Model Railway Blog 2008

I am loathe to get the baseboard out because my back is giving me trouble at the moment, which is one of the reasons there has been so little activity.

So all this excitement about the ARM prompted me to re-visit the Atmel AVR. The ATTiny12 is the 8 pin device and its internal clock runs at 1.2 MHz. If I assume the instruction cycles are on a 1:1 basis with the clock, then this compares with the 12F629. If like the PIC the ratio for the ATTiny12 is 1:4, then the PIC is better (in this respect). The ATTiny26 is a 20 pin device so it wins on pin count over the 16F628A which has 18 pins (the external clock is not multiplexed with port pins on the AVR and has its own dedicated pair). However the AVR's serial interfacing seems more complicated than the PIC. On balance for what I need to do, PIC seems like the easier choice (and the route I have gone down already). When I enter the realm of robotics, which I may do, the AVR may be more appealing.

So that is both ARM and AVR re-considered. I will not be re-considering other µcontrollers.

In the process of:

  1. Re-laying passing loop - again! The problem has been with the insulating joiners producing de-railing kinks.
  2. Finish painting track - the re-laid section and most of the pointwork needs attention.
  3. Affixing stations Platforms
  4. Affixing Goods Shed
  5. Fitting point motors - these will also switch current to the track; at present electrically dead sections can be produced.
  6. Ballasting

There seems to be a lot of excitement within MERG regarding a D.I.Y. DCC Command Station that uses an ARM µcontroller. I have had a re-look at using the ARM and I am reminded why I choose not to go down the ARM route - Surface Mount, Complexity of Programming, Price. The ARM is a very good, if not the best, µcontroller available, but not within my capabilities at present.

There is a physical and logical seperation between an LCB and the track DCC. The LCB controls the accessories and reports feedback. The DCC controls the locomotive. This seperation means that the layout can be controlled while still using DC power for the locomotive, allowing DCC to br introduced at a future date.

I have joined MERG. A side effect is that it has put a name to the project I am working on, and that is a Layout Control Bus (LCB). MERG have already produced an LCB using the CAN bus, and produces a number of kits. My LCB uses RS485 and is based on the PIC RS485 project.

The ballasting trials proved very successful. Pictures will be added in due course.

I have also subscribed to Model Rail magazine.

I have started some 'green' painting aswell.

I visited Model Rail Scotland 2008 at the SECC and thoroughly enjoyed the experience. I didn't spend much, just bought some cows, sheep and a wagon kit. Lots of great layouts to see.

Set up a small test trackbed to test some ballasting ideas. More on this to come.

The buffer-stops are fitted. I have almost completed painting the track prior to the final ballasting, only a handful of points to finish. The point motors still need to be fitted.

Not long until Model Rail Scotland 2008!


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Last updated - 5th January 2009
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