Blue LCD with i2c backpack is flashing

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techbird
 
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Blue LCD with i2c backpack is flashing

Post by techbird »

I've worked with IC2 on other devices (8x8bicolor lcd, 7 seg display etc) but after connecting up a Blue LCD #181 with the i2c backpack (292)
Using these instructions (http://learn.adafruit.com/i2c-spi-lcd-b ... ect-to-i2c) I've got things hooked up with LiquidCrystal library.

On startup, using example "Hello World_ic2" I"m getting flashing display but no text.
The instructions say:
"If you see the backlight blinking that means your connection to the i2c port is OK but the contrast is too low or too high, or the LCD data pins are not solidly connected."

But there is no contrast control. The instructions don't show a connection when using the ic2. Is there a software control for contrast.
I've triple checked the 16 pins of solder connections. and hook ups.

This is a departure of hooking up traditionally with lots of wire and a pot. Or using the 16x2 shield kit

At this point I'm at a loss of what to do next.

Anyone get this working?

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techbird
 
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Re: Blue LCD with i2c backpack is flashing

Post by techbird »

RESOLUTION!

Ok, this is crazy. But I'm glad to have found it. The i2c board for LCD's is slightly different in that it includes a tiny contrast adjustment. I glanced over and didn't notice!

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adafruit_support_mike
 
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Re: Blue LCD with i2c backpack is flashing

Post by adafruit_support_mike »

Yep, it's the tiny little potentiometer at the end of the terminal label 'DAT'.

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