Subject:
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Weird LCD problems
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Thu, 22 Feb 1996 00:02:22 GMT
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Original-From:
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David Negro <dln2@IHATESPAMcornell.edu>
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Viewed:
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1716 times
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(Summary - LCD not reading D0 value)
Well the parts finally arrived in the mail for me to start working on my
HB. I have been assembling it step by step to ensure that debugging would
be as simple as possible. I am at the stage where I hook up the LCD and
power up IC. I took my 40x2 line LCD that I used with my miniboard and
hooked it up. Loaded IC and it seemed fine till I rebooted. Instead of
printing Interactive C .... it printed some of the characters wrong. A
quick glance at the characters told me that the low data bit (D0) was low
and by printing test messages to the screen proved me right. So I started
to debug. I spent quite a while checking resistances between wires (for
shorts), voltages etc and reheated some joints with no luck. Anyway to
make a long story short(er) I unsoldered the d0 line and jumpered it up to
+5V. Reran the board and still no luck. I checked the voltage on the
correct pin of the LCD controller chip and they read correctly.
So now I am wondering if this has happened to anyone before? Is there
anything that I can do? Right now, half of the commands and characters do
not work. This is very frustrating! I would rather not have to buy
another LCD and don;t want to wait anymore in building the HB. I am too
far along now!!
Thanks for the help,
Dave Negro
dln2@cornell.edu
P.S. For those mac users out there I have started to port as11_ic to the
mac. I thought that I had it done till I realized that I needed to take
care of the
#include
directive as well. So it will be done as soon as I get some free time (3
tests beginning of next week)
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Message has 1 Reply:
 | | Re: Weird LCD problems
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| David -- Soldering d0 to +5v certainly can't help; it should be connected to the data bus (pin 9 of the 6811, pin 11 of the RAM, and pin 3 of the 'hc373). (see the cpu and mem schematic). With board power off, check continuity among these (...) (29 years ago, 22-Feb-96, to lugnet.robotics.handyboard)
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