A journal following the history, design, construction and operation of Bernard Kempinski's O Scale model railroad depicting the U. S. Military Railroad (USMRR) Aquia-Falmouth line in 1863, and other model railroad projects.
©Bernard Kempinski All text and images, except as noted, on this blog are copyrighted by the author and may not be used without permission.

December 13, 2018

It's Alive!

Tom Pierpoint helped wire the first telegraph station today. Most of the process was straight forward, but we did encounter some curveballs.  Tom had ordered some jumper cables from Adafruit. They were nicely made, but the female end did not fit securely on the posts of the rotary switch. So I had to solder each connection, instead of simply pushing each one on.

First wires to be attached
Also, we had some confusion on how to wire the train numbers to the rotary switch. The Arduinos can handle 11 inputs. We  need to be able to OS train numbers 3-12, but we also need train number 1 to program the station number into the Arduino. That is because the Arduino uses the rotary switch settings at start up to set the station location. We think we sorted it out by making train 12 on the panel actually be train 1 to the Arduino.  We'll see if that works.

After Tom left, and we had a dinner break, I went back through the documentation for the tenth time and finished the final wires. Sure enough, I got the system to work. All train numbers except 6 work properly for regular and extras.

When I select train 6 and push either switch, the small LED on the back of the Arduino flashes, indicating it got a signal, but the message doesn't start playing. The wire connections appear good, so it might be a software issue.

Fully wired with some test leads to the sounder
Another glitch is that the reset procedure is not working. This station was set to Brooke, probably because we had the rotary switch set to 2 when we fired it up. It should be Aquia Landing. Stephen suggested that I reset while repowering and that worked. The station now has the correct station code. Yeah!  But now 5 is sending Train code 6 and 6 still doesn't work. Oh well, it's getting closer.

We still need to build 4 more station panels and the dispatcher desk, so lots of work to go but, so far I am pleased with the system. This is US Army Dot Code, a simplified version of Morse code adopted by the US Army during the civil war to allow new operators to be trained quickly. It was easier to learn than RR Morse, but did not allow messages to be sent as rapidly as regular railroad morse.  We have the speed set so that it sends messages slow enough, that even a new operator can take down the dot code, and then translate the messages with a cheat sheet.  Perhaps, now we can have a dispatcher job position on the RR. It won't be the most exciting job, but it will be a change of pace. And everyone else in the layout will enjoy the sounds of the telegraph clicking away.


  1. That's a great application for the Arduino Bernie and thanks for posting it.

  2. This is very cool Bernie. It will further add to the layouts period atmosphere. Thanks for sharing.