Phase II of my miniDCC project

Here are some pictures of the current incarnation of my miniDCC project. I moved everything to a project box, changed the keyboard and added binding
posts for the track connections. Still needs some finishing work to clean up the openings and labeling. I think I'll sand and paint it to minimize the dremel scuff marks. Any recommendation on paint that will work with ABS plastic? How about inexpensive but worthy air-brushes?
http://i55.photobucket.com/albums/g143/afremont/DSC01227.jpg
http://i55.photobucket.com/albums/g143/afremont/DSC01228.jpg
http://i55.photobucket.com/albums/g143/afremont/DSC01229.jpg
http://i55.photobucket.com/albums/g143/afremont/DSC01230.jpg
http://i55.photobucket.com/albums/g143/afremont/DSC01231.jpg
http://i55.photobucket.com/albums/g143/afremont/DSC01232.jpg
http://i55.photobucket.com/albums/g143/afremont/DSC01233.jpg
http://i55.photobucket.com/albums/g143/afremont/DSC01234.jpg
http://i55.photobucket.com/albums/g143/afremont/DSC01236.jpg
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On Sat, 12 Jan 2008 15:27:21 -0600, I said, "Pick a card, any card"

Pictures of your project are nice but technical details would be just as interesting to some. -- Ray
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Ray Haddad wrote:

Right now there's not much to say that isn't covered here: http://home.cogeco.ca/~rpaisley4/MyDCC.html
The small board on the bottom is the PIC board with connectors for the keypad and LCD cables. The larger circuit board is the "safety" board that keeps an eye out for short circuits and a missing DCC signal from the PIC. It turns off track power under these conditions.
It's just my rendition without the walkaround controller. Since I'm using a wall-wart, I put everything inside the project box instead of having two seperate modules. I think I'm going to replace the 12V power supply with a 16V like the Bachmann EZ-Command uses for a little more oomph.
The source code for the PIC firmware doesn't seem to be available, so I'd have to completely rewrite the code to make any customizations. I'm seriously considering replacing the PIC with an ARM header board (orders of magnitude more powerful than the PIC) so I can do it all in C and make the user interface a little more friendly.
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On Sun, 13 Jan 2008 09:48:15 -0600, I said, "Pick a card, any card"

Sorry, mate. For some reason I though this was a new design of your own. I am still interested in your progress so do press on!
Doing something yourself is always rewarding. -- Ray
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Ray Haddad wrote:

From this point forward, it will pretty much be my own design. Especially after I replace the PIC with a "real" processor. ;-) That will make a friendlier user interface a piece of cake. The rest of the circuitry is pretty much required for any DCC system. In fact I need to add an ack detector to make it more complete.

It's usually cheaper too. :-)
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On Mon, 14 Jan 2008 11:04:10 -0600, I said, "Pick a card, any card"

The PIC is a very real processor that uses Harvard Architecture to reduce instructions. In surfing the web, I discovered several folk who had designed interfaces to PCs via the parallel port and software in the PC. Looked to me like even an old 386 would make it work. You could always move on to a PC which sort of makes it nothing more than a screen game.

Particularly the decoders for a large herd of engines. -- Ray
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Ray Haddad wrote:

I was just kidding. I've done dozens of PIC projects, I'm just tired of writing miles of PIC assembler to get something done. The PIC is a great processor IMO. The ARM processors offer incredible bang for the buck. I'd say a current ARM7TDMI processor would run rings around an old 386. Easily running at >60MHz and executing nearly every instruction in one clock tick, it really honks. :-)

I intend to add some sort of computer connectable interface. Maybe TCP/IP based, but more likely just a serial interface of some sort.

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On Mon, 14 Jan 2008 15:54:35 -0600, I said, "Pick a card, any card"

I'd be looking at 802.11g myself. I mean, why not? There are tons of wireless routers out there just that can be secured just waiting to be bought for $5.00 or under at thrift stores. Computer people don't suffer obsolescence very well. They go for the best and fastest leaving really good stuff in the dumpster.
There's a really inexpensive ethernet design tool out there. Check this out: http://wiznet.co.kr/main.php
For less than $50.00 you can have both sides communicating to the router or for $24.00 you can have the PC doing the hard work and the receiver (at the train control room) attached via the router. I'm sure you can get the idea of what I mean. -- Ray
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On 1/14/2008 1:54 PM Anthony Fremont spake thus:

Macros? That can get you a lot closer to C and more compact code. How's the PIC assembler when it comes to timesavers like those?
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On Mon, 14 Jan 2008 15:30:13 -0800, I said, "Pick a card, any card"

PIC assembler supports macros. There are no shortage of C compilers out there for PIC devices. The best being this one: http://www.ccsinfo.com
They update as required, even multiple times in a single day if a bug is serious enough. It has the best IDE around supporting all the programmers out there. It has the fastest compile time and the most compact code. It allows in line assembler or an assemble include file for those routines that you just love to bits. -- Ray
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Very nice.
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On 1/12/2008 1:27 PM Anthony Fremont spake thus:

Dunno about inexpensive, but my Paasche VL double-action has performed flawlessly for lo these many years. I recommend it.
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*snip: photo URLS*
Inexpensive would probably be a can of spray paint. You can get stuff formulated to stick to plastic, or at least a primer for plastics that a paint will stick to.
I've got the Testers cheap air brush that Walmart sells. It's ok, as long as you think of it as a can of spray paint that you can change colors with. It's been used about 20-30 times, and seems to be holding up pretty well.
Puckdropper
--
Marching to the beat of a different drum is great... unless you're in
marching band.
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