LCD1602 on pins 7 to 12, on an Arduino Uno

// A 16x2 LCD on pins 7 to 12: a greeting, and a seconds counter under it.
//
//   LCD RS -> pin 7    LCD E  -> pin 8
//   LCD D4 -> pin 9    LCD D5 -> pin 10   LCD D6 -> pin 11   LCD D7 -> pin 12
//   LCD RW, VSS, K -> GND     LCD VDD, A -> 5V
//   LCD V0 (contrast) -> GND here; on the bench, the middle leg of a 10k pot
//
// The display has its own controller chip. LiquidCrystal sends it commands
// and characters four bits at a time over D4 to D7, and E tells it when the
// four bits are ready. The order of the numbers in the constructor is RS, E,
// D4, D5, D6, D7.
//
// lcd.setCursor(column, row) counts from zero: (0, 1) is the start of the
// second line.

#include <LiquidCrystal.h>

LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void setup() {
  lcd.begin(16, 2);
  lcd.print("Hello, World!");
  Serial.begin(9600);
  Serial.println("Mokxi Uno: LCD1602 on pins 7 to 12");
}

void loop() {
  lcd.setCursor(0, 1);
  lcd.print(millis() / 1000);
  lcd.print(" s");
  delay(200);
}