some sign code

Michael Barton — Fri, 03 Oct 2008 16:54:44 +0000

So, what I’ve got here is my implementation of the favotech sign’s protocol in python. As I’ve mentioned, it’s horrible. From what I can tell, the sign supports basically the same protocol over TCP, UDP, and serial. I’ve been using UDP over a crossover cable from a whitebox with two NICs, and that’s worked fine.

I’m using it inside a twisted app, mostly for all the batteries it includes. I have a UDP server class that inherits from this class, but implements its own send_to_sign method. This layout made reusing the code for different connection media a breeze. Basic usage then looks something like this:

   self.test_reset()
   self.pause()
   self.time_sync()
   self.set_frame_count(3)
   self.set_text(0, '{y}OH HAI')
   self.set_text(1, 'I AM {f}THE{/f} SIGN')
   self.set_text(2, '{0}{ma} {dd}  {12}')
   self.resume()

To dumb down the interface, a frame count of n actually creates a playlist containing n two-letter filenames, 'AA’…’ZZ’. Calling set_text with a frame ID then sets the text of the corresponding file. The set_text method has a dead simple markup language it can use to set text colors and stuff.

More to come, probably…

it's saying hi

Michael Barton — Mon, 01 Sep 2008 05:17:18 +0000

Is that an LED sign on my desk? I believe it is.

It’s a FavoTech model I picked up on eBay that can be programmed by ethernet, USB, serial and IR. My weekend project has been reverse engineering enough of its network protocol to control it programatically. The protocol is all binary stuff over UDP, but I’ve made quite a bit of progress in deciphering it.

It’s not all mai tais and yahtzee, though. I somehow broke the sign so that when it first boots up, it spams the network with constant ARP packets until I’ve uploaded a playlist. I think it’s because I removed the playlist on the flash drive, but I haven’t figured out how to get one back on there yet. Against all reason, it’s apparently not “select the flash drive then upload a playlist”.

I know it has a speaker, because it’s forever beeping when it resets. I just haven’t figured out any message I can send it to make it beep on cue. I emailed their tech support but haven’t heard back yet.

I’m not even being original here – one of my co-workers has a nearly identical LED sign that used to stream news feeds and OA scores in our office.

It’s pretty fun, though. And I think there’s a lot of neat information you could convey in sign form. The only limit is my imagination! Oh, hell.

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some sign code

it's saying hi