Adafruit i2c 16x2 RGB LCD Pi Plate issues

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dmkanter
 
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Joined: Tue Apr 07, 2015 4:38 pm

Adafruit i2c 16x2 RGB LCD Pi Plate issues

Post by dmkanter »

I did all the soldering and hooked it up to the pi. When try to boot with the LCD plate plugged in, the pi never boots.
When I take out the pi boots.
I also installed all the programs and libs mentioned and it fails the tests.
here are my pictures (Front and and back, and on the pi1)

Front:
Image

Back:
Image

the output from i2cdetect -y 1:

Code: Select all

pi@raspberrypi ~ $ sudo i2cdetect -y 1 
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
I also tried to run /char_lcd_plate.py after cloning from github and installing the python libs.

Code: Select all

pi@raspberrypi ~/Adafruit_Python_CharLCD/examples $ sudo ./char_lcd_plate.py 
Traceback (most recent call last):
  File "./char_lcd_plate.py", line 10, in <module>
    lcd = LCD.Adafruit_CharLCDPlate()
  File "build/bdist.linux-armv6l/egg/Adafruit_CharLCD/Adafruit_CharLCD.py", line 432, in __init__
  File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/MCP230xx.py", line 154, in __init__
  File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/MCP230xx.py", line 50, in __init__
  File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/MCP230xx.py", line 134, in write_iodir
  File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/I2C.py", line 122, in writeList
IOError: [Errno 5] Input/output error



help appreciated!

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adafruit_support_rick
 
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Joined: Tue Mar 15, 2011 11:42 am

Re: Adafruit i2c 16x2 RGB LCD Pi Plate issues

Post by adafruit_support_rick »

Unfortunately, you've soldered the MCP23017 chip in backwards. The semicircular indent on the chip package should match the indent on the silkscreen.

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dmkanter
 
Posts: 21
Joined: Tue Apr 07, 2015 4:38 pm

Re: Adafruit i2c 16x2 RGB LCD Pi Plate issues

Post by dmkanter »

yikes! hope I haven't done any damage. I'll try to reverse it tonight.

Also, if I wanted to manually hook up the pins on the MCP23017 to my arduino according to the tutorial you have on this site, would that work? I mean I do understand I purchased the shield for a rasberry pi, but if I directly use a breadboard or connect the wires like it describes in the adafruit tutorial, that should work, right?

Thanks,
David

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adafruit_support_rick
 
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Joined: Tue Mar 15, 2011 11:42 am

Re: Adafruit i2c 16x2 RGB LCD Pi Plate issues

Post by adafruit_support_rick »

Yes, you can hook it up to an Arduino. 5V, GND, SCL and SDA.

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dmkanter
 
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Joined: Tue Apr 07, 2015 4:38 pm

Re: Adafruit i2c 16x2 RGB LCD Pi Plate issues

Post by dmkanter »

I could not desolder the MCP23017 the other direction, so instead I tried to go through this tutorial to wire it up manually using pins 1-16 and a breadboard + arduino.
https://learn.adafruit.com/character-lc ... racter-lcd (I couldn't get the top LCD shield off either, so I had to solder the connections with copper wire into a breadboard).

i can get the lcd to glow with the backlight and the potentiometer seems to work, but I can't get it to display hello world.
I've tried with and without a resistor. I am wondering if there are pins I'm not using they need to be grounded perhaps?


Image

Image

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adafruit_support_mike
 
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Re: Adafruit i2c 16x2 RGB LCD Pi Plate issues

Post by adafruit_support_mike »

You need to remove the old chip. It has input protection circuits that can interfere with the signals on those traces.

If desoldering doesn't work, you can clip the leads with a pair of flush cutters, then remove what's left of them one hole at a time.

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dmkanter
 
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Re: Adafruit i2c 16x2 RGB LCD Pi Plate issues

Post by dmkanter »

Ok. Will try the flush cutters... Wonder if it's time to invest in a desoldering iron too..

The pump and wick aren't really working out for me.

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Bel_Z_Bub
 
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Re: Adafruit i2c 16x2 RGB LCD Pi Plate issues

Post by Bel_Z_Bub »

tip: when you have cut the chip of the board, put the plate in an upright position, in e.g a clamp, so you can heat a pin from one side of a pin hole with your soldering iron and use the pump (or maybe some tweezers first to pull the leftover pin out), on the other side of the hole. this way you will get the holes almost as if they were new.

Then just order a new chip and solder it in the right way.

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