Computing stuff tied to the physical world

TwitLEDs robot, part 4

In Hardware on Jun 28, 2010 at 00:01

Today’s episode continues the description of a little robot car which “prints” Twitter messages on a glow-in-the-dark surface.

The last missing piece was the Twitter interface. I implemented it in Tcl/Tk using JeeMon.

Here’s the setup we’re using:

Dsc 0002

The idea is to search Twitter every 30 seconds for a specific search term, and then send the message into the air using a JeeLink.

This is the main code, i.e. application.tcl:

Screen Shot 2010 06 27 at 13.02.06

It uses a custom rig (i.e. module) called twitter.tcl to do the generic part, i.e. firing off HTTP GET requests with a query, and reporting results on screen as well as calling a user-specified call-back proc:

Screen Shot 2010 06 23 at 22.58.32

Here’s an example of the output, when left running for a little while – note that only messages containing the text “design” will be picked up:

Screen Shot 2010 06 23 at 23.10.39

This implementation is a bit simplistic. It will truncate each tweet and only send out the first 60 characters (to fit into a single RF12 packet).

But hey… this is proof-of-concept, after all!

Update – the arena wall is ready. Time to try it out!

Dsc 0017

Here’s a video of the TwitLEDs robot, driving around while staying out of trouble… as you can see, it really manages to do so – mostly ;)

That almost concludes this project. Tomorrow, the last installment will be posted, with final photos and videos.