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Feather MO Express LCD only showing red and no text
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Feather MO Express LCD only showing red and no text

by xrave on Fri Apr 26, 2019 1:02 am

IMG_4644.png
IMG_4644.png (577.94 KiB) Viewed 136 times
I am running a Feather MO Express with an LCD 16x2 + and a backpack. I used the I2C Initialization and tried to put a message. My LCD only has a solid color of Red and no text. I have tried multiple examples and can't get anything but the red background color. After saving the text code the LED on my Feather MO Express blink Green, Yellow, and blue multiple times. The example code is listed below along with links to the lcd and backpack I have.

import board
import busio
import adafruit_character_lcd.character_lcd_i2c as character_lcd
i2c = busio.I2C(board.SCL, board.SDA)
cols = 16
rows = 2
lcd = character_lcd.Character_LCD_I2C(i2c, cols, rows)
lcd.message = "Hello\nCircuitPython"



LCD
https://www.adafruit.com/product/399

LCD Backpack
https://www.adafruit.com/product/292
Attachments
IMG_4645.png
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xrave
 
Posts: 13
Joined: Mon Apr 16, 2018 10:26 pm

Re: Feather MO Express LCD only showing red and no text

by adafruit_support_mike on Fri Apr 26, 2019 2:55 am

That's normal for the LCD Backpack: it only has one backlight-control pin, on LCD pin #16 (which controls the red LED).

LCD pins 17 and 18 control the green and blue LEDs, and those aren't connected to anything in the photo above.

You'll need to control pins #17 and #18 with wires connected to GPIO pins on the Feather.

adafruit_support_mike
 
Posts: 58856
Joined: Thu Feb 11, 2010 2:51 pm

Re: Feather MO Express LCD only showing red and no text

by xrave on Fri Apr 26, 2019 3:08 am

Shouldn't I be seeing text on the screen when I write a message such as lcd.message = "Hello\nCircuitPython"

xrave
 
Posts: 13
Joined: Mon Apr 16, 2018 10:26 pm

Re: Feather MO Express LCD only showing red and no text

by xrave on Fri Apr 26, 2019 4:47 am

So I figured out its the contrast up too high that is causing my inability to see. However after fixing that I am seeing that only a couple characters are showing even though I have the line below. The strange part is if I put the second line the entire thing shows. Got any suggestions?

lcd.message = "HelloCircuit"

lcd.message = "ccccccccccccccc"
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xrave
 
Posts: 13
Joined: Mon Apr 16, 2018 10:26 pm

Re: Feather MO Express LCD only showing red and no text

by adafruit_support_mike on Sat Apr 27, 2019 2:33 am

Post the code you’re using (between CODE tags please) and we’ll take a look.

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Joined: Thu Feb 11, 2010 2:51 pm

Please be positive and constructive with your questions and comments.