Positive 16x2 RGB LCD not working, no backlight
Moderators: adafruit_support_bill, adafruit

Re: Positive 16x2 RGB LCD not working, no backlight

by adafruit_support_bill on Mon Jan 28, 2013 4:53 pm

To view the board files, you need the Eaglecad package. It is a free download.
http://www.cadsoftusa.com/download-eagle/freeware/
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Re: Positive 16x2 RGB LCD not working, no backlight

by wallykissel on Tue Jan 29, 2013 11:58 am

Never mind. Downloaded 'EAGLE' to read the schematics.
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Re: Positive 16x2 RGB LCD not working, no backlight

by tnagy14 on Tue Jan 29, 2013 12:57 pm

I believe I have traced the problem down to a short somewhere between the SDA and SCL pins. The only active component connected to those pins is the IC. I am planning to buy one from digikey and try it out. In the mean time, is it possible to exchange the LCD with the missing capacitor. Note that I bought this kit through Maker Shed so does it need to be returned to them?
Thanks,
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Re: Positive 16x2 RGB LCD not working, no backlight

by adafruit_support_bill on Tue Jan 29, 2013 1:32 pm

We can replace the display for you. Contact support@adafruit.com with a link to this thread and request a replacement RGB LCD for your shield.
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Re: Positive 16x2 RGB LCD not working, no backlight

by wallykissel on Tue Jan 29, 2013 4:28 pm

wallykissel wrote:
wallykissel wrote:
adafruit_support wrote:@tnagy - The schematics and board files are all here: https://github.com/adafruit/Adafruit-RGB-LCD-shield
btw: What processor are you connecting this to?

@wallykissel - It sounds like an i2c communication problem. I am not familiar with the Funduino, but we have seen problems with some of the clones. If you post photos of the front & back of the board, we can check your assembly.


Post photos of the back? Sounds like a de-soldering challenge. I will borrow a friends stock UNO tomorrow and try the 'Hello World' demo.

- Wally


I'm open for suggestions on how to view the .brd and .sch files. @ https://github.com/adafruit/Adafruit-RGB-LCD-shield

Downloaded 'Eagle' to see the files.

Looks like my problem is the clone. RGB LCD demo works fine with an R3 UNO.

Thanks,
- Wally
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Re: Positive 16x2 RGB LCD not working, no backlight

by wallykissel on Mon Feb 04, 2013 11:46 am

Found the problem with the I2C communication. Followed the A4 & A5 lines on the LCD shield and the Due many times but never looked back at the ATMega pins. Mystery solved, all is well. (It actually was more like a solder 'splash' as it came loose very easily. None the less, it was shorting the pins.)
Attachments
solder.jpg
Solder bridge on ATMega pins
solder.jpg (79.13 KiB) Viewed 425 times
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Re: Positive 16x2 RGB LCD not working, no backlight

by adafruit_support_bill on Mon Feb 04, 2013 11:49 am

Good diagnostic work! Thanks for the follow-up.
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