How to build my own DC Metro arrivals sign

August 12, 2011 7:12 AM

How can I build/buy an always-on DC Metro estimated arrival display cheaply and (reasonably) easily?

I would like a wall-mounted, always-on display that shows the estimated time of arrival for two separate DC metro trains, using information culled from the Metro website: www.wmata.com . Ideally, I'd like to set this up for less than $100. Do the MeFites have any thoughts on how best I could do this?

posted by Mr. Excellent to Technology (9 answers total)

Does $100 include the cost of the display? WMATA has an API if you want to roll your own code, or you could buy one of those $99 Android tablets and install an app.
posted by djb at 7:21 AM on August 12, 2011

Response by poster: Yes, $100 includes the cost of the display. I thought of the Maylong, but its app compatibility so so bad that I'm not sure it would work, and it's not particularly wall-mountable.
posted by Mr. Excellent at 7:39 AM on August 12, 2011

Do you have a dedicated computer available already? If so, you could use an Arduino (or similar microcontroller, I only name Arduino 'cause they're readily available and have USB-Serial onboard) to drive some 7-segment LED displays. Not sure if you could actually get in under $100 including a case, all the hardware, etc, if you don't have some of it kicking around already in the scrap pile, though.
posted by Alterscape at 7:50 AM on August 12, 2011 [1 favorite]

A lot of people do this sort of thing by recycling old laptops. I think the general principle is to separate the laptop at the hinge and hide the keyboard half behind the display half in some sort of frame. Then you can hack something together in your favourite programming language using the API, maybe with a Flash front-end or something if you want it to look pretty. You can set up VNC to the laptop-in-a-frame to give you full remote control over the display.
posted by le morte de bea arthur at 8:13 AM on August 12, 2011

Buy a Chumby and build a little Flash widget that calls their API and displays the data.

Or get an old used netbook (can be a really terrible one, since all it has to do is display a single web page) and build a little web page that regularly makes an AJAX call to their API and displays the data.
posted by zachlipton at 8:46 AM on August 12, 2011

My experience with the WMATA site was that it displayed the scheduled times, not the actual times. When I'd stay late at work I used to try time when I'd leave to minimize my waiting time, and frequently found that the trains were unexpectedly running early or late. This was several years ago, so maybe they've improved the system since then.
posted by Hermes32 at 8:48 AM on August 12, 2011

Honestly, if you're using Metro data I wouldn't bother. I haven't found it to be reliable or accurate.
posted by JoanArkham at 9:23 AM on August 12, 2011 [1 favorite]

My experience does not match that of JoanArkham and Hermes32. Re the actual question, I swear i've seen this in a store, but I cannot remember where. Sorry.
posted by Xalf at 10:40 AM on August 12, 2011

Buy a Chumby and build a little Flash widget that calls their API and displays the data.

Not bad price-wise but way more complicated as a solution than need be. You can grab that data and display it 100% with javascript. Anything that will let you open a web page and display it will do.

So how big a display? You can get an old iTouch for $100 and under. You'll have to turn off the auto-locking and open a page (or actually you could just open a link that is nothing but javascript; see the way the Instapaper bookmarklet for the iphone works) which polls those stations.
posted by phearlez at 2:50 PM on August 12, 2011