AVR-Chat

Richard,
Are you sure the short is in the design files?  I've had numerous boards (usually production boards), that come back with unexpected shorts between traces.  These result from "under etching" at the board house, which is why they offer electrical testing.  

Of course, it's the only industry I can think of that charges extra if you want them to build it right!  Can you imagine ordering a pepperoni pizza; finding onions instead of pepperoni; and the waiter says "you didn't pay for 'ingredient inspection'"!

Regards,

Tim Gilbert
JEM Innovation Inc.
303-926-9053 (office)
303-437-4342 (cell)
720-890-8582 (fax)
www.jeminnovation.com
www.pdksolutions.com

  ----- Original Message ----- 
  From: Richard Cooke 
  To: AVR-Chat@yahoogroups.com 
  Sent: Tuesday, November 13, 2007 6:43 PM
  Subject: [AVR-Chat] Re: Debugging a ATmega48V - what's going on? - I found it!


  Hi Tim,

  The crazy thing is I did run the DRC before sending in my Gerber
  files. I still don't know what happened.

  Richard Cooke
  Lake Forest, CA USA

  --- In AVR-Chat@yahoogroups.com, "Tim Gilbert" <tim@...> wrote:
  >
  > Richard,
  > As a long time user of Eagle (and its goofy arrogant German
  interface), I'd recommend that you always run the DRC (design rule
  check) before making your Gerbers. It will warn if the board doesn't
  match the schematic; I can't tell you how many times I've caught
  something at the last minute.
  > 
  > Tim
  > 
  > ----- Original Message ----- 
  > From: Richard Cooke 
  > To: AVR-Chat@yahoogroups.com 
  > Sent: Tuesday, November 13, 2007 11:13 AM
  > Subject: [AVR-Chat] Re: Debugging a ATmega48V - what's going on? -
  I found it!
  > 
  > 
  > Hi Folks,
  > 
  > First, I want to thank every one for their good suggestions in trying
  > to track down this bug. Just goes to show you that two (or more)
  > heads are better than one.
  > 
  > John Samperi and Cat win the prize. If either one of you is ever in
  > town lunch is on me. Turns out John's suggestion lead me to measure
  > the Vcc and it did indeed fall to 1.3V (from 3.3V) as soon as I single
  > stepped to the offending line in the debugger. I had run out of ideas
  > so I revisted the RF section per Cat's suggestion. Turns out I made a
  > layout error and there was a short between the radio output and the
  > antenna. Looking back at the entire episode it makes perfect sense -
  > the bug only appeared when the radio went into TX mode. I just wasn't
  > smart enough to see it.
  > 
  > Turns out that Eagle will allow you to make a connection while laying
  > out the PCB even if the schematic doesn't. I've just recently
  > switched to Eagle from Winboard so I'm still learning how it does
  > things. Winboard wouldn't allow you to connect two components if they
  > weren't connected in the schematic. Now I know so I'll be more
  > careful next time.
  > 
  > Thanks again for all of your help. I'd still be staring at the board
  > without your help.
  > 
  > Richard Cooke
  > Lake Forest, CA USA 
  > 
  > --- In AVR-Chat@yahoogroups.com, "Cat C" <catalin_cluj@> wrote:
  > >
  > > Are those pins turning on some RF stuff that being differently
  > matched might 
  > > use more current?
  > > Did you validate the new RF design some other way, so you really
  > have no RF 
  > > shorts (not just DC)?
  > > 
  > > If you power from the Dragon USB... anything above a certain power
  > might 
  > > turn it off.
  > > 
  > > Cat
  > > 
  > > __________________________________________________________
  > > Send a smile, make someone laugh, have some fun! Check out 
  > > freemessengeremoticons.ca
  > >
  > 
  > 
  > 
  > 
  > 
  > [Non-text portions of this message have been removed]
  >



   

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