A very cute hack for a 1-wire LCD panel interface, including power!

[Rob Seastrom]

Michael O'Dell <mo at ccr.org> writes:

> http://www.edn.com/design/systems-design/4427215/One-wire-brings-power---data-to-LCD-module

That's a bit interesting, mainly for the cute trick of parasitic
powering the LCD off the comm line, but 2400 baud is kinda slow.
Non-overdriven Dallas 1-Wire is 16.3 kbit/sec.

There are plenty of circuits out there that utilize the Maxim DS2408
and an HD44780 together, and pre-debugged libraries for writing to
that combination.

I see that the cap they use for parasitic poweer is 0.47uF.  Dallas
1-Wire stuff typically is powered by an 800pF cap.  I wonder if a
1-Wire interface (obviously with fewer stations on the "microlan")
would source enough power to keep the 44780 and the backlight happy.

-r