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Erik Malund
02/01/12 13:41
  02/01/12 13:57

Read: 498 times
Mt Airy, Nc

#185764 - I think you are making excuses
Responding to: ???'s previous message
Yes, I know that solution. However, I don’t want to use Low-Active Design.
then, I know of no micro you can use. Any micro known to me will be either high or 'open' ("input") on power up. and, since 'open' match "cold solder" that will not satisfy you.

When I/O pin is logic-1. Due to cold solder, PNP transistor’s Base pin will be logic-0 and RELAY ACTIVE… (Who can warrant that such an event won’t happen.)
the transistor that drives the relay may short (Who can warrant that such an event won’t happen.)
the the relay contacts may 'weld' (Who can warrant that such an event won’t happen.)

BTW if the connection to the PNP base is open the PNP will not conduct and RELAY INACTIVE.

Low-Active design is not secure for that kind of circuits.
as above, no design is secure. The only difference is where the insecurity comes from.

In other way, I can be passed up power-on port situation in data sheet. But this mean is not “ATMEL true”. I think ATMEL must have done selectable internal pull-up resistors.
they may in certain derivatives but not in the "plain vanilla"

also, how will "selectable internal pull-up resistors" help you?

If there is not software solution,
If ATMEL won’t do selectable internal pull-up resistors,
If ATMEL won’t solve that very easy problem,

I doubt very much that Atmel - or any other micro manufacturer - will modify their designs to satisfy you.

I think you are making excuses for not having read the datasheet before you designed.


List of 34 messages in thread
Power-On Port Status Problem      Adam Blue      01/30/12 08:42      
   Wrong idea      Per Westermark      01/30/12 08:48      
   you will not      Erik Malund      01/30/12 08:49      
   you are not the only one      Erik Malund      01/30/12 09:18      
   ATMEL be ashamed      Adam Blue      01/30/12 15:05      
      No, YOU should be ashamed...      Kai Klaas      01/30/12 16:15      
      Nonsense!        Andy Neil      01/30/12 16:46      
      PIC Does so      Neil Kurzman      01/30/12 23:08      
         Oh really??      Michael Karas      01/31/12 07:46      
            "Glitch" in the sense of kind of "setback in a plane"?      Kai Klaas      01/31/12 10:19      
   Try These Ideas        Michael Karas      01/30/12 17:21      
   "Glitch"      Adam Blue      02/01/12 13:12      
      what is not “ATMEL true”.      Erik Malund      02/01/12 13:37      
      I think you are making excuses      Erik Malund      02/01/12 13:41      
      Oh, boohoo!        Rob Klein      02/01/12 14:04      
      What a bunch of fatty sausage...      Michael Karas      02/01/12 14:59      
      "very easy problem"      Andy Neil      02/01/12 15:02      
   Power-On Glitch      Adam Blue      02/01/12 15:40      
      Nonsense - again      Andy Neil      02/01/12 16:28      
      Please explain what the "power-on glitch" is ...      Richard Erlacher      02/01/12 19:26      
      Into The Frying Pan        Michael Karas      02/01/12 20:52      
      Power-on problem...      Kai Klaas      02/02/12 05:55      
      You are still blaming the tools      Per Westermark      02/03/12 05:55      
   Design the hardware first.      David Prentice      02/02/12 07:21      
      do not Design the hardware first.      Erik Malund      02/02/12 07:30      
   Power-On Glitch      Adam Blue      02/02/12 15:07      
      that you had the worst possible reset circuit      Erik Malund      02/02/12 15:59      
      RC-reset...      Kai Klaas      02/02/12 17:20      
      Sorry, double post, don't know why...      Kai Klaas      02/02/12 17:21      
         No, you're not the only one      Richard Erlacher      02/02/12 21:12      
      Would I Hire?      Michael Karas      02/02/12 22:44      
         incidentially      Erik Malund      02/03/12 07:09      
   Power On satus Problem      Satish S Munot      02/29/12 10:16      
      echo, echo, echo      Erik Malund      02/29/12 10:30      

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