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Model Railroad Controller aka Stationary Decoder

Posted: Wed Jun 19, 2013 1:11 pm
by Richard-TX
I just completed phase I of something I call the Roc-Pi.

The Roc-Pi is a servo, LED, and block detector or in other words a multi-purpose stationary decoder that uses SRCP (Simple Railroad Command Protocol) as a communications protocol. While designed for use with Rocrail, it could be used with any good command software that is srcp capable..

The project web page is at
Rocrail is available at

The Roc-Pi is cheaper than commercial decoders. After totaling up everything, the Rocpi costs 1/4 of what commercial decoders cost. Commercial decoders cost about $15 per switch to implement plus the cost of the servo motor. The Rocpi is coming in at about $4 per switch. Less if it is just a LED or lighting controller. The reason is that relays for frog switching are not cheap.

If you are into model railroads and have been looking for a full featured switch or LED controller, this could be it.

For what it's worth.

Re: Model Railroad Controller aka Stationary Decoder

Posted: Mon Jul 01, 2013 10:01 pm
by Richard-TX
I have a web site for the Rocrail-Raspberry Pi model railroad controller project.

It is at

This is a full featured controller that has:
- Servo or LED controllers for switch control.
- Power switching for powering switch frogs and signals.
- Block detection

For those that are not into dioramas (which is what a model railroad really is) there are several programming bits and pieces that could prove useful for other projects. The servo/LED controls, relay controls, and the remote sensor controls use both I2c buses and the SPI bus.

This is a work in progress so changes are happening usually on a weekly and sometimes daily basis.

Please note that this is not a DCC project. What this project does is to offload the DCC bus from handling ancillary control and thus permits full DCC bandwidth to control motive power devices.

For those modellers that use JMRI, tell your JMRI support people to complete the JMRI SRCP implementation.