Author Archives: Simon

About Simon

Work out what you want, then get on with it.

DCC: getting long in the Bluetooth?

I thought that, ten and a half years after originally penning this, I would repost it.

Yes, there are now off-the-shelf solutions from the excellent Tam Valley Depot for both BT and wireless communications, but compared to the small thumbnail devices I see around, they are bulky. Granted, there is a need to combine this with battery charging/regulation and current step up, but there are small circuits available for doing this.


Thinking aloud, and knowing it is technically possible, but not sure how, how about an idea for the next stage in DCC?

Conventional control systems apply 0-12v DC over the rails, and any locos not isolated respond to this and they move. (Also multiple units, carriages and what have you, but I would like to keep this simple.) The rails supply power and control, as a single combined form of energy.
DCC has a constant AC voltage for power, and superimposes on this an encoded command signal which is received by all locos, but is ignored except by those to whom the command is directed. This is all done over two-rails, which serve the purpose of providing power and also of conveying the command.

Most wireless DCC systems remove the tether between the base station and the individual control units, but the loco still receives both power and control over the rails.

Now, there are some interesting alternatives, such as Locolinc and also CVP’s Airwire900. Locolinc is a proprietary system, and that’s about that, really. Airwire900 is great, but like Locolinc is not suitable for use in the EU/UK due to the frequencies it uses. They both have the right idea: battery supply of power and wireless transmission of the control signal. But if everyone turned up with one of these systems at a model railway exhibition, we might get haywire rather than airwire as I am unclear on how they pait the control units to the locos. Much closer to an ideal is the do-it-yourself approach of the Aussies, with the concept of DWiDCC (Direct Wireless DCC) but again, this is using radio frequencies. Both DWiDCC and Locolinc point out that one could use the track to provide a trickle charge for the on-board batteries – when it came to reverse loops one would simply have a dead section longer than the longest loco, and point crossing vees simply do not need wiring up at all. (And the power provided could double-up for track circuiting purposes.) These systems are all, in their own ways, brilliant and yet…

…and yet, why, instead of this direct-to-loco control via radio frequencies, can we not have a simple bluetooth setup?

What I have in mind, is an interface which plugs into my DCC command unit. This makes the base station a key unit with overall control (there could still be a programming tack or output if so required). Throttles can be tethered to this, or themselves could plug into a bluetooth transmitter unit. And for locos, a simple bluetooth receiver, into which power is fed from the batteries, and which superimposes the DCC command signal over this before feeding into any NMRA-compliant DCC decoder you care to think of.

If provided as a series of bluetooth components, for the base, throttles and locos (and accessory decoders – why not?) the system is independent of all others, and anyone can then turn their tied down system into something really revolutionary. With modern motors (not just coreless, Sagami and Mashima, for example, are efficient) and advances in battery technology, power is not an issue.

So, if anyone out there interested in DCC knows enough about blue tooth to make this work, please, please design a prototype and let us know about it!


Also, why not call it BCC, Bluetooth Command Control?

“Once you know, it has to be done”

The above is a wonderfully resonant quote from a model railway forum post.

It refers to the fact that the builder had made an assumption about a feature on his chosen prototype, but when he got around to checking up at his local club’s library, he found he needed to make some corrections. (This is a very minor example of the disruption caused by COVID-19, as he didn’t want to put the project on hold pending all the information.) Not everyone would have bothered, but that, perhaps, is the most succinct and compelling difference between a genuine “finescale” model-maker and someone who doesn’t want to get it right. I might add that wanting to find out these details is also a key part of the finescale approach.

There is also the point that pending full knowledge of prototype practice, a reasonable interpolation of the design was made – no hanging around waiting to “know everything”, just an acceptance that a correction would be made if necessary later. This applies to most things within our hobby, although once the track is laid, it can be difficult to change certain fundamentals of its design and construction without wholesale destruction!


To a picture of the Dukes of Hazzard, with Daisy sprawled over the car roof, a friend recently said:
“Back in 1979, the most shocking thing about this programme was how short those shorts were … “

This is my reply.

No, the most shocking thing was how unaware we all were about the offensive meaning of that flag.
The fact that we weren’t shocked back then doesn’t alter the fact that it was actually shockingly crass to large parts of American society. 

BLM is a movement aimed at getting American Society to the point where all lives matter equally, and to address the systemic racism that the majority of us simply don’t understand – witness some of the discussion points on this thread.

I am 100% against people making everything they can into an issue, particularly when it leads to a whitewashing of history (I chose those words deliberately, as it is the whites who are washing racially-based slavery out of history), and I am all for recognising the simple truth that for most of human history slavery has been the norm, but that doesn’t mean we can simply dismiss it out of hand: we need equity (the same fair chance at success, with help to compensate a little via things like free healthcare, free education), not direct equivalence (we are all different, and we start from different places: diversity and variation are surely to be celebrated?) No, we have to work at being better, and not hiding the past, but showing that we are continually improving on it.

For the record, my forebears are working/peasant class as far back as history records them. Almost certainly some were slaves, their descendants serfs, and later generations were hard working and poorly paid. Greater social mobility and educational equity meant my parents were the first in either of their families not to rent, I.e. to have a mortgage and eventually to own a house outright, and I was the very first to toddle off to higher education and get a degree. None of that is because I am white and (now) “middle class”, just the result of greater equity in our society. The same is also true for many of my BAME friends (most of whom shudder at being labelled that way) but they have had to overcome obstacles – including from amongst their peers at school – because of their skin colour.

That’s what BLM is trying to achieve: not the re-writing of history (see Nelson Mandela’s comments about things like Rhodes Scholarships) but greater sensitivity and the opening of doors rather than the closing of them.

I got off my soapbox, and gave it to the short kid. Unfortunately he fell off, and now I am being pursued by lawyers for an injury claim… 😉