Adafruit 16x2 LCD black boxes on first row

EL Wire/Tape/Panels, LEDs, pixels and strips, LCDs and TFTs, etc products from Adafruit

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azhao
 
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Joined: Tue Oct 08, 2013 11:50 pm

Adafruit 16x2 LCD black boxes on first row

Post by azhao »

Just hooked up Adafruit RGB Positive 16x2 LCD+Keypad Kit to my PI, everything works fine, no issues. Just one thing seems to be irritating, whenever I re-plug in the power, the first row of the LCD comes up in black boxes while PI is booting, at this point no code is loaded. When I run the python program, the boxes will disappear, text display as expected. I adjusted the potentiometer so that text contrast is high, I think this causes the boxes to show up when powering up. I can also adjust the contrast to low so that I will never see the boxes but then text is near invisible.

Any insight is appreciated.

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adafruit_support_bill
 
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Re: Adafruit 16x2 LCD black boxes on first row

Post by adafruit_support_bill »

This is normal behavior. When the LCD first powers up, it displays the boxes until you tell it to display something else. So until your Pi is up & running, the boxes will be there. As you discovered, these are slightly less intense than the normal text display and you can fine tune the contrast to minimize them.

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