引脚说明
GND ------ 地线
VCC ------ 电源（5V ）
SDA ------ I2C 数据线
SCL ------ I2C 时钟线
接线方法
LCD1602 i2c模块 Ardunio Uno
GND -------------------GND接地线
VCC---------------------5V 接电源
SDA-------------------- A4
SCL--------------------- A5
程序实现
#include <LiquidCrystal_I2C.h> //引用I2C库 LiquidCrystal_I2C lcd(0x27, 16, 2);//I2C设备地址、列数，行数unsigned long starttime;//计时开始时刻unsigned long stoptime;//计时终止时刻unsigned long looptime;//计时长度unsigned char k=0;//光标初始位置unsigned char Nowhour=12;//小时调整unsigned char Nowminute=13;//分钟调整void setup() { // put your setup code here, to run once: lcd.init(); // 初始化LCD lcd.backlight(); //设置LCD背景灯亮 starttime = millis();//上电计时开始（毫秒）}void loop() { // put your main code here, to run repeatedly: unsigned char Second, Hsecond, Lsecond, Minute, Hminute, Lminute, Hour, Hhour, Lhour; stoptime = millis(); looptime = stoptime - starttime; Second = (looptime / 1000) % 60;//计算秒 Hsecond = Second / 10;//秒的十位 Lsecond = Second % 10;//秒的个位 Minute = (Nowminute+(looptime / 1000) / 60) % 60; Hminute = Minute / 10;//分钟的十位 Lminute =Minute % 10;//分钟的个位 Hour = (Nowhour+(looptime / 1000) / 3600) % 24; Hhour = Hour / 10;//小时的十位 Lhour = Hour% 10;//小时的个位 Lcd_XianShi(k%16, 0, Hhour);//显示小时的十位 Lcd_XianShi((k+1)%16, 0, Lhour);//显示小时的个位 Lcd_XianShi((k+3)%16, 0, Hminute);//显示分钟的十位 Lcd_XianShi((k+4)%16, 0, Lminute);//显示分钟的个位 Lcd_XianShi((k+6)%16, 0, Hsecond);//显示秒的十位 Lcd_XianShi((k+7)%16, 0, Lsecond);//显示秒的个位 if (Second % 2 == 1)//显示冒号 { lcd.setCursor((k+2)%16, 0); lcd.print(":"); lcd.setCursor((k+5)%16, 0); lcd.print(":"); } if (Second % 2 == 0)//不显示冒号 { lcd.setCursor((k+2)%16, 0); lcd.print(" "); lcd.setCursor((k+5)%16, 0); lcd.print(" "); }}void Lcd_XianShi(unsigned char a, unsigned char b, unsigned char c){ lcd.setCursor(a, b); //设置显示光标位置 lcd.print(c); }