Issue with RGB LCD Shield 16x2

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mwomack
 
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Issue with RGB LCD Shield 16x2

Post by mwomack »

I recently purchased this RGB LCD Shield with a 16x2 negative display:

https://www.adafruit.com/products/714

I soldered it altogether as per the assembly instructions (photos attached) and I am using the sample program that comes in the "Adafruit-RGB-LCD-Shield-Library-master" (see https://codebender.cc/sketch:157836).

The problem I have is that the buttons change the colors per the example program, but there is no text displayed. No Hello World or the number of milliseconds since start up. Just a blank screen that I can change the color of using the buttons.

I had some issues trying to fit the LCD screen onto the shield with the stackable headers, so I had to have the LCD pin headers at a slight angle, but I think the connections are good. I resoldered all of the pin connections to the LCD screen, both on the board and on the LCD screen. I resoldered all of the pins of the MLP23 chip. I'm just a novice solderer, but I think the connections look good. I don't think there are any shorts at least. Still no luck. Same behavior before and after.

Any suggestions? Are there particular pins/connections I can look at that are related to the text display?

-Mark
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mwomack
 
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Re: Issue with RGB LCD Shield 16x2

Post by mwomack »

I should also mention that I tried my shield with two different Uno boards, same results of no text displayed, just the background color.

-Mark

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adafruit_support_mike
 
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Re: Issue with RGB LCD Shield 16x2

Post by adafruit_support_mike »

Have you adjusted the contrast potentiometer? That needs to be cranked most of the way to one side before the LCD starts to show output.

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mwomack
 
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Re: Issue with RGB LCD Shield 16x2

Post by mwomack »

Yes, that was it! I adjusted the potentiometer and the text appeared! Glad to see I could handle the basic soldering after all.

I missed the Adjust Contrast portion of the tutorial. Argh.

Thank you!
-Mark

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adafruit_support_mike
 
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Re: Issue with RGB LCD Shield 16x2

Post by adafruit_support_mike »

That catches everyone the first couple of times. ;-)

Glad to hear it's working for you. Happy hacking!

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