Can an Accessory Decoder drive a digital display?

[dasatcopthorne]

Guys.

 

Our Club has an end to end DCC layout and for some time now I have been thinking of a way that the 'driver' at the dispatching end of the layout can send the Loco number to the far end 'driver'. The far end 'driver' would then take charge of the train for the whole journey. The dispatching end have no input to that loco at all except to send the number for the receiving driver to take action. (hope that's clear).

 

I know nothing about programming Arduinos and such stuff but I have just had a thought. Hopefully items needed could be bought reasonably on the WWW.

 

Could a 4 digit code sent to an accessory decoder be used by that decoder somehow to drive a 4 digit display and show that code number? (which would be the loco code.)

 

Any takers please?

 

Dave

[Nile_Griffith]

Guys.

 

Our Club has an end to end DCC layout and for some time now I have been thinking of a way that the 'driver' at the dispatching end of the layout can send the Loco number to the far end 'driver'. The far end 'driver' would then take charge of the train for the whole journey. The dispatching end have no input to that loco at all except to send the number for the receiving driver to take action. (hope that's clear).

 

I know nothing about programming Arduinos and such stuff but I have just had a thought. Hopefully items needed could be bought reasonably on the WWW.

 

Could a 4 digit code sent to an accessory decoder be used by that decoder somehow to drive a 4 digit display and show that code number? (which would be the loco code.)

 

Any takers please?

 

Dave

I'm guessing that you are trying to come up with some kind of bespoke small display to install at the end of your layout.... Perhaps...... ????

 

If you are might I suggest that you are over complicating things. I'm fairly certain that there is no direct/simple way to achieve your goal via DCC. But in the spirit of the Russians in the 60's space race, could I suggest something else. A Small laptop, a long VGA cable connected to a TFT monitor. A simple program like Microsoft PowerPoint would allow you to build a deck of slides (perhaps one for each loco) that could be shown on the remotely wired TFT monitor. The slides could carry not only the loco number but the name too. The trick is that PowerPoint allows you to access each slide in a deck directly by inputting the slide number directly on the laptop. So for example if slide number four has for example "53074 Squiddly Diddly" written on it, then by typing in the number four key and enter while PowerPoint is in slide show mode, the remote screen will show the slide for loco 53074. You could also have a slide titled "We are going for a brew!".

 

Just a suggestion.

[Tim V]

Or - you could get some white board markers, and write (!) the number on a board you hold up; what could be simpler?

[WIMorrison]

why not use bell codes like the prootype did to get arounmd this problem?

 

tech has its place, but that isnt everywher  

 

… and that is being said by a real techie!

[Gt.Shefford]

The easiest way to achieve this is to use a RailCom with a lenz LRC120 display. 

 

 

Jonathan 

[dasatcopthorne]

Thanks for all your replies gents.

 

Dave.

[Steven B]

Certainly do-able with an Arduino or two. There's a couple of approaches I could see:

 

1. A pair of Arduino, each with a keypad, LCD display and "send" button. User keys in loco number and presses "Send" - code is sent to other arduino via RS232, Ethernet or CAN bus for display.

 

2. Arduino sniffs packets from the DCC track feed. Using either an unused function number or treating the address as an accessory would cause the arduino to display it. E.g. doing Set accessory 1234 to thrown/active displays the number 1234. This wouldn't work so well if you have matchin accessory addresses and loco numbers.

 

Steven B.

[Crosland]

Could a 4 digit code sent to an accessory decoder be used by that decoder somehow to drive a 4 digit display and show that code number? (which would be the loco code.)

 

Yes and (more so) No.

 

The most you can send is a byte so you would need 2 addresses, each handling two digits if using hex to 7 segment decoders, or four address with a byte each directly driving the 7 segments. There are DCC packets defined to send arbitrary bytes rather than the more common addressing 1 of 4 turnouts.

 

The big problems will be finding a system that can generate the correct packets and a decoder to generate the outputs.

[Suzie]

If you are using something like JMRI already it should be quite straightforward to define some 10-aspect signal masts which will drive accessory decoders with 4-bit BCD output for each digit that can be connected to displays that take a BCD input. If you are starting from scratch there are probably easier ways to do it!

 

Here is an example of something that could be interfaced to an accessory decoder:-

 

https://www.ebay.co.uk/itm/4x-CWD-501-LED-digit-display-segment-BCD-8-4-2-1-50x80mm-5V-SN7447AN-/202339796048

 

A couple of 8-output DIY decoders would fit the bill:-

 

http://dccdiy.org.uk/accessory.html

 

Use the low power 8-output function decoder kits but with accessory decoder firmware

[dasatcopthorne]

OK.

 

Seems the Accessory chip thing won't work.

 

Could a small numbers-only key pad get an Arduino to display a 4 figure number on an LCD display. The key pad would need a key to clear the display.

 

What power supply is needed and is there any ready made software to achieve this please?

 

Dave

Edited July 5, 2018 by dasatcopthorne

[Mike Buckner]

How about a standalone 1-track shuttle beside the main layout, DC rather than DCC, diodes at each end to automatically stop the train at each end. Loco & One wagon. Write down the code (or have pre-printed blocks), place in the wagon, turn the controller to "far-end" direction. When you want the wagon back, turn the controller to "near-end" direction.

[fcwilt]

OK.

 

Seems the Accessory chip thing won't work.

 

Could a small numbers-only key pad get an Arduino to display a 4 figure number on an LCD display. The key pad would need a key to clear the display.

 

What power supply is needed and is there any ready made software to achieve this please?

 

Dave

 

Easily done if you are good with soldering and programming in the Arduino IDE.

 

The basic Arduino board, the UNO, runs on 6 to 20 VDC.

 

There are many add-on devices for implementing displays.

 

https://www.adafruit.com/category/63

 

Scanning a basic keypad is not a problem.

 

https://www.adafruit.com/?q=keypad

 

 

I don't know of any existing device that will do it all "out of the box" but if you''re good with the actual wiring any Arduino programmer could code the "sketch" in a day.

 

Frederick

[dasatcopthorne]

How about a standalone 1-track shuttle beside the main layout, DC rather than DCC, diodes at each end to automatically stop the train at each end. Loco & One wagon. Write down the code (or have pre-printed blocks), place in the wagon, turn the controller to "far-end" direction. When you want the wagon back, turn the controller to "near-end" direction.

 

We already use that.

 

I wanted something slightly better.

[smokebox]

You could have 4 rotary switches controlling 4 banks of LEDs. Set the rotary switches to the loco number and that number is displayed by the LEDs. Cheap rotary switches are available with 12 positions so you would have 2 blank, unused positions. This solution would require lots of wires though.

 

Could the cobalt alpha system offer an alternative?