What is a LaunchPad?  I'm not talking about some cheesy "action" accessory made by Lionel in the sixties.  What I am talking about is a microcontroller development board from Texas Instruments that has the potential for scores of uses on a model railroad.  The Texas Instruments MSP430 Launch Pad (MSP-EXP430G)

A microcontroller is, essentially, a computer system on a single chip, including some hardware that ordinarily would be external to and would have to be connected to a conventional microcomputer.  Today's microcontrollers are essentially as fast or faster than the '486 generation of microcomputers. Whether you know it or not microcontrollers are embedded into many of the systems model railroaders use today.  They are in each DCC decoder, in the command station and handhelds.  Accessory decoders and the products from Tam Valley Depot are built around them as well.

What's unique about the Launch Pad is that you can buy one from TI for $4.30 - that's not a misprint.  For less than $5 you get a development board, two target microcontrollers and some accessories.  This makes the TI board much cheaper that similar products from the competing microcontroller lines and it's cheap enough that the Launch Pad can be incorporated right into your projects.

What can you do with one?  Among other things, microcontrollers can directly light LEDs therefore they can be used for all manner of things like crossing flashers, traffic light sequencers and signaling systems.  In addition to illuminating the lights, the microcontroller can incorporate the logic to determine which lights to turn on.  You can program one to sequence the lights inside of a building or factory to imply activity inside. The logic for a bi-directional, three color signaling system is created using a surprisingly few lines of code.  In addition, with a few external components the same microcontroller can also detect the presence of the trains.

Turnout control using either stall motor (Tortoise) machines or servos is possible.  There are accessory boards available for the Launch Pad that enable it to store and playback sounds, opening the possibility to add sound sequences to your scenes.  Because the Launch Pad has a USB port on board that is accessible from the target microcontroller, the potential exists for tying many Launch Pads together into a network so that they can be controlled from a central location, or tied into a system like JMRI.

The microcontroller has to be programmed to function. The programming language (C or assembler) and environment is available free from TI.  If you cannot program, don't despair  I'll address that shortly.  Because these can be programmed, you can customize one for whatever functions you need.  Need B&O four-color signalling with all six marker indications (about 37 different signal aspects including flashing)?  You can program that complex signal system into one of these - and in many cases you can do it without additional hardware.

So what if you cannot program?  Well you could learn.  I hadn't programmed anything in almost 25 years before I took to programming the Launch Pad; and I had a couple of projects up and running in two days - including the time it took me to learn the "C" programming language.  I will be trying to cajole some of my buddies at Model Rail Radio to create some tutorials on how to learn and program in C.

For those of you who don't want to program, but want to give this technology a try anyway, I'll be putting up the programs created by me and others. so that we can share and use the code created by all.  You'll be able to grab the code, compile it using a simple process and load into your own LaunchPad.  In this way I hope to foster a community where we can share applications for the TI Lanuch Pad  for model railroad use.

This is not intended to be a blog just for geeks; although I hope that a lot of geeks will be making contributions. But I want to keep this blog simple and understandable for the non-technical, because our common objective is more enjoyment form model railroading.


  1. Great applications! Looking forward to trying them. I'm thinking about a sequential LED driver to power 4 surface mount LEDs to simulate the figure-8 pattern of a mars light in O scale.

    Basic Question: What is the advantage to using LaunchPads vs the microprocessor chip alone in applications? Once you program the chip, you can use it in a standalone circuit with a power supply, correct?

  2. Thanks for the kind comments.

    Yes, you can use the programmed microcontroller independent of the LaunchPad and for a mobile application that might make sense. However, you will need to provide at least a minimal circuit board or perf board, a rectifier and power supply. If you are just driving LEDs, then you will need the current limiting resistors, which you would need even if you were using the LaunchPad. So your approach will work.


  3. Terry

    Great show on MRC. I ordered 3 today from TI. Looking forward to trying them out. I will be featuring your blog on our website this week.

    Peter De Keles
    Special Projects Editor
    Large Scale Online

    1. Welcome Peter! Because of their wide bodies, LaunchPads can be used on-board large scale trains. Are there any special projects your readers would be interested in?