Display

The reason for these contradicting addresses are the way Arduino interprets I2C addresses. By default, I2C use 7-bit addresses, but Arduino converts that to an 8-bit value by shifting the bits one position to the left. So, the SSD1306 datasheet says that the slave address is a 7-bit code that can be either 0x3C (0011-1100) or 0x3D (0011-1101), based on the SAO bit (set to hardware jumper). For Arduino:

0x3C (0011-1100) is shifted 1 bit right, and becomes 0x78 (0111-100)

0x3D (0011-1101) is shifted 1 bit right, and becomes 0x7A (0111-1010)

https://www.letscontrolit.com/forum/viewtopic.php?p=22817#p22818

Sample code:

https://drive.google.com/file/d/1Lri36HntSCUaWyiFp8AQp7NFcezpNYh_/view

16X2 1602 I2C/TWI LCD Display

https://www.keyestudio.com/free-shipping-keyestudio-16x2-1602-i2c-twi-lcd-display-module-for-arduino-uno-r3-mega-2560-white-in-blue-p0422-p0422.html

Introduction

This is great LCD display compatible with arduino. With limited pin resources, your project will quicly run out of resources using normal LCDs. With this I2C interface LCD module, you only need 2 lines (I2C)to display the information.If you already have I2C devices in your project, this LCD module actually cost no more resources at all. The adress can be set 0x27.

Specification

I2C Address:0x27
Back lit (Blue with white char color)
Supply voltage: 5V
Interface:I2C/TWI x1,Gadgeteer interface x2
Adjustable contrast

Sample code:

#include

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

void setup()

{

lcd.init(); // initialize the lcd

lcd.init();

// Print a message to the LCD.

lcd.backlight();

lcd.setCursor(3,0);

lcd.print("Hello, world!");

lcd.setCursor(2,1);

lcd.print("keyestudip!");

}

void loop()

{

}