The wide world of LCB's.

Layout Control Buses that is.

As with any efforts to produce standards, particularly open ones, their has been an attrition of projects in recent years. Layout Control Buses for model railroads are not new, but those that exist now are often based on simplistic and not greatly flexible schemes. Possibly the classic is Dr Bruce Chubbs C/MRI which first appeared in Model Railroader magazine in February of 1985. Based on a simple microprocessor module with an RS-485 or RS-422 interface, connected to a PC, the C/MRI system then uses a series of IO expansion cards to connect to pretty much anything. Updated fairly regularly the Chubb designs are now starting to show their age but are still a viable control system. Information and parts can be found at the JLC Enterprises website.

From the ever industrious MERG group in the UK comes Gordon Hopkins RPC system. Of similar vintage and technology to the Chubb system RPC relies on a series of interconnected interface boards. Having the pleasure of meeting Gordon I can only attest to his keen modelling interest and his designs reflect that. However like the Chubb system it is now getting dated, much of the work on it having been done in the late 90's.

In 2007 or so their again emerged from MERG the CBUS system conceived and developed by Mike Bolton in the UK and Gil Fuchs in California. Based on CAN bus this comparatively new system marks the beginning of the new LCB era. General purpose modules, well connected, using something akin to the producer/consumer model of operation. CBUS has a Yahoo Group as well. The boards are based on PIC controllers with CAN bus. The early boards had some issues with ground bounce and offset, but the later 12V board versions are reported to be somewhat more stable. However the practicve of sharing ground and power for the communications and operation power does detract form the stability of larger layouts. CBUS is a credit to its developers and certainly deserves a look.

OpenLCB arrived on the scene also in 2007 but began life in 2005 when I designed a DCC and accessory system that never saw the light of production. Discussions surrounding this approach stimulated Dr. David Harris and myself to explore further and through our acquaintance with Alex Shepherd in New Zealand we started devising what was at first an object oriented network which transitioned to a producer consumer network as we developed. The principal developers for OpenLCB are myself, David Harris, Bob Jacobsen (of J/MRI) and Alex Shepherd. Their is also an active Yahoo Group. Some hardware has been designed and is in use but much OpenLCB development was done on the Silicon Railway LEDuino (which includes CAN bus, DCC decoder input and rudimentary response signalling, LocoNet interface and the usual serial and USB interfaces) and other Arduino type boards. John Plocher has an Arduino model railway shield.

Don Voss proposed an RS-485 based system (as I recall) which he later moved to CAN bus in 2008 or so. Very little data has been published, but what has can be found linked on the largely outdated NMRAnet website as the S9.5 system.

There have been others, but quite honestly the details are rather vague in my mind right now and I would have to dig back into history. I should also say that I am directly involved with OpenLCB, and I have been a part of the NMRAnet community since essentially before it existed!

Tune in again for some technical discussion very soon.

Life has been busy

Life tends to deal all sorts of interesting cards to us. In the last six months I suppose the economic crisis has consumed most of us, especially those trying to hold onto our jobs! So it has been some time since I wrote anything here, but now I can remedy that neglect.

Altera/NIOS-II

Seems to have been a major focus of my work for much of the past two years. I now have four successful designs under my belt, one is in production, one is going into production now with a third to be in production in the next month or two. The fourth may never see the light of day - that will depend on the speed of another major development project I am working on.

LEDuino

My baby! This is our take on the extremely successful Arduino project. Several volume orders for special applications have consumed a huge amount of time and effort. About Octoboer 2008 we built a large batch of the revision B board which has been very successful. Finally we have had time to implement some CAN bus code for the thing and code for DCC is under way. If you want to know more, keep a watch on this page for more details.

Open source hardware

One truism that we see shouted over and over again is "you can't make money in open-source". Of course if you are reading this then it is likely you don't accept that premise. But it is true to say that for many corporations it is not possible to make money out of open-source. In my $$job we do it all the time, we use Linux, we use open-source VHDL and Verilog all the time. It reduces our development cycles, gives us a broad base of support and reduces our costs, at least up front. But as our final products required significant compliance testing and such we could never produce open-hardware the software is an integral part of the operation.

However, take things like Gumstix, Arduino, Wiring, LEDuino, DAISY MP3 player and others proves that the concept of providing a hardware design that can be duplicated is growing. No one individual or even small group might be capable of exploiting a design, but maybe others can. The Economist recently did a piece on open-source which was quite positive. One of my personal motivations for designing open-source hardware is that I am not really a programmer! I can give you really good hardware, and maybe some basic code to run on it, but be darned if I want to spend my life maintaining and enhancing it!

If course I can make money selling hardware, even when I do provide all that is needed to replicate it. How many people really have the skill and resources to produce sophisticated electronics hardware? A bare PCB sold for $20 is cheaper than the time and effort to produce something yourself. So I can make my designs, make some pocket money out of them and you can have the fun of doing things on the boards, sound like fun?

Arduino/Leduino mechanical drawing

The Arduino concept, and our own LEDuino, have been a great success. But one persistent difficulty I see is the lack of an accurate board outline drawing. At least supposedly "authorative" template I have seen had errors. So based on the Eagle files of the official Arduino Diecimila I created a layer in my EDA package that has the dimensions that as far as I can tell are accurate. This PDF file is a copy of that layer. Unfortunately I do not use Eagle but if you do, feel free to translate my drawing and I can happily post it on my site if you want.

LEDuino in the wild.

Well, the first LEDuinos are making their way into the wild. The very first shipment went to Australia. I hope the unit enjoys going back to my home country! Response so far has been very gratifying. We are working on some application examples using the LEDuino specific capabilities, more news soon.

Arduino field to get a new entry

For some time now my colleagues and I have been using Arduino ( http://arduino.cc ) style hardware based on the Atmel ATmega168 processor and a very easy to use development environment. The Arduino IDE environment is flexible enough for much rapid prototyping work, but simple enough for non-technical people to use, in fact it was originally designed for teaching design students how to build interactive projects.

The more we used the system, the more we liked it. But the more we used it the more we found we were missing some things we take for granted on our more sophisticated development platforms.So why not add some interfaces to the Arduino to make it more usable in a variety of applications?

So we sat down and figured out what we use most commonly. Thus is born the LEDuino.

• Buffered I2C bus for longer cable runs and higher bus current operation. So we added an IES5501 bidirectional driver.


• We play a lot with designs for model railway layouts. Already we use a lot of DCC, so we figured that a standard DCC decoder input, complete with basic acknowledge facility. So we added that with full galvanic isolation both ways for convenience.


• In a number of situations we use CAN Bus. Several developing or proposed model railway layout control busses use CAN, so we figured we could be compatible and give ourselves a simple development platform for that too. CAN is also used in a variety of other fields where we have some professional involvement.

So why the name LEDuino?

Well, one of our engineers develops a lot of LED based technology for architectural, visual effects and signage, he often wants to talk to serial interface devices like the TLC5940 from TI. So we added an entirely custom connector on the bottom edge of the photo, it has a serial interface that is designed to mate with some of our other products. As time goes on some of these products will be added to this range of products.

So this is it, the beginnings of a new range of Arduino inspired technology which is in fact already well proven, well used, and well liked.