Spehro Pefhany wrote:
> At 09:03 PM 1/24/2008, you wrote:
>   
>> It *is* a cool idea.  Someone on the list a few years back mentioned
>> that Hewlett-Packard used this for diagnostic data via a front panel LED
>> display.  Barfed out code version or some such.  I seem to remember that
>> it was done in the 70s or 80s.
>>
>> I considered using it once to extract the data from a datalogger that
>> could not afford to have connectors that were not perfectly water proof.
>>
>> A related idea to this was distribution of software via your friendly
>> television set.  I think the Jeopardy home game that allowed you to play
>> along with the show did this.  They modulated pixels near the bottom of
>> the screen and the home users game equipment picked it up.
>>     
>
> If you wanted to use standard UARTs, suppose you sent one byte at 9600
> baud every 5msec (periodic ISR or whatever) continuously. You send a byte,
> then the complement, which keeps the average brightness constant visually
> since the average over 10msec (100Hz) will be constant.
>
>   
Ooo, I like this one. If the protocol is 8/N/1, 10 bits, then the 
average brightness would indeed be
constant....

--Bob
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