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?