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16X2 LCD
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16X2 LCD

by Smoothtalker on Fri Feb 15, 2013 11:44 am

Hey all,

So I just received my LCD screen, made all of the solder connections, nothing (to my knowledge) has been "crossed" while soldering the boards. However, I can only see a very faint image on the screen, and it is 8 "boxes" showing. I adjusted the contrast adjuster, and it is still showing very lightly. there is no active backlight, and when i attempt to run i2cdetect, it comes back showing the screen on 20x (which i think is a good thing). I attempt to run the test script from the install guide, and get an error back stating that it cannot connect/see the i2c device.

Any help would be greatly appreciated. Thanks!
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Re: 16X2 LCD

by adafruit_support_bill on Fri Feb 15, 2013 11:54 am

Post photos of the front & back of the board and we'll check your assembly.
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Re: 16X2 LCD

by Smoothtalker on Fri Feb 15, 2013 2:18 pm

http://imgur.com/Pc7LA7D
http://imgur.com/u1EzHOg

I checked again, and it def seems as though it is all connected correctly. Let me know what you think, thanks a bunch!
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Re: 16X2 LCD

by adafruit_support_bill on Fri Feb 15, 2013 3:28 pm

The solder looks very good from what I can see. Can you post one showing the rest of the front (including switches & chip).
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Re: 16X2 LCD

by Smoothtalker on Fri Feb 15, 2013 4:02 pm

http://imgur.com/4vW2nmI

Thanks for the help!
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Re: 16X2 LCD

by adafruit_support_bill on Fri Feb 15, 2013 4:14 pm

Everything looks good.

Which I2C bus is the device detected on, 0 or 1? Does the example code use the same bus?
Rev1 of the Pi's used a different I2C bus than Rev2, so the example code may need to be tweaked to match.
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Re: 16X2 LCD

by Smoothtalker on Fri Feb 15, 2013 5:45 pm

It is detected on 1. Would you be able to advise me on the code needed to change the output?
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Re: 16X2 LCD

by adafruit_support_bill on Sat Feb 16, 2013 7:26 am

It is descrinbed in the tutorial here: http://learn.adafruit.com/adafruit-16x2 ... y-pi/usage

If you have a rev 2 (512MB) Pi, or if you're not getting anything displaying, it might be due to the I2C bus number change in the Pi hardware. Edit Adafruit_CharLCD.py using a command like "nano Adafruit_CharLCD.py" and change the line
lcd = Adafruit_CharLCDPlate(busnum = 0)
to
lcd = Adafruit_CharLCDPlate(busnum = 1)
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