That is a REALLY interesting idea... 

Bob has talked in the past about having an "unused" pin that sends out
status info all the time in some special format...

If you send out status data in a serial stream fast enough and continuously,
it should look more or less consistent when used to light the power on LED
on the widget you are making. 

For no extra cost, you get a visible status data stream. 

Of course, you can't read it with the naked eye... Other than to note that
the light goes out or comes on brighter when the uC stops running.

Then the question is what can you use to read it? What if the light pattern
was the same as what a barcode reader would see if it was scanned over an
area? So assuming your customer has a barcode reader connected to his or her
keyboard (as is the case at a lot of POS terminals) then you just tell them
to go to a web page that you have set up, and then point the barcode wand
right over the power LED on your widget. Some JavaScript on the page parses
the data stream, breaks it off in chunks and sends them to you via AJAX. 

Or perhaps IRdA is the better protocol? 

What do PDA's talk in when you "beam" contacts between units? 

At worst, you send them a "visible light to RS232 adapter" which everyone
has laying around right?

On Wed, Jan 23, 2008 at 12:05:24PM -0700, Dwayne Reid wrote:
The other neat trick I'm doing is that one of the LEDs is actually 
spitting out a serial bit stream while it is lit.  

<snip>

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist