At 01:31 PM 12/11/97 +0100, Alessandro Zummo wrote:

[regarding using a PWM signal from a PIC, integrated by a low-pass RC
filter, to set the contrast voltage for an LCD]

>only a question: while the pic is pwmming, he can't obviusly do
>any other thing..... ?

Good point.  However, nothing says the PWM signal has to be there
continuously.  PWM for a half dozen cycles to get the integrator up to
voltage, then tri-state the output (make it an input).  No load (other than
that from the LCD, which is minimal) means it should hold the voltage for a
while.  Just come back every now and then when you have CPU cycles to spare
and PWM for a while, then tri-state again.  Increasing the C in the RC
filter also helps.

 - Rick "Modulating a PWM output... hmm..." Dickinson
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