I was browsing the web looking for examples of NTrak modules, the standard for small N scale modular model railroads, when I came across the website of the Piedmont ‘N Southern club out of upstate South Carolina. While there is a lot of good NTrak information there, what got me really interested in their site was the detailing of their setup. They have some pretty extensive documentation with pictures of the DCC equipment they use including Digitrax, JMRI, and yes, even JMRI running on a Raspberry PI.
To quote the website, they use the “RaspberryPi as an access point and JMRI computer. To simplify the use of JMRI and WiThrottle, we have a tiny RaspberryPi computer which runs JMRI, and also acts as a WiFi access point. So our members can simply turn on main power, and the RPi will startup and load JMRI. Within 2 minutes, members can connect and start running trains from their devices. The RPi has no screen or keyboard, so it can stay nicely out of the way in the electronics box.”
Interesting stuff, and I definitely need to go see it all in operation some time soon.
The Maker Movement is really gaining steam these days. From “Make Labs” down the road to Arduinos in every RadioShack, the maker phenomenon is spreading like wildfire. For some this grassroots movement to create new things is hard to understand. That is where Mark Hatch’s book “The Maker Movement Manifesto” comes in to play. Published by McGraw Hill and subtitled “Rules for innovation in the new world of crafters, hackers, and tinkerers”, this book is a 40,000 foot management overview of the changing world of innovation.
Hatch is the CEO of TechShop, a maker space where inventors and innovators can go to test out ideas, use the available equipment, and create the projects of their dreams. In this book he uses the experiences he has gained at that location to follow the path of ventures such as DoDoCase, the iPad case manufacturing company, to Square and Oru Kayak.
The examples and case studies are the backbone of the book. What we are seeing here is the maker experience from the business side. In contrast to a nuts-and-bolts book like “Zero To Maker” by David Lang, The Maker Movement Manifesto is an enthusiastic relation of the maker psychology and the perks of approaching manufacturing in a new way. Whether it is shortened designed times, less need for out-side investment, or a more hands on and adaptive method of the product evolution, Hatch discusses the big picture issues. Issues like the correct software to use, the different microprocessors to consider, and the implications of the various styles of 3-D printers are beyond the scope.
If you are new to the field, if you need to know why people are excited about the maker movement and why it is being compared to the birth of the Internet, then this a great book. The style is friendly, the examples inspiring, and the read enjoyable. But if you have a grasp of why you want to be a maker are are looking for a guide on how to be on, you might be better off with “Zero To Maker”.
OK, so another piece of the control puzzle may be falling into place. I purchased two small 5v relays off eBay. These should allow me to use the outgoing signals from the Raspberry Pi to control things like power to switches, signals or other on-off devices. Since the relays totally isolate the Pi from whatever is being controlled, I don’t have to worry about too much voltage flowing back into the Pi and killing it. The biggest problem, and something I need to work out, is that these are really meant to be triggered at 5 volts where the Pi only puts out 3.3 volts. I have heard it will work, but only testing will tell.
And now my little Raspberry Pi has wi-fi. This is the next step in moving towards a self contained JMRI unit. I chose the Edimax EW-7811Un USB wireless adapter because it is cheap and very small. So small that it doesn’t block the second USB port, doesn’t stick out very far, and doesn’t require extra power or place an heavy draw on the Pi.
All I did was power down the Pi, insert the little Edimax unit, reboot the Pi, and then go into a VNC session over the connected ethernet connection. I did it that way because I don’t have a monitor or keyboard directly connected, and the graphical setup for the wi-fi adapter is much easier than doing it from the command line.
You can see from the screenshot at left that the graphical wi-fi setup is dirt simple. Just launch it, have it scan for your SSID (or type it in yourself if it isn’t broadcast), select it and enter your wireless password. That’s it. Or, at least that is for supported devices that have the drivers built–in to the Raspbian operating system build. Again, that is one of the reasons I purchased this one – so I wouldn’t have to mess with finding driers. And at just $13, I wasn’t going to get anything any cheaper anyway.
So now I can take the Ethernet cord out, move my Pi anywhere in the house, and continue work on the project via wi-fi. Next will be a small external display to show some machine stats (cost of LED display ~$6.00 off eBay) and then work on the actual machine to track DCC interface.
Might as well add in here too that I went to a lecture put on by the South Carolina Historical Society this even. The first half was on railroad first of SC, such as The Best Friend. The second have was about historical resources available in the Library of Congress from an engineering survey and audit of all the railroads in the US done around 1920 or so. Good stuff, and great references for modeling. I am going to try to get in touch with the two speakers to not only get more information for my modeling of the Seaboard Air Line Railroad in this area, but also for further information and resources to add to my Charleston Rail site.
Well, thanks to the help of some instructions and code I found on line cleverly named “JMR-PI“, I now have JMRI up and running on my Raspberry Pi. Truth be told, it really didn’t take much effort on my part. All I had to do was follow the instructions Matthew Macdonald-Wallace put up on the GitHub repository. If I am able to make any additions to contributions to the project, I will also put them up online.
But, now that JMRI is up and operational, I need to work on the Pi to track interface, be it SPROG or Digtrax PR3 or whatever. No reason to delay and no time to waste.
Oh, also just a quick not that I did purchase a case for my Pi. I just can’t stand to have it sitting out all nekkid-like. I don’t know if this will be its permanent home, but it was cheap and also came with some heat sinks for the main chips.
I got it off eBay for less than $9 including the case, heat sinks, and shipping. Can’t beat that even if I don’t end up using it for anything more than initial protection and prototyping.