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Old February 13th 04, 05:02 AM
Avery Fineman
 
Posts: n/a
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In article , "Tim Wescott"
writes:

Hey! I think I have some of those. Since I'm never going to use them, I
suppose I could part with them.

But first the obligitory assesment of assumptions: Why are LCD displays not
an option? Could you drive an LCD from your PIC? I've seen info on this
from the LCD manufacturers; it looks quite doable from a PIC.


You are asking the wrong person. I was responding to the person
saying "LCDs are not an option."

An LCD display assembly can most certainly be "driven" (input the
ASCII code for the character) from a PIC. That is how nearly all of
the little wattmeters and frequency counters are arranged.

Actual DRIVE for an LCD takes a different waveform for most LCD
panels. Some are 2-level, others 3-level in their waveform voltages.
Research the LCD display alone, without the local memory and
scan-drive hardware. That part is not as straightforward as it looks.

A PIC PROGRAM normally scans through an internal register
content and outputs based on that. Usually there is a small conversion
operation to change the code from 4-bit numeric to 8-bit ASCII. That
scanning-and-outputting part of the program can easily be changed
(if you know how to write with the free PIC development program) to
"strobe" an LED array, segments versus character position.

If you don't know how to change an already burned-in PIC, then you
must have some sort of outboard local memory to hold 4-bit chunks
of numeric data...or convert from 8-bit ASCII to two 4-bit BCD in order
to drive a 7-bar segment decoder-driver that CAN drive a numeric LED.
That requires more ICs, one decoder-driver per numeral. Average power
to light the LED is about the same for any given brightness whether it
is driven on a DC basis or strobed segment v. numeral.

NONE of the above is "trivial" nor any sort of "cake" if you've never
worked with microcontrollers or their development systems before.
Almost ANYTHING "doable" can be done but development time and
resulting learning curves are hard to fund at the home hobbyist level.

For example, I've been working on inventing anti-gravity. Something
keeps holding the project down ...

Len Anderson
retired (from regular hours) electronic engineer person