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Arduino, Hardware, Software

USB Configurable Arduino DDC Servo & Accessory Decoder – ArCoMoRa 4 – Configure and Tune Servos

servoIn the 2 previous videos we configured ports as an accessory. In this video we’ll have a look at how to configure a port to control a servo motor via a DCC address.

First, of course, we have to connect a servo to one of the ports. When we solder our DCCnext we can decide to have some Dupont pins on the PCB to connect our servos … very convenient.

Use a separate 5V power supply to feed your servos … it is not a good idea to power the servo motors from your USB connection. DCC next has screw terminals to connect the 5V servo power. This can at the same time power the Arduino circuitry (place the jumper accordingly, see the user manual).

To configure a servo port the steps are:

  1. Type C to enter config mode
  2. Type P and enter the port number
  3. Enter the DCC address we want this servo to have
  4. Type 2 to make this port a servo

By default the angles are set to 75 and 105 degrees. We probably will have to tune these angles to make our application work properly. With the + and – command we can change the angles by +/- 1 degree. To toggle between the two angles, type C (change).

During initial configuration we have entered a default servo speed, yet for every servo port this speed can be changed: type S and enter the speed.

With any servo, one or two additional ports can be appointed that switch together with the servo. This can for instance be used with electrofrog turnouts, to switch relays to change frog polarity. This will be the subject of the next video.

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7 thoughts on “USB Configurable Arduino DDC Servo & Accessory Decoder – ArCoMoRa 4 – Configure and Tune Servos

  1. Hi Rudy, I am having a problem downloading the “ArCoMoRa 4 – Configure and Tune Servos”. YTD indicates that it has downloaded the file, but, shows its size as 5MB, and the file does not show, and there are no errors reported. All other files have downloaded OK.


    Posted by Barry | December 1, 2019, 04:58
  2. Please can you explain how to connect DCCNext to DR5000 after the configuration of servos? Thank you


    Posted by Renato | September 11, 2019, 18:37
    • DCCnext is a DCC decoder … it is connected to the ‘Track’ output of the DR5000, or any other DCC command station. Usually the DCCnext’s are distributed over the layout and the input signal is picked up locally from the rails with 2 dropdown wires.


      Posted by RudyB | September 12, 2019, 08:40
    • Hi Rudy,
      since a few days I have changed my layout regarding TO switching with the Arcomora DCCnext Decoder.
      All is running like you also describe in the video. I have one issue only. If I get in contact with one pin only from my Digital Voltmeter to the Plus or Minus on the external 5Volt Power Supply (Voltage or Resistor position independ), the servos go to flickering and go out of stored position. This sometimes happend also when a loco has bad contact to the rail or if the loco drives over a turnout. Do you know this effect or do you have an idea to get this solved.
      I look forward for an aswer from you with your big experience of model railroad.
      Regards Hans


      Posted by Hans | October 7, 2019, 17:57

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