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???
12/27/09 18:08
Modified:
  12/27/09 18:09
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 		 #171960 - Some hints...
Responding to: ???'s previous message
Mahmood said:
My new approach is to divide the panel into six sections, each section contains RS485 and a micro, this way the bitstream will be split into 6 bitstreams which are short with less error probability.

This is a good idea.

You could additionally cover the LEDs by a steal grid, connected to signal ground. Even if the grid is large-meshed so that you wouldn't hardly notice it, the amount of shiedling is enormous!

Another way to handle the EMI caused by the panel itself, is, to avoid simultaneously refreshing of all the LEDs. Do only refresh a small number of LEDs at a time, wait some milliseconds, refresh some more and so on. If you refresh the display line by line needing some 100msec for the whole display, for instance, this could even look "interesting"...

Kai Klaas

List of 96 messages in thread
TopicAuthorDate
LED Display Panel reliability            01/01/70 00:00      
   Serial out/serial in            01/01/70 00:00      
   you do not say            01/01/70 00:00      
      TB62706BFG            01/01/70 00:00      
   Decision by majority...            01/01/70 00:00      
   I would use CRC            01/01/70 00:00      
      I think you missed the point            01/01/70 00:00      
         Reading back the parallel outputs then?            01/01/70 00:00      
            actually not            01/01/70 00:00      
               "If" it is identical data...            01/01/70 00:00      
                  Only the bits in error will generate any flicker            01/01/70 00:00      
                     But he wants perfection!            01/01/70 00:00      
                     all the above            01/01/70 00:00      
                        So, there is a chance for flickering after all?            01/01/70 00:00      
                           If incorrectly designed            01/01/70 00:00      
                  trust and trust            01/01/70 00:00      
                  trust            01/01/70 00:00      
                     layout, layout, layout            01/01/70 00:00      
                     Some hints...            01/01/70 00:00      
                        excellent proposal!            01/01/70 00:00      
                           Principle of function...            01/01/70 00:00      
                        Main EMI Source            01/01/70 00:00      
                           Thoughts            01/01/70 00:00      
                              I do not know your part, but ...            01/01/70 00:00      
                                 Duplicate thread            01/01/70 00:00      
                                 Replies            01/01/70 00:00      
                              double posted            01/01/70 00:00      
                              reply            01/01/70 00:00      
                           RC-filtering and Schmitt-Triggers will help!            01/01/70 00:00      
                              response to above            01/01/70 00:00      
                                 Why???            01/01/70 00:00      
                                    maybe today            01/01/70 00:00      
                                       Hardly...            01/01/70 00:00      
                                          no            01/01/70 00:00      
                                             Wild speculations...            01/01/70 00:00      
                                                Mahmood            01/01/70 00:00      
                                                   No fun to poke about in a fog...            01/01/70 00:00      
                                                      The clock on top            01/01/70 00:00      
                                                   yes            01/01/70 00:00      
                                             He's not required to scroll            01/01/70 00:00      
                                                absolutely, but            01/01/70 00:00      
                                          You're right, Kai, but the frequent refresh costs less            01/01/70 00:00      
                                             Again...            01/01/70 00:00      
                                                it is, indeed!            01/01/70 00:00      
                                                   not only then            01/01/70 00:00      
                                                      PWM with the TB62706??            01/01/70 00:00      
                                                         YES, of course there is            01/01/70 00:00      
                                                            Yes, I understand, but...            01/01/70 00:00      
                                                               Good question            01/01/70 00:00      
                                                                  Digital potentiometer?            01/01/70 00:00      
                                                                     the problem here is            01/01/70 00:00      
                                                                        It seems they can be hooked together...            01/01/70 00:00      
                                                                           Look at this too...            01/01/70 00:00      
                                                                              Ok, then show me ...            01/01/70 00:00      
                                                                                 And write?            01/01/70 00:00      
                                                                                    :)            01/01/70 00:00      
                                                                                 Mahmod doesn't have multicolor LEDs!            01/01/70 00:00      
                                                                                    well, what is this then?            01/01/70 00:00      
                                                                                       Question for Mahmod            01/01/70 00:00      
                                                                                          Looks like...            01/01/70 00:00      
                                                                                          Yes            01/01/70 00:00      
                                                                                       Why from the same chip???            01/01/70 00:00      
                                                                                          limiting color choices to 'per chip'            01/01/70 00:00      
                                                                                             What flexibility?            01/01/70 00:00      
                                                                                                well, if ...            01/01/70 00:00      
                                                                                                   Dials            01/01/70 00:00      
                                                                                                      just to clarify            01/01/70 00:00      
                                                                                                         Length of chain shouldn't really matter            01/01/70 00:00      
                                                                                                         Single color LEDs            01/01/70 00:00      
                                                                                                            Vled only            01/01/70 00:00      
                                                                                                            Two questions...            01/01/70 00:00      
                                                                                                               Answers            01/01/70 00:00      
                                                                                                                  What range?            01/01/70 00:00      
                                                                                                                     Blue            01/01/70 00:00      
                                                                                                                        I would do it like that...            01/01/70 00:00      
                                                                                                                           thanks            01/01/70 00:00      
                                                                                                                              Why?            01/01/70 00:00      
                                                                                                                                 Board to Board Hopping            01/01/70 00:00      
                                                                                                                                    Of course...            01/01/70 00:00      
                                                                                                                                    one advantage, the other is ..            01/01/70 00:00      
                                                                                                                                       Not 40xx Chips As Generic Family            01/01/70 00:00      
                                                                                                                                          Clock skew?            01/01/70 00:00      
                                                                                                                                             Still very very helpful...            01/01/70 00:00      
                                                                                                                                                There are lower-resistance solutions            01/01/70 00:00      
                                                                                                                                                   On-resistance is beyond any doubt...            01/01/70 00:00      
                                                                                                                                                      I've used several '66s            01/01/70 00:00      
                                                                                                                                                         without any opinion of the 4066 option            01/01/70 00:00      
                                                                                                                                                      I didn't intend to suggest that it was wrong, Kai            01/01/70 00:00      
                                 All the filter is supposed to do is limit the slew rate            01/01/70 00:00      
                                    no, not the slew rate            01/01/70 00:00      
                                       Scope plot?            01/01/70 00:00      
                                          Maybe later on            01/01/70 00:00      
                                       Yes, that's true, but his worry was about his clocking            01/01/70 00:00      
                                          Great            01/01/70 00:00      
   suggestion            01/01/70 00:00      
   Problem Solved!!!!!!            01/01/70 00:00      

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