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Thread Closed: Became flame-war

???
04/16/08 19:22
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 		 #153563 - Yes, but how will the system respond?
Responding to: ???'s previous message
Andy Neil said:
Jack Peacock said:
Many ISM band chips have the ability to listen before transmitting on a particular frequency. This can be used for collision avoidance.

As Erik says, that just prevents one slave from starting to transmit while another is already transmitting - it will not help when two (or more) slaves start transmitting simultaneously...


The real question lies in how the response to a collision differs from any other corrupted message.

Now it becomes a protocol issue, doesn't it?

RE



List of 115 messages in thread
TopicAuthorDate
Wireless network            01/01/70 00:00      
   assign address to each slave?(with "jumpers")            01/01/70 00:00      
      Still you wont know which is which?            01/01/70 00:00      
         pay with time            01/01/70 00:00      
            not easy            01/01/70 00:00      
            or pay with money            01/01/70 00:00      
               or pay with money - not a solution            01/01/70 00:00      
                  Inherently not simple!            01/01/70 00:00      
         you cant poll for N number of slaves            01/01/70 00:00      
             automatic            01/01/70 00:00      
               N?            01/01/70 00:00      
                  N? - any            01/01/70 00:00      
         Ho about this ...            01/01/70 00:00      
            how do you propose to do that?            01/01/70 00:00      
               have a look at the picture on the website            01/01/70 00:00      
                  Obviously missing something here...            01/01/70 00:00      
                  dipswitch my butt            01/01/70 00:00      
                     it\'s pretty obvious, isn\'t it?            01/01/70 00:00      
                        first - then            01/01/70 00:00      
                           Once again you're assuming facts not in evidence            01/01/70 00:00      
                              The sample is much larger now            01/01/70 00:00      
                                 example            01/01/70 00:00      
                                    Yes, it is            01/01/70 00:00      
                                 I like that ...            01/01/70 00:00      
            I Don't get it either.            01/01/70 00:00      
               It's reall not that complicated ... but ...            01/01/70 00:00      
                  Still not with you            01/01/70 00:00      
                  Slaves to broadcast their presence HOW?            01/01/70 00:00      
                     Not that difficult            01/01/70 00:00      
                        Thats fine but what if we have            01/01/70 00:00      
                           Then you really do need a database!            01/01/70 00:00      
                              you WILL get in big doo-doo            01/01/70 00:00      
                                 this is absolutely true!            01/01/70 00:00      
                           You\'ll need lots of switches and lots of ports            01/01/70 00:00      
                              totally off the rocker            01/01/70 00:00      
                                 How long, at 8kbps            01/01/70 00:00      
                                    Who on Earth wants to do that            01/01/70 00:00      
                                       One has to set limits            01/01/70 00:00      
                                          It does not have to be manual            01/01/70 00:00      
                                             It has its "baggage"            01/01/70 00:00      
                                                no "significant burden" who cares about 'simpler'            01/01/70 00:00      
                                                   Maybe we need to bring the O/P back to reality            01/01/70 00:00      
                                                      I can't tell            01/01/70 00:00      
                                                         I may be slow today....            01/01/70 00:00      
                                                   ARP possiblities            01/01/70 00:00      
                                                Overhead - but possibly not too serious?            01/01/70 00:00      
                                                   You may be onto something ...            01/01/70 00:00      
                                                      you don't get it            01/01/70 00:00      
                                                         How long would it take?            01/01/70 00:00      
                                                            quicker than what?            01/01/70 00:00      
                                                               Obviously there's a trick involved            01/01/70 00:00      
                                                                  or ...            01/01/70 00:00      
                                                                     no patent ...            01/01/70 00:00      
                                                                        With that scheme you have to skip some            01/01/70 00:00      
                                                                           easy            01/01/70 00:00      
                                                                              No ... it means there's nobody at that one address            01/01/70 00:00      
                                                                                 Not an address, an address mask            01/01/70 00:00      
                                                                                    not likely on low-cost RF            01/01/70 00:00      
                                                                                       of course, but nobody woud dream of sending RF w/o            01/01/70 00:00      
                                                                                          Miracle ? , I differ            01/01/70 00:00      
                                                                                 confound it reat the stuff            01/01/70 00:00      
                                                                        no patent ... And after slaves colliding            01/01/70 00:00      
                                                                           after each 'find' it get faster            01/01/70 00:00      
                                                                              the cheap RF links are typically            01/01/70 00:00      
                                                               Erik, please clarify one point            01/01/70 00:00      
                                                                  If one could devise a suitable RF protocol...            01/01/70 00:00      
                                                                     the key is to know more than is known here            01/01/70 00:00      
                                                                        confound it can't you read            01/01/70 00:00      
                                                                           You're assuming facts not in evidence.            01/01/70 00:00      
                                                                              if a response comes, your code is faulty            01/01/70 00:00      
                                                                                 So ... how does that differ from not transmitting?            01/01/70 00:00      
                                                                                    Richard, Richard            01/01/70 00:00      
                                                                                       Yes, but what SHOULD happen?            01/01/70 00:00      
                                                                                       with a mask of zero any unassigned sign sho            01/01/70 00:00      
                                                                                          What is it you are recommending, Erik?            01/01/70 00:00      
                                                                                             Nothing I feel            01/01/70 00:00      
                                                                                             Reading Erik's mind            01/01/70 00:00      
                                                                                                Address+Mask - an RF twist            01/01/70 00:00      
                                                                                                   let me clarify            01/01/70 00:00      
                                                                                                Russ, I admire your "psychic abilities'            01/01/70 00:00      
                                                                                                   A refinement            01/01/70 00:00      
                                                                                                      yes            01/01/70 00:00      
                                                                                                         Starting over            01/01/70 00:00      
                                                                                                            Russ, you may very well be right            01/01/70 00:00      
                                                                                                   Erik, that is not what was asked for!            01/01/70 00:00      
                                                                                                      whic i would have done ...            01/01/70 00:00      
                                                                                                         Perhaps you\'re not aware ...            01/01/70 00:00      
                                                                                                            1) abd 2)            01/01/70 00:00      
                                                                                             NOT "mask address" but "mask AND address"            01/01/70 00:00      
                                                                        some things you can do on the one-wire channel            01/01/70 00:00      
                                                                           Very tricky indeed            01/01/70 00:00      
                                                                              I do not ASS U ME diddlysquat            01/01/70 00:00      
                                                                           It is absolutly required for my scheme            01/01/70 00:00      
                                                                              That is a non-starter with low-cost RF.            01/01/70 00:00      
                                                                  sorry            01/01/70 00:00      
   OK, here's an idea            01/01/70 00:00      
      collisions avoidance ?            01/01/70 00:00      
         Surely the master needs to know its slaves?!            01/01/70 00:00      
            identifying slaves            01/01/70 00:00      
         I can not help with collisions but..            01/01/70 00:00      
   multimaster via RF            01/01/70 00:00      
      collision recovery            01/01/70 00:00      
         Not a few seconds            01/01/70 00:00      
         Listen Before Xmit            01/01/70 00:00      
            not that urban legend again            01/01/70 00:00      
               Accepted terminology            01/01/70 00:00      
            Collisions will still happen            01/01/70 00:00      
               Yes, but how will the system respond?            01/01/70 00:00      
            Listen Before Xmit ......            01/01/70 00:00      
               if slaves can "speak without being spoken to"            01/01/70 00:00      
   Perhaps you should read this article            01/01/70 00:00      
    A Better Way             01/01/70 00:00      
      There are some internal issues too            01/01/70 00:00      
         frequency hopping            01/01/70 00:00      
            frequency hopping , I have DSSS            01/01/70 00:00      

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