Blink 5mm LED on the LCD Shield

blink_LCD.ino

// include the library code:
#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(13, 12, 10, 9, 8, 7);
// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(11, OUTPUT);
  lcd.begin(16, 2);
  // initialize the serial communications:
  Serial.begin(9600);
  lcd.write("LED Flashing!");
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(11, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(11, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second
}