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Topic: Is something wrong with my LCD screen? (Read 2 times) previous topic - next topic


Mar 12, 2011, 01:14 pm Last Edit: Mar 12, 2011, 01:23 pm by floresta Reason: 1
You have not connected the enable pin (LCD pin 6) and you have  not grounded the R/W pin (LCD pin 5).


P.S. I would have seen this earlier if it were in the 'Displays' forum.


floresta - looks like I did have a wiring error in the video. I've fixed it since and I still get the same behavior

polishdude20 - I've tried both of the things you've suggested, and I still get the same thing.

I've uploaded another video of my setup, which is now modeled after your tutorial, in case it makes any difference.


Thanks for your help.


Mar 12, 2011, 04:49 pm Last Edit: Mar 12, 2011, 04:52 pm by floresta Reason: 1
These first two are red herrings, they won't help or hurt:
The display is 20X4 instead of 16X2. I've tried adjusting the lcd.begin statement to account for that but I get the same results.
You get the same results because the current LiquidCrystal library only checks the second value, and it only checks to see if that value is '1' or greater than '1'.

I tried it with and without the setCursor call, same behavior.
You do not have to set the cursor.  It is set to 0,0 when the LCD is initialized.

try taking away the counter and just have the word hello world displayed.
This is not a bad idea.  Having changing data in an initial program is a poor choice when it comes to troubleshooting.

For a moment I thought my LCD might not be broken, but that's what it's looking like to me.
I doubt that it is broken.

Your contrast may be set too high.  If you have a voltmeter you should find that the voltage at pin 3 is less than 1 volt when the display is correct.

You have used way too much solder - check both sides of the board for solder bridges between LCD pins.  Also, the connections to several of the pins on the LCD module don't look too good, especially 4, 5, and 11.



I just thought of this:
I also tried hooking it up in 8-bit mode and I didn't get anything different,
If that was before you corrected the E and R/W connections then it would be a good idea to try it again.  There have been more than one instance of timing problems lately, possibly due to displays that slower than normal.  The 4-bit mode seems to be less tolerant of this condition.



So I'll be the first person to tell you that my soldering skills are abysmal. I'm a software guy, and I haven't done much soldering in my time. I decided to just re-do my soldering, and look:


Brilliant! I should be able to apply it to my project. Thanks again for all your help.

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