While I haven't built that particular one, I have built a similar design of
Peter's with good success.

There are some possibilities ... Peter relies on timing for the LCD. If
your crystal frequency is higher than the frequency of the hex file you
downloaded, or if your LCD is a little off (common if you got the LCD from a
hobbyist source) then a blank display or a display of all black squares
would be a common result. Check to be sure that the version of the hex file
you downloaded matches your crystal frequency.

Mag's site is incredibly slow and I haven't located the source, but he at
least has the wiring to avoid being dependent on the timing. Whether he did
or not I can't tell without seeing the source. Reading the LCD to tell
whether it is ready, instead of waiting "long enough" is fairly uncommon
because different brands of LCD seem to respond a little differently, but
maybe you just got lucky.

I would try slowing down your clock a bit as a test. This will give you an
incorrect frequency readout, but it would let you know whether timing is the
problem. One thing about LCDs -- there is no such thing as too slow, so if
the only other crystal you have lying around is a lot slower, it will be
fine for the experiment. If it turns out this is the problem, simply
increase the LCD delay in Peter's source.

...

"JJ" wrote in message
...
I built the 4 line LCD version and the program LCD4CNTR.hex doesn't display
anything on my LCD.

http://www.qsl.net/om3cph/counter/summary.html


Funny thing is my circuit works with the program from this site:

http://www.hamradioindia.org/circuits/fcountlcd.php

Anybody know whats wrong with LCD4CNTR.hex?

JJ