Automatic Smoke Control

Nicely done John!  What's the source of the little prototyping board you used?

You might reduce the size by using an AC optocoupler.  But could it be done with a transistor or triac instead?

The board I use is just some ancient S-100 computer prototyping boards.  They're about 5x10, I cut them in little pieces for projects.

I don't know that I'd get it any smaller, given that I needed at least an amp of current capability.  Also, this stuff was all in my parts bins, so it was a no-cost outlay.   I needed total isolation, so there has to be an opto-coupler in there somewhere.

I'm sure there are other ways to do this, but this solved my problem and I could make it small enough to fit.

I did draw a diagram, if you do what I said and view the image, it'll come up full resolution so you can read it. 

The only "mystery" parts are the relay and opto-coupler, and those part numbers are on the schematic.  The Schottky diodes were just some I had from years ago, they're rated at 50 volts, for a smaller footprint, you can also find Schottky bridge rectifiers in small packages.  All resistors are 1/4w and all the caps are 50V rating.

Very nicely done John, I learned a lot from you over the past year.

Thanks, Alex

Thanks guys, I figured that maybe someone else might have a similar issue. 

I'm currently fooling around with the Arduino programmable controllers, so I might be doing some stuff with those soon.  Bare chips can be had for less than $5, and you can have pretty much any logic you require.

Thanks for posting John. I'm still learning and have a far way to go but everyone of your posts makes things just a little bit clearer in my head. I don't have an electronics spare parts drawer. I have been writing down the parts that you and others mention.  I'm ready to take the plunge and order a crazy mix of things and start to experiment a bit. This is something I would not have considered just a few months ago. 

The Arduino is a lot of fun.  I developed a TMCC/DCS automated control & signaling system with the Arduino, and use it to interface with a USS-style control panel built with JMRI.

After you do a couple of these, you'll be an old hand.  I have to admit, having a ton of parts available does make it easier.  You just have to come up with something you need, then see if you can build something to solve the problem.

Are you actually decoding the TMCC data stream?  If so, I'd be interested in that.  I'm thinking of decoding the data and building a little trigger module to fire off sounds in response to the whistle, bell, and perhaps other unused keypad combinations.  Since the Arduino is programmed in C, it's old hat, I've programmed in C since the 70's.   I just got the little Uno board and a couple of the Mini boards today, fired the Uno board right up and ran a program right out of the box.  Made a few mods and had a LED tree running in about 15 minutes.  Clearly, they went out of their way to make this easy.  The mini boards look small enough to bury in things.

I had looked at the PIC processor, but their development environment is really complex and buggy!  I bought a little development board, and they could never tell me why it wouldn't connect.  I even exchanged it, still wouldn't connect.  I decided to look elsewhere. 

I am sending commands to the Legacy base rather than reading them, but it is easy to read the output from the base's serial port.  (If you're using Legacy you'll want a MAX232/equivalent, or use the software serial library with a limiting circuit).

I wound up using a Mega, in part for the program space, but mostly for the extra serial ports - I talk to the Legacy base, the TIU, two RFID readers, and two connections to the PC all at once

If you're interested in wireless applications take a look at the Jeenode - it's a compact Arduino with built in 915 Mhz networking.  If you want wireless TMCC-controlled remote accessories without the ERR route, it would be easy to have one Jeenode read the echoed serial commands from the Legacy base, and then send commands to other Jeenodes around the layout or in rolling stock.

just a question you gurus

could this also be used on a dcs System to control MTH  animated cars

I'm actually interested in reading the serial data from the R2LC that goes to the RailSounds module.  I have no doubt electrically, but decoding the serial stream is my real question.  I've never seen it documented.

I don't think so - while it is possible, with difficulty, to transmit pre-specified commands to the TIU, MTH makes it impossible for users to read the commands being issued from the TIU.

If you have TMCC it is straightforward to use Electric Railroad Mini Commanders to control animated cars - if configured as an ENG, you can control them with the DCS remote through the TMCC base.

I've automated a number of operating cars using the ERR Mini Commanders.  If you don't have TMCC, pick up a used command base and connect it to your DCS system, PRESTO you have TMCC.

I'm actually interested in reading the serial data from the R2LC that goes to the RailSounds module.  I have no doubt electrically, but decoding the serial stream is my real question.  I've never seen it documented.

It's the same bits as in the the last byte of the 3 byte data stream. It repeats every 8.3 msec. When there's no command the bits are all zeros.

Are you talking about the documented TMCC communications from the command base to the locomotive?  Is it really as simple as reading that at 9600 baud as a single byte?  How about format, start bits, stop bits, etc.?

I'm referring to this table in Lionel 71-2911-250 in reference to the command values.

Sorry, looks like it's 9 bits- 1 start and 8 data. The byte is about 2.6 msec long whatever that works out to in baud rate and repeats every 8.3 msec, when there's no command the byte is a hex 01.

I'll have to dust off my serial data analyzer and see if I can read this.  I wish I had a storage 'scope to capture it, but I just have an old-school analog 'scope.  That sounds like an odd baud rate, looks like I'll have to check this out.

That sounds almost too simple, I was figuring on something more complicated.

I'll bet this would be a piece of cake to read with the Arduino processor...

John,

Start reading from page 36 on in this document - it may help

http://www.lionel.com/media/se...ents/71-2911-250.pdf

Best,

Dave

I'm talking about the output from pin 24 of the R2LC. It's simply just the 3rd byte of the 3 byte string the R2LC receives. Repeats every 8.3 msec which is synced to the 60 Hz AC. I looked at my notes (from 13 years ago) a little more closely and it now appears that it is a zero start bit, the 7 data bits as per the Lionel table and then a zero stop bit. Except when there is no command being received then it's a zero start, 7 zeros for data, and a 1 stop.

That's where the table I posted previously was from.

I realize you were talking about the RS audio serial data on pin 24.  I am a bit surprised that they have vary the stop bit, that's pretty odd for any serial protocol.  I'm going to actually look at the data and see what I find, I'm sure I can decode it.

I fixed the original post, the graphics were missing.

I've since done an updated version of this idea, here's the latest schematic.  This incorporates several ideas that were presented in a couple of threads for improvements.  I used the suggested AC opto, and also added a FET with a delay circuit to eliminate low speed chatter of the relay.  This circuit is rock-solid and I use it for smoke control, cab lights, and Rule 17 lighting.

Oh sure, I happen to have an MTH 0-4-0 on the way and when I find this thread it's all about that TMCC stuff yet again...your killin me John!

...BTW, hows that lil sucker run B4 TMCC...I can wait and find out but maybe you'll throw me a bone here{I just liked the looks of it and I didn't have a small steam switcher}.

Bob

I use my MTH 0-4-0 B&O switcher everyday on the layout....it will pull 15 or 16 RMT cars around my 072 layout without a problem...(all level track of course) it is a joy to switch cars with in my small yard. I have plenty of PS2 switchers both steam and diesel and I do run DCS...but this little loco is a lot of fun to run with the handle on the transformer...and heres the best part ! NO TRACTION TIRES !!!

I've pulled 19 ore RMT ore cars with it, but it had to drop off about five of them on the 2% grade, just didn't have the traction.  It runs great with TMCC, I only wish I had enough space for sound.

Very nice!   hey, I thought about using a railcar like a hopper to install a PS-2 board in it, then run the wires with harness into the dockside switcher to operate the motor and smoke unit.  But, I wonder if MTH has any programs for the small wheel revolutions that this unit has.  I know my blue comet has small wheels, but Diameter is unknown comparison to both units.   

with that said, anybody do this before with using a railcar with the PS2 electronics?

Chris

You can build a custom tach tape to try to match the speeds.  The worst that can happen is the scale MPH numbers are not accurate, no big deal.  Since you'd need fewer stripes to adjust the speed I would think, there shouldn't be an issue of the tape being incompatible with the tach reader.

I have never seen a car used, but MANY PS/2 steamers use the tender, so it's clearly not a foreign concept.  The car would serve the same purpose, add a tether and you'd be all set.  The PS/2 upgrade kit has the tether and everything you'd need to do this.