Digitization of a BB 27000 Mehano

Now that it is pretty clear that Os.Kar will very unfortunately never produce the BB 27000 and BB 37000 engines, I decided to get the Mehano models. They are not as nice and detailed as what Os.Kar would have done, but it is something anyway.

I focus in this post on the digitization of the engine. I will talk at this end about what I have found to further detailed the Mehano models with several kits.

Quick run in analog

In this video, I did a quick run in DC to make sure everything was going smoothly:

Disassembly

I followed the instructions to take the engine apart:

1. Remove the 4 buffers - I'm missing one actually. Just have to pull carefully
2. Remove the 2 couplers
3. Remove the 2 "chasse-pierres"
4. Remove 2 small parts in the center of the engine
5. Spread the sides of the body to separate it from the chassis

One more quick run on the test bench:

Decoder installation

I purchased the sound decoder from Train Modelisme: https://www.train-modelisme.com/mag.php?goto=bout.php&id=14652&famille=Digital&cat=%20%20&pro=o&cat2=$cat

It is the ESU 58410 LokSound 5 already programmed by Train Modelisme with the sounds from Bastiani.

The decoder is very easy to install: just take out the little circuit board and insert the new one. The direction is very important and somewhat explained on the Mehano instructions: the wires have to come out opposite of the screw that is near the DCC plug - or just see above.

It works!

The functions of this decoder are provided here: https://www.train-modelisme.com/data/Loksound%2027000.JPG

Sound box

As mentioned on the Train Modelisme webpage, the machine can use a sound box to increase the quality and power of the speaker. I used the 23mm box from ESU 50341, but the 20mm might have actually been a better fit:

And it is indeed much better:

Putting everything back together

There is a specific place for the sound box and the decoder goes under the chassis. I used normal tape to stick everything together, but I don't think it is the best option. I have to do a little research on this.

And the final video:

Improving details

The next step and next post will be about improving the details. There are multiple options:

• Lighting kit from Miniatures Passion: https://www.miniaturespassion.shop/index.php?id_product=162&rewrite=kit-d-eclairage-a-leds-pour-jacquemin-4-phares-roco&controller=product
• Coupler kit SMD017 from SMD Productions: http://www.smd-productions.fr/smd017.html
• Footboard kit SMD018 from SMD Productions: http://www.smd-productions.fr/smd018.html
• Footboard and bogies kit HM 44113 from Haxo Modele: http://www.haxomodele.fr/accueil/mobile/?page=Pi%E8ces%20d%E9tach%E9es%20transkit%201-87
• Cabin lighting kit from Miniatures Passion: https://www.miniaturespassion.shop/index.php?id_product=77&rewrite=eclairages-led-2ma-pour-cabine-de-locomotive-lot-de-10&controller=product

There are two articles in Loco Revue nº 710 from September 2006 that describes the kits from SMD Productions and from Haxo Modele. The second article talks about putting better pantographs; I've been told from a reliable source that I should use those from the Jouef BB 36000.

And finally some links:

• http://forum.e-train.fr/viewtopic.php?f=65&t=3131&hilit=mehano+27000
• http://forum.e-train.fr/viewtopic.php?f=2&t=4015&hilit=mehano+27000
• http://krmelj.net/index.asp?p=zel_pro&sk=H0&gr=Spare%20parts

Ampoule LF RFID Tags

So, I was a bit underwhelmed with the previous tests with the ampoule HF tags and the Velleman readers. I, somehow, ended up on this website: https://www.locoduino.org/ and found many interesting Arduino projects for model railroad:

• "Réalisation d’un wagon de mesure" - https://www.locoduino.org/spip.php?article259
• "Annonces en gare avec RFID" - https://www.locoduino.org/spip.php?article248
• "Affichage de gare" - https://www.locoduino.org/spip.php?article205
• "Connaitre les numéros de trains avec un capteur RFID" - https://www.locoduino.org/spip.php?article41

I am focusing on this last project, but the other two, and probably more on the website, are very comprising. The article mentions that the reader can be purchased at Sparkfun. After a bit of research, I ordered the following from that website:

• SparkFun RFID USB Reader - SEN-09963 - https://www.sparkfun.com/products/9963
• SparkFun RFID Qwiic Kit - KIT-15209 - https://www.sparkfun.com/products/15209
• RFID Reader ID-20LA (125 kHz) - SEN-11828 - https://www.sparkfun.com/products/11828
• RFID Glass Capsule (125kHz) - SEN-09416 - https://www.sparkfun.com/products/9416

Then, I realized that the SparkFun RFID Qwiic Kit needs a Redboard, which I bought at MicroCenter. But I actually needed to get a RedBoard Qwiic:

• SparkFun RedBoard - Programmed with Arduino - DEV-13975 - https://www.sparkfun.com/products/13975
• SparkFun RedBoard Qwiic - DEV-15123 - https://www.sparkfun.com/products/15123

The Qwiic connector is needed to connect the board to the RFID reader. A Sparkfun RedBoard is in fact just another Arduino Uno, so I'll use the one from MicroCenter for some other Arduino projects.

In summary, here are all the components I got:

RFID Reader ID-12LA (125 kHz)	RFID Reader ID-20LA (125 kHz)
SparkFun RFID USB Reader	SparkFun RFID Qwiic Reader
SparkFun RedBoard Programmed with Arduino	SparkFun RedBoard Qwiic

SparkFun RFID Starter Kit

Considering that I'm waiting for my SparkFun RedBoard Qwiic, I have to start with the USB Reader that does not need any board.  This is well explained in this documentation: https://learn.sparkfun.com/tutorials/sparkfun-rfid-starter-kit-hookup-guide

With the USB Reader, I just have to plug it directly to the computer and launch Arduino IDE. The port might need to be adjusted, but the serial monitor displays the necessary information. This was super easy.

One detail is that by default the module buzzes every time the reader reads a tag. I wanted to remove the buzzing as it is quite loud. As per the documentation, I was supposed to remove the soldering at the jumper, but I was not successful in doing that. I decided to desolder the buzzer itself.

RFID Reader ID-12LA

RFID Reader ID-20LA

Reading ranges

Here's a summary of the ranges for the ampoule RFID tags 850-0073-420-13F 20x4mm at 125kHz:

Reader	Reading range
ID-12LA	14 mm
ID-20LA	16 mm

Ampoule RFID tags

The reading ranges are slightly better than the HF 13.56 MHz tags from RFID Inc., but the real advantage on these  LF 125 kHz tags is the size. Judge by yourself, but obviously, the LF tag is much much smaller, which means that it will be easier to fit into rolling models. The disadvantage is the cost: an HF tag is about $1.86 a piece, whereas a LF tag is $4.95.

Next steps

There are a couple of things to follow-up on:


1. Once I get the SparkFun RedBoard Qwiic, I will follow the documentation: https://learn.sparkfun.com/tutorials/sparkfun-qwiic-rfid-idxxla-hookup-guide. I expect it to be like an Arduino Uno, so my Python code should work in a very similar way

2. While reading at the ID-xxLA reader documentation, I decided to visit the manufacturer's website: http://id-innovations.com/httpdocs/Modules(non%20write).htm. Under my readers, there is the following note:

Please kindly notice that Sparkfun USB adapter board/start kit/Qwiic kit gives less than 50% of the normal read range. If the reading range is critical for your application, please try DM-12LA Demo Kit

I've reached out to the company to see where I could purchase the DM-12LA Demo Kit to have allegedly a 50% longer reading range:

• Website: http://id-innovations.com/httpdocs/demonstration%20kits.html
• Documentation: http://id-innovations.com/httpdocs/DM-12LA%20kit%20packing%20list.pdf 

DM-12LA Demo Kit

Stay tuned!

Ampoule HF RFID Tags

As mentioned in my first post about RFID, I ordered ampoule tags from RFID Inc.: https://www.rfidinc.com/hf-13-56-mhz-rfid-glass-ampoule-tags. After a couple of emails with the people at RFID Inc, the order has been adjusted to the following items:

• Model HF-1575-312 Glass Ampoule RFID Tag, 12x3mm, ISO 15693 SLI memory chip SKU: 850-0073-312-04
• Model HF-1575-420-13F Glass Ampoule RFID Tag, 20x4mm, ISO 15693 NFC memory chip SKU: 850-0073-420-13F

Those ampoule tags are HF, so for a frequency of 13.56 MHz. The people at RFID Inc warmed me that those tags might not be able to work for my use case. So I decided to test the range of those tags with the two RFID readers from Velleman: VMA405 and VMA211.

Velleman VMA405 & Ampoule 850-0073-312-04

Well, this just does not work at all. I'm not clear as to why. I anticipated that the range will be minimal since it is the smaller tag, but even when putting the tag on the reader, I get nothing.

So, not successful at all!

Velleman VMA405 & Ampoule 850-0073-420-13F

I get a good read on those larger tags and it is quite consistent. It seems that it works best when holding vertically:

As we can see here, it works quite well:

Velleman VMA211 & Ampoule 850-0073-420-13F

So let's try again now with the VMA211 reader. The reason that I would need this one is that the antenna of the reader is a flat piece of circuit board that can easily be positioned under the tracks.
Note that by default, the VMA211 is configured to use the onboard antenna and not the off-board one. This is well explained in the documentation. From the same document, there are a few things to install: https://www.velleman.eu/support/downloads/?code=VMA211

• VMA211 Example
• SPI
• PN532 SPI

The VMA211 is super easy to connect as it stacks directly onto the Arduino UNO.

Conclusion & Next steps

Here's a summary of the ranges for the ampoule RFID tags 850-0073-420-13F 20x4mm at 13.56MHz:

Reader	Reading range
VMA405	10 mm
VMA211	15 mm