接线：GND 5V D14 D15

 1 #include <Wire.h> 
 2 #include <LiquidCrystal_I2C.h>
 3 
 4 LiquidCrystal_I2C lcd(0x3F,16,2);  // 设置液晶地址 0x27  设置一行显示的字符 16个 2 行显示
 5 
 6 void setup()
 7 {
 8   lcd.init();                      //初始化
 9  
10   // Print a message to the LCD.
11   lcd.backlight();   //打开背光
12   lcd.print("Hello, world!");  //输出内容
13 }
14 
15 void loop()
16 {
17 }

注意，液晶地址可能不同，无法点亮

地址查询

 1 #include <Wire.h>
 2 
 3 
 4 void setup()
 5 {
 6 Wire.begin();
 7 
 8 Serial.begin(9600);
 9 Serial.println("\nI2C Scanner");
10 }
11 
12 
13 void loop()
14 {
15 byte error, address;
16 int nDevices;
17 
18 Serial.println("Scanning...");
19 
20 nDevices = 0;
21 for(address = 1; address < 127; address++ )
22 {
23 // The i2c_scanner uses the return value of
24 // the Write.endTransmisstion to see if
25 // a device did acknowledge to the address.
26 Wire.beginTransmission(address);
27 error = Wire.endTransmission();
28 
29 if (error == 0)
30 {
31 Serial.print("I2C device found at address 0x");
32 if (address<16)
33 Serial.print("0");
34 Serial.print(address,HEX);
35 Serial.println(" !");
36 
37 nDevices++;
38 }
39 else if (error==4)
40 {
41 Serial.print("Unknow error at address 0x");
42 if (address<16)
43 Serial.print("0");
44 Serial.println(address,HEX);
45 }
46 }
47 if (nDevices == 0)
48 Serial.println("No I2C devices found\n");
49 else
50 Serial.println("done\n");
51 
52 delay(5000); // wait 5 seconds for next scan
53 }