Keyestudio EASY PLUG Ultimate Starter Kit Manual page 59

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For example:
Separately connect the SDA (A4) and SCL (A5) of Arduino Uno to SDA and SCL pins of IIC LCD1602,
then set the address of your LCD1602 screen, the LCD address we used here is 0x27.
Then upload the code, LCD screen has two lines, you should see the line 1 print HELLO, and line 2 print
123456789.