casemod:
bperrybap:
Actually, I"m with don on this one. I've never used a scope to debug a simple connection issue.
When writing and debugging the actual low level code to drive a piece of h/w I've
sometimes used a logic probe to check signal levels, and often a logic analyzer to verify
signals and timing.
And your point is?
A scope is not particularly a good tool to debug something like this.
A scope is typically used for looking at analog signals not for simple
digital signal levels.
Plus scopes (at least good ones) are much more expensive than other tools
that are better suited for looking at digital signals.
In close to 40 years of embedded s/w development I can probably count the times
I've needed a scope on 1 hand. And all those were all related to subtle analog ringing issues.
(Now for brining up a new high-speed h/w design, that is another story, but we aren't doing that here)
In this situation, we are working with known working s/w, and the signal transitions
going from the AVR to the LCD are not very fast so analog noise is not likely to be an issue.
Assuming the LCD isn't damaged, then all that is left is wiring/soldering
issues.
Assuming you did want to use a scope as expensive logic probe, then what?
The advice you gave was to just look at the data lines.
Just looking at the data lines isn't going to tell you much, you may see a few lines
wiggle and still be no closer to knowing what the issue is.
Plus it requires a substantial amount of knowledge to know what sort of "wiggling"
on the data lines would be normal.
From the final description, pin 5 (lcd R/W) was the issue.
So using a scope to look at the data lines wouldn't have helped.
In this, case, just as Don and I suspected, from seeing so many of these LCD issues,
the issue was a wiring/soldering issue and often those issues can be seen from
visual inspection which is why we asked for photos of the actual setup.
casemod:
bperrybap:
I'm also guessing that the photo of the LCD we've seen so far is a stock photo
and not a photo of the actual LCD being used.
The OP gave a description and backed up with a photo. Unless he was lying (why would he!?) this is a good hint.
So again, whats your point?
My point is that people often post photos of "their LCD" or similar products from photos on the web
that look like what they are seeing on their LCD instead of photos of their actual h/w being used.
It isn't that they are lying. No. They are just posting a photo that shows the same visual
rather than showing it on their h/w.
The solder joints in the photo all look really good in the photo we were shown,
plus the link has a look of being a product page since it is off on a commercial site
vs a personal photo.
That is what lead me to suspect it might not be a photo of the actual LCD in use.
Easy enough to settle.
beingobserver, is the link to the photo of the LCD you posted the actual LCD
you are using or was it a photo from a product web page?
--- bill