ELECINF344/381

Partie interactive du site pédagogique ELECINF344/ELECINF381 de Télécom ParisTech (occurrence 2011).

Catégories

IRL: Tweets on the laser and DMX

This morning our armadeus board seemed not to want to work properly. We must repare it or use another one.

DMX

We did our first real tests with the DMX yesterday. We are now able to control a light with our DMX board. The information sent to the light can be modified by ZigBee. The ZigBee signal will be generated by a daemon on the armadeus which will listen to requests sent through 0MQ. These features are written but we need to get our armadeus back before performing full tests.
Next step is to use data from the database to select which parameters must be send to the light depending on the tweet we want to display.

Displaying tweets on the laser

Yesterday, we finally displayed a tweet retreived in the database on the laser, with a smooth scroll.
The main daemon, in C, starts by querying the oldest validated tweet in the database, then sends the string to a program that converts it to ILDA frames representing the animation of the scrolling text. As this processing is a bit too heavy to be efficiently done on the board, we decided to offload it on Google AppEngine, which offers great performances ! Whenever we do not have access to AppEngine, the processing is done on the board, but it is really slower. A cache mecanism is being implemented. If you want to use this service, you can find a documentation at irlrose2011.appspot.com. For the moment, it is protected by a password because we need to keep the bandwith and CPU time for our own tests.
Then, the result (a series of ilda points) is sent back to the main daemon through a socket, that tranforms these ILDA points in points that will be displayed on the laser, and passes it through a 0MQ socket to the process handling the laser queue.

IRL is reaching its final rush to the last presentation.

ILDA and Web app
Since the last post we did a lot of tests in real situation, namely with several programs running on the board. We deemed that the operation to translate a text to an ILDA animation tends to be far too slow that’s why we decided to rely on a web app based on the google appengine api for Python. Yesterday, we turned words into action and started to create the web app and a proxy in the card to query the webapp or in case of a failure, redirect request to the embedded slow instance of the program. We did deploy the web app on appspot.com and our first tests tend to confirm that the service is accelerated by a factor of 30 to 60 depending on the load of the board. We did realize a website to present our restfull API to that webapp and we will put it online as soon as possible.

Website
As far as website are concerned, we want to introduce our brand new website. Feel free to comment or share any kind of feedback.

FPGA
We hunted some bugs in our code and yet it works better and we don’t intend to make any kind of fix on it till the presentation.

DMX and additional board
We have contacted TSM and we will be able to try our code with real equipments.
We can communicate with our additional board via Zigbee. We have now to connect this feature with the other parts of the project with 0MQ.

Software FIFO
Our software fifo works, we are putting all the pieces together to make our « driver/conductor/leader » module which will manage all the features of the project.
Today we’ll stick the pieces, it’s a milestone !