Wednesday, June 25, 2014

Arduino Loconet Shield GCA185

I have good news for those who like Arduino and Loconet. In a previous post I was talking about using a GCA50 board (from Giling Computer Applications) to use as a Loconet interface for Arduino or any other processor. That is a very good solution for those who don't master electronics and board isolation to design and build our own boards.


Giling Computer Applications is developing a new board named GCA185, and it's a perfect Loconet interface shield for Arduino. Just plug it on top of an Arduino UNO and it's ready to run. I've been able to test a prototype:

It was mounted just with the male pins, but it will have also female so you can plug more shields on top. I tried my MP3 shield, and fits perfect.

You can see it has "double loconet connectors". That means the typical RJ12 used by Digitrax, Uhlenbrock and many of the important brands, and DB9. That last is the used in GCA boards from Peter Giling and offers more reliability and extra power to feed all Loconet modules. In RJ12, Uhlenbrock tried to do something similar (in the LoconetT connector of Intellibox central stations), but for that it had to sacrifice the Railsync singal because an RJ12 has not enough pins. That's the big difference, in the DB9 connector you have all the Loconet signals plus power source.

The good point of the shield is that it has both types, and doubled (for input and output). So it can be used in any type of Loconet bus.

Arduino power source is taken also from Loconet bus, so you don't need external supply, just connect and run!!!

The new GCA185 will be available for purchase very soon, and new Arduino software will be also released taking advantage of this new shield.

Tuesday, June 10, 2014

Loconet interface for Arduino

After my last tests connecting an Arduino UNO to the loconet network, I did a better interface board using a new GCA50 board.

Just as a brief introduction:

GCA50 is an intelligent Loconet module from Peter Giling Applications. It can work both as an "outputs" or "inputs" module. Let's say it's the "brain" of a Loconet module, and connecting other boards it can drive motors, light signals, manage wheel counters or detect the presence of trains. This board contains a Microchip processor (16F874) receiving and/or sending the orders to and from Loconet. It's very easy to set up and really versatile.

But I want to create my own modules for Loconet, and be able to program them to add more intelligence and expand the possibilities to play sounds, or directly drive other Loconet modules without the need of a computer. And Arduino is a perfect platform really easy to program, and with a huge selection of compatible sensors and boards ready to "plug and program". The only missing "shield" is a Loconet board, and finally that's what I use a GCA50 board for.

I just mounted the few components in charge of converting the Loconet signal for the processor (the original Micropic), but then I connect the converted signal to the Arduino, and thanks to the MRRWA libraries for Arduino more than half of the work is done. The original board also has a current regulator taking the 12V from the Loconet and converting it to 5 volts to power the Microchip processor. But Arduino accepts a power supply of 12 volts, so all this components will neither be mounted.

Finally just the Loconet connectors, a comparator, a transistor and a few resistors are needed. I bridged the processor signals to have them available in a screw terminal block with the 12V power supply:

That's the GCA50 board turned in a simple Loconet interface and connected to an Arduino UNO with an MP3 Shield. It's able to play sounds when an output is activated or when a function key of a locomotive is pressed (each locomotive can have it's personalized sounds assigned to each function key). Also is able to "see" the locomotive that stopped in front of the station and play the correct announcement.

 Now the final step would be to develop this exact interface in an "Arduino shield" type board, and plug it to the arduino like normal shield boards.

Friday, June 6, 2014

Tomix 92214 ED75 Decoder install

This is the Tomix 92214 model, including an ED75 locomotive and two Koki freight platforms:

"The ED75-1000 subclass were built from 1968 for use on express freight services. 25 locomotives were built between 1968 and 1970, followed by a second batch of 14 locomotives built from 1973 to 1976, bringing the total to 39.  JR Freight started a programme of life-extension refurbishment of its Class ED75-1000 fleet from 1993, and refurbished locomotives were initially repainted in a new livery with the bottom half of the body sides finished in ivory. The livery applied to refurbished locomotives was subsequently simplified to just adding a white stripe along the bottom of the body sides." - Wikipedia source

Disassemble is quite easy, just pulling the hull up. The two gray plastic pieces are also clipped. Then you have to unclip the bottom black piece between the boogies, and the two lead pieces will separate releasing both boogies and the led boards.

I spent a lot of time thinking where to fit the decoder, and finally I found the only possibility inside the plastic piece which clips the lead big blocks.

Anyway seems difficult, because the decoder needs more room, and that's one of the smallest in the market (Digitrax DZ125). The big metallic blocks also act as current conductors and seems difficult to isolate the engine and lights. And besides seems there is no place for wires!!!

Then my idea was to use an even smaller decoder, the brand new model from digitrax. It fits perfectly and there is no need to sand anything.

But once it was mounted, fitted and soldered, the decoder was faulty and giving always 17V to the engine, so I'll skip all this part of the installation... :((

Well, that was my plan, as there is no room for wires I'll use very thin brass strips. It's a solution that I never used before, and I think it will be my standard way of digitalize from now on. All the strips must finish under the locomotive in the small place where the decoder will be fitted. Soldering two short strips to the engine nose clips, they act also isolating them.

The second challenge is to replace the white leds and add a rear red light. The original model only comes with front light, but no rear one.

As there is only space for one led, changed them for a bicolor SMD led (red / sunny white), soldering it to a piece of the same brass strip and with a 1KOhm resistor:

In the middle of the locomotive two brass strips will feed current for leds, and very thin wires will connect the feeding brass strips to the led strip. Led strip is bended and fixed with glue to the existing led boards after removing the old led and resistor.

And that's the model ready to close and test. Just one update, the little piece of double sided tape had to be removed also, and the led boards installed in an inverted way, so the led is in the bottom of the board and not in the top:

Locomotive working!!!!!

I heard Kato model is much easier to convert to DCC, this one really became a challenge and is the most difficult one I ever did. But the behavior and engine softness is amazing, despite I haven't seen Kato model.

BluRay "Decoder" install

I suppose many of you also like Japanese films and Anime. Manga and Anime is really part of the Japanese culture. That's why you can see many Japanese trains decorated with anime motifs, like the "Mangattan Linner" or the newer Evangelion train. In my last trip to Japan I rode the "Tomas the tank" train.

But that wasn't to talk about "Manga" trains, it was about watching Japanese DVD and Blurays. Until now I was able to see any Japanese DVD because despite there is a region protection, Japanese and Europe shared the same. But recently I bought a Japanese BlueRay, and realized they changed the region protection zones established for DVDs, and it's not possible to see a Japanese Bluray in a non-japanese player.

Solution: hack the Bluray player installing a chip inside, what doesn't differ too much from installing a decoder in an analog locomotive!! I found RattleByte sells this kind of mod-chips for my Sony BDP-S100 player (a really cheap one). It comes the chip, thin wire, double sided tape and the instruction manual with a clear photo indicating the soldering points:

In my model it needs to solder only 6 wires:

Just two of them are complicated, one because it has to be soldered to a really tinny resistor, and the other because the access to the soldering point is not easy and the main board must be unattached.

The other 4 wires are soldered to existing tin pads.

And now my Bluray player can play DVD and Bluray from any region without problems. I hope you enjoyed it!!!