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LCD I2C display not working with Adafruit Metro M4 express
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Please be positive and constructive with your questions and comments.

LCD I2C display not working with Adafruit Metro M4 express

by Sam_ on Wed Aug 12, 2020 5:45 pm

I've an LCD I2C display which is working perfectly fine with an arduino Uno and the liquidcrystal_i2c library.

But when I connect the screen to the Adafruit Metro M4 express airlift (wifi) it lights up but only show squares. I've also tried the adafruit liquidcrystal library with no luck.


Connections:
I2C Character LCD <=> Adafruit/Arduino
GND <=> GND
VCC <=> 5 V
SDA <=> A4
SCL <=> A5


Code: Select all | TOGGLE FULL SIZE
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,20,4);  // set the LCD address to 0x27 for a 16 chars and 2 line display

void setup()
{
  lcd.init();                      // initialize the lcd
  // Print a message to the LCD.
  lcd.backlight();
  lcd.setCursor(3,0);
  lcd.print("Hello, world!");
  lcd.setCursor(2,1);
  lcd.print("Ywrobot Arduino!");
   lcd.setCursor(0,2);
  lcd.print("Arduino LCM IIC 2004");
   lcd.setCursor(2,3);
  lcd.print("Power By Ec-yuan!");
}


void loop()
{
}

Sam_
 
Posts: 1
Joined: Wed Aug 12, 2020 5:36 pm

Re: LCD I2C display not working with Adafruit Metro M4 expr

by dastels on Wed Aug 12, 2020 8:39 pm

It could be a signal level issue. You're powering the display with 5v, but the I2C signals are 3.3v. Can your display be powered with 3.3v? If not, you can use an I2C level shifter to shift them to 5v that the display can use. See https://www.adafruit.com/product/757.

Dave

dastels
 
Posts: 3531
Joined: Tue Oct 20, 2015 3:22 pm

Please be positive and constructive with your questions and comments.