# Adafruit Char LCD not working

I use a normal 2x16 LCD display and it already shows the black boxes along the upper row. But Adafruit_CharLCD is not working. I installed it with pip and I can import it into my Python script and use its functions without any errors, but nothing happens. I checked all connections several times and even changed the GPIO Pins used for the D4 - D7 inputs and retried it. Just nothing, there are still the black boxes. I am using a Pi 3 B and this is the script I use:

#!/usr/bin/python
import time

# Raspberry Pi pin configuration:
lcd_rs        = 27  # Note this might need to be changed to 21 for older revision Pi's.
lcd_en        = 22
lcd_d4        = 25
lcd_d5        = 24
lcd_d6        = 23
lcd_d7        = 18
lcd_backlight = 4

# Define LCD column and row size for 16x2 LCD.
lcd_columns = 16
lcd_rows    = 2

# Alternatively specify a 20x4 LCD.
# lcd_columns = 20
# lcd_rows    = 4

# Initialize the LCD using the pins above.
lcd = LCD.Adafruit_CharLCD(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7,
lcd_columns, lcd_rows, lcd_backlight)

# Print a two line message
lcd.message('Hello\nworld!')


Any ideas, what I missed? Thanks for answers!

• Does your screen have a pot (it may just be that your contrast is incorrect)? – Steve Robillard Jan 6 '18 at 18:53
• Uhm yes, I found the pot and connected it (didn't use it before, thanks) but unfortunately doesn't help. When I close it, the black boxes get invisible, but still no text shown – mep Jan 6 '18 at 19:28
• There's a shed load of videos on YT for this: youtube.com/results?search_query=adafruit+charlcd – Dougie Jan 13 at 22:28