if you have a larger layout where a number of occupancy detectors are required, your looking for something that is reliable, inexpensive and worry and maintenance free, buried under the layout.
I'm sure that the Arduino board could be replaced by an 8-pin Pic processor, but even such an implementation would be more complicated than a simple diode drop detector. Of course, such detectors aren't intended for DC.
but modelers interests also justify approaches ...
greg - Philadelphia & Reading / Reading
I gave it a read, interesting enough approach.
But for me current detection works just fine.
Signaling and detection are generally about mainline operation. I model an era when mainline trains had cabooses. Light the caboose, and the whole train is detected. Size blocks properly, and use overlapping sub blocks for interlockings. Light most passenger cars, especially tail end cars. No worries, current detection works fine.
I run my trains with DC, so it is also easy for me to monitor direction.
And my interlocking sub blocks also lock out turnouts so they cannot be thrown under a train - just like a real life interlocking plant.
All done with $3 relays rather than computers or processors.
I use Dallee inductive detectors, pricey but rock solid reliable.
And the Dallee detectors have dry contact relays on board as the heart of my signal system - that combined with spare contacts on relays used to operate turnouts, is a complete signal system - with no processors.
All with wireless radio throttles...........don't need no processors here......
Sheldon
Looks interesting. I will take a look. I generally prefer current sense systems that aren't point based, so you can exclude sidings, and adding cars in the middle will definitely be detected. There are definitely use cases where a point detection system is more usable, and perhaps a combination of systems will get the best fo both worlds - easy to tell direction of travel while no issues with things like setouts. A current sense system can do direction, but to do so it must track the status of each block, and also know the railroad, so that if it sees block 5 active and the next one active is block 6, and it knows block 5 connects to block 6, then something just moved from 5 to 6. Not as easy as just seeing which sensor was tripped, east end or west end.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Please let me know what you think of the system, and ask any questions that you have.....
Another interesting Arduino application.
Thanks crusader27529
Dave
P.S. I like the price for the plans. You can sell me as much of that as you want to!
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
I don't have anything to sell other than the idea, and that's free!
Occupied, obviously......once the train clears the block, just touch the block reset, and all is OK.
Conversely, the same environment, but an 0-5-0 operation ADDS a car with 4 axles.....when the train leaves the block, is it occupied or unoccupied???
The answer is unoccupied, because the logic prevents the count going below 0.
Look at the videos and read the docs on TrainBoard.....actually, I count anything larger than a minimum size, which is about 1/4 inch. The system actually ends up counting trucks because they only cause 1 transition through the sensors, but I just count any appropriate transitions, defined by the state machine logic.
I understand it perfectly......... I also have been around the block a whole lot of times.
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
What part of public domain don't you understand?
Sounds like we are being given a sales pitch. Isn't that against the Forum rules?
Local enters the block with and engine, 10 cars and a caboose, 48 axles. Stops mid block and sets out 1 car at an industry. Departs block with an engine, 9 cars and a caboose, 44 axles.
Is the block occupied or unoccupied?
Dave H. Painted side goes up. My website : wnbranch.com
I've designed and put into the public domain, a complete detection system that does NOT require any modification to any rolling stock or locomotives, and is independent of track power.
As such, it will work on DC or DCC or for that matter ANY form of power used for a model train. It's designed to be cheap and simple, yet reliable.
The system is Arduino based, and includes basic, simple signaling as part of detection, but if that's used is up to you. It supplies a simple logic level signal to indicate that a block is occupied.
The design was initially introduced on the TrainBoard forum, and I'm trying to get more exposure so more people will try it. There are videos and complete documentation that includes the code for the Arduino, schematics and single-sided PCB layouts so you can make the boards at home. There is also some technical details of how it works.
The estimated costs per block is between $9 and $16 depending on how fancy you get in the build process. The outputs are on 0.100 centers, so many types of connectors can be used, from simply soldering wires to the pads (not recommended) to simple pin headers, to screw terminals. The wiring to external devices is whatever you have around, and I use the wire from CAT5 computer cables.
Besides the Arduino modules, the only external components are resistors for the indicator LEDs, the IR sensor modules and the IR source LED and its current limiting resistor. Simplicity by design!
http://www.trainboard.com/highball/index.php?threads/different-way-to-do-detection.91951/
The video production isn't very good, and if you watch all 10, the final system implementation is worth it. Again, all the code and schematics and board layout is done, and the discussion should help you understrand how it works and how neat & reliable it is.....hopefully, you'll see what I mean and will give it a try.
I'll respond to any questions here and/or on TrainBoard.