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


MB Led: Working IrDA and colored LEDs.

Algorithm on GLiP block:

Today Guillaume has worked with 9 GLiP blocks, trying our algorithm in order to elect the leader among the network and give positions to each block. He succeed in this when the network is slowly increasing but when all the blocks come in a random way, it is still difficult to have a consistent network. There is still no acknowledge with the IrDA and when some packet is corrupted, the algorithm fails. We have to fix this soon.


Cédric has resolved his problem with UART4&5 for emitting packet. After some tests with Alexis, he found a good value for the resistance(4.7KOhms) to control emission power so that the blocks would communicate only to the neighbors. All potentiometers will be replaced by classical resistances.

LED matrix:

Now I can drive the LED matrix using the new driver TLC5951. I can display a 8×8 pixel on the matrix but I have to fix some problems of intensity. We knew that blue is more powerful than red and green and we try to avoid this problem. For the moment, we can’t obtain a perfect white but I’m in a good way to fix this problem.


Sur le même sujet :

  1. MB Led : First test with MB Led blocks
  2. MB Led et IrDA: paquets, procédure de test…
  3. MB Led: Article post communication challenge.
  4. MB Led: Du hardware au software
  5. MB Led: Firmware, Bluetooth, bibliothèque graphique.

3 comments to MB Led: Working IrDA and colored LEDs.

  • Note that I still haven’t seen any formal description of your algorithm posted here. So I am not able to help you on this as I cannot check the correctness (hand waving and saying « blocks look for the node id of the PING they receive » does not count as a formal description).

  • Florent

    What was the problem with UARTs 4 and 5 ?

    I’m also interested in your algorithm since we tried to define one last year but we haven’t enough time to implement it because of IrDA range problems…
    I guess you’re still using the filters on GLiP IrDA transceivers ?
    By the way, I’ll also be interested in the way you handle acknowledgements, especially how you will avoid loops waiting for an ACK, etc… Do you assume that the communication channel is quite reliable, ie that most packets aren’t lost ? It’s not always the case… *cross fingers* :)

    • Cedric LeN

      It was a problem of initialisation, UART5 was writing into the register of UART4. Now it is fix. :)