Automatic Control Of Legacy Subway Set

Matt, it would be possible to program automated operation by sending commands to the Legacy base through the serial port.

However, you would probably need to have some hardware to detect the train at each stop. This might be doable with the LCS sensor track, but I don't know anything about that system.

However, it would not possible to detect the train with an isolated 3rd rail or an infrared sensor, have an Arduino read those inputs, and then use the Arduino to send the appropriate command to the Legacy base. I have automated my entire layout with such a system. The most challenging part would be interfacing your train detection to the Arduino, but it is not too difficult if you like tinkering with electronics. The Arduino is essentially programmed in C++.

@Professor Chaos posted:

Matt, it would be possible to program automated operation by sending commands to the Legacy base through the serial port.

However, you would probably need to have some hardware to detect the train at each stop. This might be doable with the LCS sensor track, but I don't know anything about that system.

However, it would not possible to detect the train with an isolated 3rd rail or an infrared sensor, have an Arduino read those inputs, and then use the Arduino to send the appropriate command to the Legacy base. I have automated my entire layout with such a system. The most challenging part would be interfacing your train detection to the Arduino, but it is not too difficult if you like tinkering with electronics. The Arduino is essentially programmed in C++.

Thanks for the info. "However, it would not possible to detect the train with an isolated 3rd rail or an infrared sensor, have an Arduino read those inputs, and then use the Arduino to send the appropriate command to the Legacy base. I have automated my entire layout with such a system." Did you mean to say, it is  possible to use an Arduino? Also, I forgot to mention, I do have a raspberry Pi, could the same thing be accomplished?

Hi Matt - oops, editing error;  it would be possible"!

I've not worked with a Pi, but I think you could do the same thing as long as keep the Pi's 3.3v supply in mind when interfacing to the command base (RS-232) and the track occupancy sensor of your choice.

As an example, here is a track occupancy circuit I use to get a clean 5v logic signal from an isolated third rail on the track. You could probably use a simpler circuit if you wanted to clean up the signal in software, or use an infrared detector.

@Professor Chaos posted:

Hi Matt - oops, editing error;  it would be possible"!

I've not worked with a Pi, but I think you could do the same thing as long as keep the Pi's 3.3v supply in mind when interfacing to the command base (RS-232) and the track occupancy sensor of your choice.

As an example, here is a track occupancy circuit I use to get a clean 5v logic signal from an isolated third rail on the track. You could probably use a simpler circuit if you wanted to clean up the signal in software, or use an infrared detector.

Cool! I'll have to get the materials together and get to work. Writing the program may be a challenge though. 

You might find this simple Arduino code helpful. It shows how to transmit Legacy fixed 3-word (9-byte) commands, based on the description on pp. 10-11 of the Legacy protocol specification.  This example uses subsystem 2 for triggering dialogs; you would use subsystem 4 for subway stops as shown on pp. 15-16. 

For starting and stopping the train you would use the 3-byte engine or train commands as described in pp. 8-9 of the protocol.

@Professor Chaos posted:

You might find this simple Arduino code helpful. It shows how to transmit Legacy fixed 3-word (9-byte) commands, based on the description on pp. 10-11 of the Legacy protocol specification.  This example uses subsystem 2 for triggering dialogs; you would use subsystem 4 for subway stops as shown on pp. 15-16. 

For starting and stopping the train you would use the 3-byte engine or train commands as described in pp. 8-9 of the protocol.

Cool stuff. Thanks! Was that document made by you or someone else? Also, was it in C++ or another language? 

It's a program I wrote for the Arduino. It's essentially C++, but with the Arduino extensions. 

@Professor Chaos posted:

It's a program I wrote for the Arduino. It's essentially C++, but with the Arduino extensions. 

Ah cool.