analogBlink&1602IIC.ino

/*
  Blink

  Turns an LED on for one second, then off for one second, repeatedly.

  Most Arduinos have an on-board LED you can control. On the UNO, MEGA and ZERO
  it is attached to digital pin 13, on MKR1000 on pin 6. LED_BUILTIN is set to
  the correct LED pin independent of which board is used.
  If you want to know what pin the on-board LED is connected to on your Arduino
  model, check the Technical Specs of your board at:
  https://www.arduino.cc/en/Main/Products

  modified 8 May 2014
  by Scott Fitzgerald
  modified 2 Sep 2016
  by Arturo Guadalupi
  modified 8 Sep 2016
  by Colby Newman

  This example code is in the public domain.

  http://www.arduino.cc/en/Tutorial/Blink
*/
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
int serialPort = 5;
int brightness = 10;
boolean plus = true;



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

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  //pinMode(LED_BUILTIN, OUTPUT);
  pinMode(serialPort, OUTPUT);
  //Serial.begin(9600);


  lcd.init();                      // initialize the lcd 
 
  // Print a message to the LCD.
  lcd.backlight();
  lcd.print("Hello, world!");
}

// the loop function runs over and over again forever
void loop() {
  if(plus == true) {
    brightness+=5;
  }else if (plus == false){
    brightness-=5;
  }
  //Serial.println(brightness);
  lcd.print(brightness);
  lcd.print("   ");
  
  if(brightness == 5) {
    plus = true;
    analogWrite(serialPort, 0);
    delay(2500);
    lcd.backlight();
  }else if (brightness == 255) {
    plus = false;  
    delay(2500);
    lcd.noBacklight();
  }
  analogWrite(serialPort, brightness);

  delay(100);  
  //Serial.println(analogRead(A0));
}

analogBlink.ino

/*
  Blink

  Turns an LED on for one second, then off for one second, repeatedly.

  Most Arduinos have an on-board LED you can control. On the UNO, MEGA and ZERO
  it is attached to digital pin 13, on MKR1000 on pin 6. LED_BUILTIN is set to
  the correct LED pin independent of which board is used.
  If you want to know what pin the on-board LED is connected to on your Arduino
  model, check the Technical Specs of your board at:
  https://www.arduino.cc/en/Main/Products

  modified 8 May 2014
  by Scott Fitzgerald
  modified 2 Sep 2016
  by Arturo Guadalupi
  modified 8 Sep 2016
  by Colby Newman

  This example code is in the public domain.

  http://www.arduino.cc/en/Tutorial/Blink
*/

int serialPort = 5;
int brightness = 10;
boolean plus = true;

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  //pinMode(LED_BUILTIN, OUTPUT);
  pinMode(serialPort, OUTPUT);
  //Serial.begin(9600);
}

// the loop function runs over and over again forever
void loop() {
  if(plus == true) {
    brightness+=5;
  }else if (plus == false){
    brightness-=5;
  }
  //Serial.println(brightness);
  
  if(brightness == 5) {
    plus = true;
    analogWrite(serialPort, 0);
    delay(2500);
  }else if (brightness == 255) {
    plus = false;  
  }
  analogWrite(serialPort, brightness);
  delay(40);  
  //Serial.println(analogRead(A0));
}

IICAddressLookup.ino

/* 
将从机与arduino开发板通过IIC接口连接好。

SDA-->A4

SCK-->A5

上传以下代码至arudino，观察串口返回的结果。

Name:  IICaddressFound.ino 

Created: 2018/10/14 14:42:57 

Author: ipenn

*/

#include <Wire.h> //（将 IIC 所需的Wire.h头文件包含进来）

// the setup function runs once when you press reset or power the boardvoid setup() { 

Serial.begin(9600);//（开启串口，以接受结果） 

Wire.begin();//（初始化IIC连接，作为主机无需参数） 

for (int i = 0; i < 127; i++)//（IIC 地址从0~127(十进制)，一共128个遍历一遍就知道结果了） {  

Wire.beginTransmission(i);//（和地址i连接）  

int error = Wire.endTransmission();//（结束和地址i的连接，并接受返回值（只可能是0~4其中的一个值）。其中0表示成功）  

if (error == 0) {

//（如果返回值是0(成功)的话就返回地址，以十六进制）   

Serial.println();   

Serial.print("Device is found at : 0x");   

Serial.println(i,HEX);  

} 

}

}

// the loop function runs over and over again until power down or reset

void loop() {  }// loop 里什么都不干

arduino uno R3
输出口5 接电阻和小灯 然后接回输出口上的GND

Serial相关代码 指定波特率 把数据传回电脑