}

int backlightState = LOW;

long previousMillis = 0;

long interval = 1000;

void loop(){

unsigned long currentMillis = millis();

if(currentMillis - previousMillis > interval) {

previousMillis = currentMillis;

if (backlightState == LOW)

backlightState = HIGH;

else

backlightState = LOW;

if(backlightState == HIGH)

lcd.backlight();

else lcd.noBacklight();

}

}

If you want to use the library's own sample code, pay attention to modify the initialization

statement, need to change:

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

display

to:

LiquidCrystal_I2C lcd(0x20,16,2); // set the LCD address to 0x20 for a 16 chars and 2 line

display(All jumpers should be connected!)

Because the default initialization statement is for LCD1602!

 

 

 

    https://www.dfrobot.com/wiki/index.php/I2C/TWI_LCD1602_Module_(Gadgeteer_Compatible)_(SKU:_DFR0063)8‐10‐18