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Recommendations on JMRI and signalling systems

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  • Member since
    May 2019
  • 4 posts
Posted by KenJ01 on Tuesday, May 21, 2019 6:03 AM
Mel, I have since proven the basic algorithms for signal control and array's for turnout status and train occupancy detection. Now need to revise the software for live data detection and reaction. Ken
  • Member since
    May 2019
  • 4 posts
Posted by KenJ01 on Monday, May 13, 2019 7:42 PM


Thank you for showing interest.  I have yet to obtain any signals but I expect I will build my own searchlights - I found a good article online on how to do that - far cheaper than they could be bought.  For my own system I am looking down the track to about 80 signals, 35 occupancy detectors and 24 turnouts  and like you linked through a truth table.  Right now I have got a simple UNO based sketch that will provide Red, Green and Amber lights via PWM of a RG tri-lead LED.  Robin Simonds has a good article on train occupancy detecton using firstly ACS 712 current sensors which are less than AUD$2 each and then he used a more sensitive coil transformer (  Simonds moved to the coil transformer because his N scale did not draw enough current at idle to register, I have some ACS 712's which I will test on my HO system to see if they work - if not I will try the coil transformer (again only a few $ each).

I am ambivalent on the LEDs as I can adjust the PWM to get the colours that I am happy with. I bought them on eBay for $5 for 50.

For the Turnouts I will link via a simple resistor circuit to the spare relay in the tortoise motor to provide a HIGH / LOW response to my system.

At the moment I have just proven my concept and intend to work on the detection of the various sensors and then use that to adjust an array.


  • Member since
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Posted by RR_Mel on Monday, May 13, 2019 9:04 AM

I’ve been piddling around using an Arduino MEGA to control my 8 block signal system for awhile, looks pretty good right now.  I went with a simple Truth Table to operate the signals and each signal is free floating, occupancy in the primary block is red and the advance block is yellow no occupancy it either block is green.
I currently have a working 8 block system for one direction, if that works OK I’ll go with my reverse direction plan.
I currently have a Rob Paisley controller that has worked perfect for many years.  It started out using his current detectors but I’m not one for liking resistors on the wheels so I cut over to IR beam detection about three years ago.  I really like the IR detection.  On this go-round I’m planning on using the Arduino FC-51 IR detector (reflective) because of the price.  The FC-51 is 50¢ on eBay and 50 for under $20.  They don’t have the advertised range of 11 inches, reliably 3½” to 4” but for between the ties they work great.
I use SP type signals, single head three color searchlight.  I tried dozens of 3mm bi-color LEDs and wasn’t happy with any of them and finally found the SMTL4-RGY LED and it works perfect and the yellow is more amber than yellow, perfect!!!
My Model Railroad   
Bakersfield, California
I'm beginning to realize that aging is not for wimps.
  • Member since
    May 2019
  • 4 posts
Posted by KenJ01 on Monday, May 13, 2019 6:32 AM

Hi, I have similar concept for my adhoc system but have been looking at using an arduino-based system.  Robin Simonds "TheNScaler" has some great ideas but his programming skills leave me for dead.  I have taken a simpler approach based on his concepts and am just protoyping the software.  Harware via ebay is very cheap, for example cccupancy detection modulefor under AUD$3.  I am interested contacting anyone wo is exploring this approach.  

  • Member since
    February 2002
  • From: Reading, PA
  • 28,011 posts
Posted by rrinker on Thursday, April 25, 2019 3:54 PM

 There are two types of signaling systems - the 'smart' ones which requre you to program a whole raft of CVs to create the logic (ie, signal 11E Red if turnout 12 reverse or block 10 occupied, signal 13W yellow if turnout 14 normal and block 8 occupied) or 'dumb' ones that just set the signal indications to whatever you tell them to, and need something else (ie, JMRI to do the logic - figure out what signal to set to what aspect based on status of blocks and turnouts).

 TO some, they hate having to have a computer and doing it the second way. But - this is the more flexible and, in some cases, easier way. JMRI has the facilities built in to do this logic. 



Modeling the Reading Railroad in the 1950's


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  • Member since
    October 2006
  • From: Western, MA
  • 8,375 posts
Posted by richg1998 on Thursday, April 25, 2019 2:11 PM

It has been some years since I used JMRI but here is a link you might like if you have not looked into it much. More than I care to do. I did some Google searching out of curiosity. It has been a while.


If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    February 2004
  • From: Out on the Briny Ocean Tossed
  • 4,219 posts
Recommendations on JMRI and signalling systems
Posted by Fergmiester on Thursday, April 25, 2019 9:58 AM

I’m in the process of ”upping my game” and hope to install a signal system (Canadian National circa 1960) on my layout. It was recently suggested I look into the JMRI sites for ideas and direction. There’s a lot there and would like some recommendations. I operate IOS.

Tags: JMRI , Signals

If one could roll back the hands of time... They would be waiting for the next train into the future. A. H. Francey 1921-2007  

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