FastClock Shield

From SPCoast

 Status: Waiting for prototype PCB boards...

This is a prototype Arduino shield for a Loconet fast clock. In the "serious" model railroad world, part of the fun of playing with trains is using them as part of a collaborative role playing game called "operations". When "operating" a layout, a group of train nuts (uhmmm, what else would you call us?) gather together and pretend they are making up trains, moving them along the proper routes and delivering the right cars to the right places - all according to a "real world" inspired schedule.

Since our model layouts are much smaller than the "real" railroads (being stuck in small garages & basements rather than taking up, say, all of Northern California...), we tend to compress things to fit. 10' of track becomes "a mile", a half dozen businesses and a few houses becomes "a city", and a days work becomes "a few hours" - after all, it is a hobby, not an obsession :-)

Fast clocks are part of how we fit a whole 12 or 24 hour day of operation into an evening of role playing - just have the clock run at 4 or 6 or 10 times as fast as usual, so an hour becomes just a few minutes, and the run across the layout now takes "all morning" instead of "less than an hour" :-) Commuter trains running on a 1/2 hour schedule now roll out every 10 minutes, the 9am Daylight and the 9pm Starlight both get run before lunch, etc...

This fastclock is intended to drive a 4-digit LED display based on the Loconet FastClock synchronization packets generated by Digitrax command stations, JMRI and/or other fastclock "time sources". Designed around a SparkFun-supplied display, the board can also be used to drive larger units (see the examples at right from Huangqiangbei SEG Plaza Electronics Mart cool animated map...) with some additional wiring...

It is based on my standard Loconet interface and includes a daughterboard for remote mounting a LED display - either the sparkfun COM-09480 or (with your own wiring) one of your own choosing. This project is a collaboration with Michael Brown, and started with his desire to "put together some fast clocks on the cheap for use with a Loconet system". I designed the board to be usable without the Loconet interface, so it can also serve as a platform for OpenLCB experimentation.

The orange jumper in the bottom picture is a simple digitalRead input tied to digital pin 13 used in the code to run either a slow or a fast "clock" (5s/min or 1s/min)

The following files can be downloaded

• Eagle schematic and board layout
• Gerber files for use with BatchPCB and SeeedStudio
• Mouser.com EZ-Buy parts list DOES NOT INCLUDE SparkFun LED display COM-09480
• Arduino sketch to drive display

 Update:  Jan 2011 Ordered a set of prototype boards from Seeed, should be here by end of January

 Update:  Feb 2011 Got the prototype boards, built one up, verified it works electrically, 
                             sent some off to Michael

 Update June 2011 Finally found time to code up a simple sketch to drive the display 
                            no Loconet/OpenLCB interface at this time, but it should be easy to add: 
                                 remove fake "pretend to be a clock" counting code, 
                                #include Loconet.h, 
                                init things,
                                look for packet each loop, 
                                decode fastclock stuff...
                           The 180 ohm resistors on the LED mez board could be replaced with 
                           lower values to brighten the blue display