved in that route.
    I don’t see any relation with LocoNet. But I know nothing about a DS64.
    I found this:
    https://www.digitrax.com/tsd/KB799/ds64-setting-up-routes-with-ds64/
    and
    https://www.digitrax.com/tsd/KB798/ds64-how-to-run-a-ds64-route/
    I guess the problem is somewhere in the way the DS64 sets the switches.

    Nico

    1. Hi Nico,
      The routes I have designated each depend on a number of switches/ turnouts/points, hence the LEDs wired to the DCCNext have different addresses to the turnouts. I have included these different addresses in the DS64 routes, along with the turnouts in order to generate the appropriate DCC signals. The DCC signals for the LEDs appear to have been generated by the DS64 – I see them on the JMRI Loconet monitor.
      I’m still experimenting with ways around the problem.
      Cheers, Ted

      1. I assume each bi-colour led is linked to a specific switch and each switch has its own address.
        You don’t need to specify separate addresses for the leds.
        No need to define them in the DS64. Just configure them in Mardec with the same addresses as the corresponding switch.
        That’s all

        Nico

        1. Hi Nico,
          The LEDs denote which of the three yard tracks the switches are set to, not necessarily specific switches. One of the yard tracks can be linked to one specific switch and I’ve adopted your idea of using the same address for the switch and LED. The other two yard tracks rely on the position of two switches.
          I’ve now managed to overcome the problem by issuing multiple commands for the LEDs in the route – the logic being if it fails to respond to the first command perhaps it will respond to the next. Digitrax DS64 decoders can take up to eight entries.
          It’s difficult to understand why the problem arose – the LEDs always respond perfectly when the commands are issued by a throttle.
          Cheers, Ted

  17. Hi Nico,
    I’ve managed to update my software from 6.0 to vers.6.1 on my pc which is runs a 64bit operating system but am having trouble updating my laptop and tablet which both run a 32bit operating system. Is this likely to be something I’m doing or something in the software, please?
    As an aside, I’m finding the DCC Next excellent and have used the two Loconet wires in the Digitrax Loconet lead to feed the DCC Next(s) on my latest project. I may even go back and rewire my previous boards in this fashion.
    Cheers, Ted

    1. Hi Ted,

      There was indeed a problem with installing the Arcomora software on Windows 32bit systemen.
      This is fixed now. A new installation package is available from the download page

      Nico

  18. Hi Nico,
    I’m trying to get four points, each with different DCC addresses, to operate with the push of one button.
    The Input section of the Mardec manual states, “You can specify the address of another Input port as a 2nd or 3rd address! This allows you to start a whole range of actions”.
    I’ve created an Input port with a DCC address of 999 and specified 999 as the 3rd address of another Input port but the Input port with address 999 does not get activated by the first Input port. Have I misunderstood something?
    Cheers, Ted

    1. Nico has informed me that the statement, “You can specify the address of another Input port as a 2nd or 3rd address! This allows you to start a whole range of actions”, has been removed from the Dutch manual as this function was never developed – it has yet to be removed from the UK manual.
      I’ve now given the four points the same DCC address which achieves the same objective.
      Thanks, Ted

  19. Nico,
    Can I use the DCCNext with a Roco (Fleischmann) multimouse and a Z21_Start (DCC)system?

    1. Hi Willem,

      Yes you can. The Z21 uses also DCC to control trains and accessories.
      If you mean the black Z21 you can also use an ArLoco.

      Nico

  20. Hello Niko
    Thank you for sharing this software and the hardware kits. I enjoyed the process of putting the dcc next together and the skill building I gained through this process. I was able to plug it into the computer and install the Mardec software, all fine. I then set up port 5 as an accessory to turn on/off a LED. I connected the DCC input, and it indicates that there is a signal. My newbie question is; how do I wire up the LED that I want to be controlled by the DCC Next? I have the positive side of LED connected to a resistor and this is connected to port 5, where do I connect the ground of the LED to?
    When I cycle the accessory in my ECOS (with the address same that I set up on both), there is no indication in the DCC Next in the normal mode that port 5 is switching on or off.
    I use an ECOS as my controller and Rocrail as the computer software.
    Thanks,
    Kai

    1. In the manual is a large picture that shows how to do that. One side with a resistor in a port and the other side must be grounded.
      There are two ground terminals on the DCCNext.
      What accessory mode did you use for port 5?
      Does it fail already when using only the Ecos or when using Rocrail + Ecos?

      Nico

  21. I successfully got my dccnext yesterday thank you very much 😊
    It works like a charm

  22. Nico,
    Can I use then 5v output from a DCCnext print for powering relais prints (those from Ali) ?
    The DCCnext wil be powered internaly en the relais wil be powered with seperated 5v power supply.

  23. Hi mr. Kramer

    It is not advised to power relais or servo’s with the 5V output of the DCCNext or DCC shield. That is intended for low power devices like leds.
    Use a separate 5V Power supply for servo’s or relais. On the DCCNext you can use the servo power input when using Dupont pins

    1. I Understand.
      I have messured the current needed for one relay by 5 volt and it is about 80 mAmp.
      So using 6 relays the max current would be about 500 mAmps. much to much for the 5 volt output!

      Thanks again.
      P.Kramer

  24. Hoi, dank om jullie project te delen.
    Kan een marklin mobile station 2 de DCCnext aansturen?
    Ik zou hem willen gebruiken om wissels met spoel via mosfet aan te sturen.

    Mvg
    Peter

    1. Hallo Peter,

      Ja het mobile station 2 kun je gebruiken met de DCCNext.
      Maar uiteraard wel het DCC protocol gebruiken.

      mvg
      Nico

  25. hallo Nico,
    als ik de inputs van een andere arduino wil aansturen, waar moet ik de GND dan aansluiten?
    mvg,
    Michel

    1. Hallo Michel,
      Je hoeft alleen maar de GND van beide Arduino’s te verbinden.

      Nico

  26. Hello Nico/all

    Is it possible on the same DCCNext decoder to have some ports set up as signals (Arsigdec) while one/some ports are set up as servo (Mardec) ?

    Thx

    Jarle

    1. With Mardec you can only control signals with two leds. (e.g. red and green)
      Use the double steady mode.
      For more complex signals you must use Arsigdec.

      Nico

  27. Interesting things happening with my DCCNext which I’d thought I’d share.
    I’d set my up DCCNext to be a stand-alone accessory decoder to control Servos and associated frog switching relays. Control is by push buttons as described in the manual. I’m using Power Option 2.
    There is no input to the DCC input terminals as turnout control is by push-button only.
    However, sometimes when I get a short on another part of the layout a turnout controlled by the DCCNext throws. If I wire up the DCC Input terminals to Loconet Railsync the problem ceases. It doesn’t appear to cease if I wire the DCC Input to the track supply. Anyway, that’s my current solution to the problem and I hope it’s useful if others encounter the same.
    FWIW, Ted

  28. Hi Ted,
    Very curious that a turnout throws as a reaction to a short somewhere on the track.
    Also curious that a connection to LocoNet Railsync solves that problem but the DCC track output does not.
    Anyway you solved the problem.
    But many people may not have LocoNet Railsync.

    Nico

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