TMCC RailSounds Command Format

I may be wrong in my thinking, but if you have 8 data bits, one start bit and one stop bit, that would give you 300 bytes per second after ignoring the start & stop bits. Which equates to a standard baud rate of 2400bps. Or am I thinking too simplistically here?

Sounds like a good project.  As far as the amplitude of the signal, that is the signal that comes right out of the R2LC, it just goes through a trace on the ERR Cruise Commander to the RS4 board set.

 

As far as the commands, have you looked at the The complete guide to command control - Lionel, it details all the commands.  The page below is where I got the command structure from, and as you can see, it lines up exactly with the three commands I sent and what I saw.  The Alt+0 button, for instance, would send the ALT1 command from the table below and then the numeric command for 0, i.e. 00010000 with a low start bit and a high stop bit.  Note that a leading zero is not in the table, and also the bits come out LSB first on the serial link.

 

The screenshots are from an ATTEN ADC1102CAL digital 'scope, a recent acquisition for doing projects like this.  I got tired of trying to see this stuff on an analog 'scope.

 

 

I thought the coses were published someware. Be advised that the Legacy R4LC board outputs 9 bits in a Legacy invironment. Either board also has several outputs that are of an on/off nature for such things as the Smoke generator and lights and a pulse Length modulated (PLM) signal to control the motor speed and direction. The signal on the dataline for the coupler only serves to trigger the coupler sounds in the sound system, the couplers are controlled by one of the on/off outputs for all but the tender coupler.

 

Al

 

 

First off, I'm not looking at Legacy, since that is a patent issue, and I couldn't sell or distribute anything based on decoding the Legacy.  I could decode Legacy for my private use, and at some point I might consider it.

 

I realize that this is not the actual control outputs, but if I key on the sound command, I get the same effect for detecting remote button presses.  As far as stuff like the PWM signal for speed, I'm just looking at the data going to the RailSounds board to trigger sounds, I'm not worried about decoding PWM streams, though that is pretty trivial if I were to consider that in the future.

 

The purpose of this project is to intercept the commands to the RailSounds board and trigger events based on the commands issued to the command content.

 

What are coses?

Sorry man, didn't mean to srep on toes. One missed finger press and I get called to task. The S and D are next to each other on the keyboard. I will just have to bone up on my mindreader skills and proof reading ability.

 

Never finished cowledge so my skills r not goot.

 

Al

I didn't get it, sorry Al.   I was wondering if it was a new engineering term.  I'm not sure where you were stepping on toes, if I conveyed that message, it was in error.

 

As far as the codes, I posted the page from the manual where they're listed.  I'm interested in the exact bit rate, it appears to be about 3000 BPS, but that seems an odd choice.  I think the actual command codes make sense, I was able to see how they correlate with the stuff I was capturing.  Interesting that the output to the RailSounds board is only the actual command byte, and not the first byte of the format.

 

As I stated in a post on another similar thread I've done many projects decoding the serial data. For example Atlas wanted to add working ditch lights to their diesels. Ditch lights operate with the horn so I developed an 8 pin PIC that decodes the serial data from pin 24 of the R2LC to operate the ditch lights, A long time ago in a galaxy far away I did a circuit for TAS where we expanded the CAB1 keypad. By entering a special sequence on the keypad we added a bunch of extra features. For example KP (keypad) 1 and 2 controlled smoke volume (1 increase, 2 decrease), KP 4 toggled classification lights on/off, KP 5 toggled number board lights, KP 5 toggled firebox glow, etc. I still have several engines running with that board.

So what's your question?

I just dug out my software from 12 years ago for one of those projects. The serial data stream codes are the same as in the Lionel chart as shown above.

These are examples of the codes in hex:

1C = horn

1D = bell

01 = direction

07 = brake

04 = boost

09 = aux1

0D = aux2

11-19 = Keypad 1=9

etc

Hope this helps

What I find interesting is there is nothing on that list to trigger engine sounds. Since track voltage is always constant, how does the railsounds board know when to change engine RPM sounds?

It might monitor the throttle commands.

As I stated, my primary question is the bit rate of the data?  It looks from what I captured that it's 3000 BPS, which seems to be an odd rate.  Is that what you saw?


Interesting question, I'm not sure I know the answer yet.

I see 320 usec per bit. Whatever that works out as. Small PICs don't have a UART built in to set up to receive at some specific Baud rate so I had to read the data bit by bit.

Well, that's what I'm seeing too, I found it odd that it was running at 3000 BPS, so I was looking for confirmation that I wasn't screwing up.

 

I was also somewhat surprised that the amplitude of the signal was only 2.5V P-P, is that also what you see?  I'm sure I can deal with that, just wondering.

 

I'm using the Arduino, so I have a UART, but I may not be able to use it.