Simple, Cheap, Auxilliary Decoder - Is there such a thing?

[PupCam]

Hi,  I'm playing with an idea that will need numerous, independent but very simple decoders each with effectively just 2 or 3 digital channels/outputs.   The emphasis is on cheap ....

 

Is there such a thing?

 

Thanks in anticipation!

 

Alan

[WIMorrison]

Lais Decoder, just don't use the motor outputs - you may need to put a resistor across the grey/orange to simulate a load.

[Nigelcliffe]

Make your own ?  Paul Harman published a design many years ago which makes up to either an accessory or function decoder on stripboard.  Comes in at a couple of pounds each. 

[Ron Ron Ron]

Are these to go onboard model rail vehicles (locos or other rolling stock) ...i.e. function only, mobile decoders....

..or for use trackside, to operate layout functions (accessory decoders) ?

 

There are dedicated function only decoders for use on trains/ locos/ rolling stock etc, or a normal, cheap decoder can be “adapted” without using its motor drive outputs.

 

Trackside, there are dedicated decoders for things like operating lighting effects, signals, operating servo driven features and general switching duties.

 

 

.

Edited May 8, 2021 by Ron Ron Ron

[WIMorrison]

Here is a link to the 860011 LAIS 4 x Function only decoder which is $15 or around £10 = £2.50 per function

 

Function Only Decoder for Lights Control Without Orange&Grey Wire

 

A Google search will throw up UK Suppliers also.

 

 

[PupCam]

1 hour ago, Ron Ron Ron said:

Are these to go onboard model rail vehicles (locos or other rolling stock) ...i.e. function only, mobile decoders

Indeed they are hence the desire for cheap.

 

[PupCam]

1 hour ago, WIMorrison said:

Here is a link to the 860011 LAIS 4 x Function only decoder which is $15 or around £10 = £2.50 per function

Thanks, I did have a quick squint with the aid of Mr Google but ~£10 for each module  is (ideally)  beyond the desired unit cost - what a cheapskate I am!

[PupCam]

2 hours ago, Nigelcliffe said:

Make your own ?  Paul Harman published a design many years ago which makes up to either an accessory or function decoder on stripboard.  Comes in at a couple of pounds each. 

Do you have a working link to a page/website with all the necessary info.   

 

My Googling only leads me to the defunct page   http://dccdiy.org.uk/  which is a bit of a tease!

 

Although his forum still seems to work ....

 

https://diydecoder.proboards.com/

 

Thanks

Edited May 8, 2021 by PupCam
Added link to forum

[PupCam]

As it's an old site presumably things have moved on and it is no longer supported.

 

But .......

 

Go in one level down and the website can be navigated and useful stuff "got at"

 

https://dccdiy.org.uk/function.html

 

Looks very interesting, I feel yet another little project coming on.

 

 

Edited May 8, 2021 by PupCam
Expanded

[NIK]

3 hours ago, PupCam said:

Hi,  I'm playing with an idea that will need numerous, independent but very simple decoders each with effectively just 2 or 3 digital channels/outputs.   The emphasis is on cheap ....

 

Is there such a thing?

 

Thanks in anticipation!

 

Alan

Hi,

 

So you wanted us to guess what your idea of cheap is?.

 

As is often the way with other questioners if you could say what your requirement is then folks can save their time and energy and focus on what you are after.

 

Regards

 

Nick

[Nigelcliffe]

36 minutes ago, PupCam said:

As it's an old site presumably things have moved on and it is no longer supported.

 

But .......

 

Go in one level down and the website can be navigated and useful stuff "got at"

 

https://dccdiy.org.uk/function.html

 

Looks very interesting, I feel yet another little project coming on.

 

 

 

Good, you've found it.    The design works fine, I built a few many years ago. 
Its probably only cost-effective if you have the ability to load code into PIC processors.  Otherwise, its likely to be as cheap to buy the cheapest manufactured loco decoders and use those as function decoders. 

 

 

For accessory decoders, there are numerous designs around Arduinos which work.  I'm sure the code in those could be changed to function decoders without much work, but making one physically small enough for use inside stock may be too much work. 

 

 

- Nigel

[PupCam]

29 minutes ago, NIK said:

Hi,

 

So you wanted us to guess what your idea of cheap is?.

 

As is often the way with other questioners if you could say what your requirement is then folks can save their time and energy and focus on what you are after.

 

Regards

 

Nick

Apologies for my lack of clarity in my first post, I'll consider myself told off and I'll try harder next time not to waste your time next time.     

 

Many thanks to Nigel, that is exactly the sort of thing I wanted to know and with a bit of persistence I've managed to access the relevant material 

 

Thanks also to WIM for taking the trouble of providing your suggestion even though it wasn't quite the solution I was after. 

 

The fact that I will have to build the decoders myself is not a problem and is indeed quite appealing (I've already built the DCC++ unit and will be working on my own style of User Interface at some point) and the investment in a cheap PIC programmer will be just that, an investment.  I wouldn't want to "waste" all the functionality in a full spec. loco decoder if for no other reason than the high unit cost if I ultimately end up needing 30 or 40 decoders.

 

Thanks once again for all your constructive comments.

 

Alan

 

 

Edited May 8, 2021 by PupCam
Typo

[Sir TophamHatt]

4 hours ago, PupCam said:

Apologies for my lack of clarity in my first post, I'll consider myself told off and I'll try harder next time not to waste your time next time.

 

No need to apologise.

Sometimes being a little vague gets you the answers and teases out other solutions you may not have thought of.

[NIK]

1 hour ago, Sir TophamHatt said:

 

No need to apologise.

Sometimes being a little vague gets you the answers and teases out other solutions you may not have thought of.

Hi,

 

No need for apologies but as a vague question could result in a lot of people doing fruitless work why not focus on what you want?. You have mentioned there is a desired unit cost but have yet to say what it is.

 

You've hinted you might want 30 to 40 decoders so that's a start. Now how much can you afford to spend on each decoder?.

 

A possible clue: a low cost decoder with present technology needs a microcontroller unit (MCU) at its core. MCUs can be had from a few pence up to £10 sterling or more.

 

As you have mentioned they have to be programmed and the cost and ease of programming varies tremendously.

 

Another variable is the physical size of the decoder - have you got the space for 150% of an  Arduino Nano clone for example?.

 

Regards

 

Nick

[Signalist]

15 hours ago, PupCam said:

Do you have a working link to a page/website with all the necessary info.   

 

My Googling only leads me to the defunct page   http://dccdiy.org.uk/  which is a bit of a tease!

 

Although his forum still seems to work ....

 

https://diydecoder.proboards.com/

 

Thanks

 

Sorry, I had not realised that the site had stopped working, I will get on to the webmaster and see what has gone wrong.

 

The forum is hosted seperately.

 

Glad that you are finding the resource useful.

[PupCam]

2 hours ago, Signalist said:

 

Sorry, I had not realised that the site had stopped working, I will get on to the webmaster and see what has gone wrong.

 

The forum is hosted seperately.

 

Glad that you are finding the resource useful.

Oh thanks that would be excellent!    As you can see, I managed by dint of cunning and persistence, to work round it but if the home page can be fixed I'm sure that would be of use to others in the future.   It certainly looks like very useful information and I'm lining up the wherewithal to have a go.

 

Just for "Debug" purposes this is what I see when I attempt to open the home page.  

 

 

 

When you do subsequently open it none of the links work as they are referenced to the  local copy of the page on the hard driver where, of course, they don't exist.

 

 

Edited May 9, 2021 by PupCam
Moved picture

[Signalist]

There is more than one site hosted on the same place, and I think there must be some interaction that has replaced the static homepage (index.html) with something dynamic.

 

I don't have access to the hosting so the stock levels have not been updated for years.

[aleopardstail]

space for an Arduino Pro Mini? would need an opto-isolator circuit and a power regulator & rectifier circuit to go with it but reasonably cheap and can drive pretty much any number of outputs if you are willing to add output shift registers or extra port multipliers - can do a decent number on its own though.

 

can also get the chips on their own (inc. the SMD ones if you can work with them, these are pretty small)

 

 

[PupCam]

On 11/05/2021 at 17:02, aleopardstail said:

space for an Arduino Pro Mini? would need an opto-isolator circuit and a power regulator & rectifier circuit to go with it but reasonably cheap and can drive pretty much any number of outputs if you are willing to add output shift registers or extra port multipliers - can do a decent number on its own though.

 

can also get the chips on their own (inc. the SMD ones if you can work with them, these are pretty small)

 

Space isn't generally likely to be a problem as the decoders are to be installed in O Gauge  rolling stock.    Each vehicle will only need a couple of digital functions  but there are a good number of vehicles potentially hence the desire to minimise the decoder unit cost. 

 

Nigel's suggestion of the hand -rolled Paul Harman design would seem to fit the bill perfectly so I'm going to give that a go  although I've just been distracted by the getting the new DCC++ EX software up and running.  Progress has been made in that direction but I'm not 100% of the way there yet.   When I do get round to building a decoder or ten I'll let you all know how I get on.

 

Anyway, many thanks for your suggestion.