I am considering building an LED array to hang on the side of a tower.
LEDs would be attached to a lightweight grid.  The grid spacing is to
be determined.  Initially the LEDs will be white for night viewing.

The array may end up being 50 by 30 feet ( height / width )

I was considering using a chip such as the DS2408 which provides
one wire communication support and 8 I/O pins.

Then I thought that it might make sense to use a PIC MCU instead.
The idea would then be a low cost PIC with 8 GPIO and some kind
of multi-drop or pass-through communications.

Power to the MCUs and LEDs might be on separate feeds.

JAL seems like a good language to use.

The number of LEDs to be individually controlled would be in
the range of 1500 to 6000.  Updating all the LEDs once per
second would be cool.

#1   What would be the best communications scheme and method
of identifying each MCU uniquely ?   Would it be better to use
fixed IDs or dynamically assigned IDs ?

#2  Would it be a good idea to find a PIC MCU with a built-in
supply regulator ?   The distribution of power to MCUs and LEDs
is an interesting one.  Should I use high voltage / high
frequency AC to distribute the power ?  This would mean smaller
copper wires and transformers.

#3  Since I want as little "stuff" hanging on the grid as
possible I imagine the MCU should have a built -in oscillator.


#4  A low cost way to drive the LEDs ( which are not chosen yet )
might be a FET per LED.    I am trying to think of a clever way
to control the LED current.  One idea was to produce *10 volts
peak AC from the output of a step-down transformer , put a diode
in series , an inductor in series , the LED and the FET to common.
I could switch the FET for a given time and then switch it off.
The total amount of current would depend on the on-time.
Maybe it would make more sense to use a resistor in series rather
than the inductor.

( * The 10 volts is chosen to give a starting point to the design )

#5  The ability to remotely load new code into the MCUs  could
be useful.  It would not have to be a fast process.

When I was using the Microchip MCU parametric search, I did not see
a filter for on-board power regulator.  Did I miss something
obvious ?


OR can all this be bought off the shelf ?

Gus


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