Arduino 项目笔记 |基于 Arduino 和 IoT 云平台搭建物联网系统（附MIT APP Inventor手机客户端）

参考资料：

首先 ，构建这个项目我们需要：

• arduino物联网模块（ESP8266WIFI芯片）
• 非接触式水位检测传感器
• Thing Speak IOT平台免费账户
• IFTTT 账户

该项目的设计理念是在饮水机与水桶的结合处设置传感器，传感器监测饮水桶中的水量变化并上传数据给水厂商；当水位达到设定的阈值时，发送用户信息（地址、电话等等）给水厂商，并规划配送水路线规划。为用户省去了打电话订水这一繁琐的步骤。

方案一：基于ESP8266 WiFi芯片物联网模块设计，其中运用Thing Speak IOT免费平台采集数据，IFTTT 事件触发发送邮件到手机端。

第一步、基于ESP8266WIFI 物联网开发板模块购买指南。

• Arduino物联网开发板 ESP8266 WIFI芯片非模块 OLED 可刷NodeMCU（附：此开发板 “Heltec 惠特自动化开发板”技术文档GitHub中详细介绍了开发环境配置、开发板管理、库文件下载等等）
• ESP8266 物联网开发模块 适用于 Arduino 编译器 物联网套件CH-3

第二步、Arduino IDE 基于Node MCU开发环境搭建。在开发板管理器中搜索 “ esp8266 ” 会出现相应的开发板信息。

注意：这一步的时候可能会出现 “下载平台索引失败 ” ！！！

解决方案：

arduino 下载 https://downloads.arduino.cc/packages/package_index.json error 出错的解决方法

第三步、Arduino IDE 基于Node MCU库文件配置。在库管理器中 搜索 “ ThingSpeak ” ,下载安装第一个库。

第四步、程序测试。选择示例ThingSpeak 中的示例程序。

关键代码：主要是修改WiFi账号、密码以及ThinkSpeak 的频道ID、**（后面介绍）

char ssid[] = "DengHongji";   // your network SSID (name) WIFI账号//
char pass[] = "denghongji123";   // your network password WIFI密码//
int keyIndex = 0;            // your network key Index number (needed only for WEP)
WiFiClient  client;

unsigned long myChannelNumber = 864372;//ThingSpeak 频道号码//
const char * myWriteAPIKey = "T6KJBZ0LLRV29SN1";//ThingSpeak Write API Key **//

完整代码如下：

/*
  WriteSingleField
  
  Description: Writes a value to a channel on ThingSpeak every 20 seconds.
  
  Hardware: ESP8266 based boards
  
  !!! IMPORTANT - Modify the secrets.h file for this project with your network connection and ThingSpeak channel details. !!!
  
  Note:
  - Requires ESP8266WiFi library and ESP8622 board add-on. See https://github.com/esp8266/Arduino for details.
  - Select the target hardware from the Tools->Board menu
  - This example is written for a network using WPA encryption. For WEP or WPA, change the WiFi.begin() call accordingly.
  
  ThingSpeak ( https://www.thingspeak.com ) is an analytic IoT platform service that allows you to aggregate, visualize, and 
  analyze live data streams in the cloud. Visit https://www.thingspeak.com to sign up for a free account and create a channel.  
  
  Documentation for the ThingSpeak Communication Library for Arduino is in the README.md folder where the library was installed.
  See https://www.mathworks.com/help/thingspeak/index.html for the full ThingSpeak documentation.
  
  For licensing information, see the accompanying license file.
  
  Copyright 2018, The MathWorks, Inc.
*/

#include "ThingSpeak.h"
#include "secrets.h"
#include <ESP8266WiFi.h>

//char ssid[] = "CMCC-R6Qs";   // your network SSID (name) WIFI账号//
//char pass[] = "qmt2fx3q";   // your network password WIFI密码//

char ssid[] = "DengHongji";   // your network SSID (name) WIFI账号//
char pass[] = "denghongji123";   // your network password WIFI密码//
int keyIndex = 0;            // your network key Index number (needed only for WEP)
WiFiClient  client;

unsigned long myChannelNumber = 864372;//ThingSpeak 频道号码//
const char * myWriteAPIKey = "T6KJBZ0LLRV29SN1";//ThingSpeak Write API Key **//

int number = 20;

void setup() {
  Serial.begin(9600);  // Initialize serial

  WiFi.mode(WIFI_STA); 
  ThingSpeak.begin(client);  // Initialize ThingSpeak
}

void loop() {

  // Connect or reconnect to WiFi
  
  if(WiFi.status() != WL_CONNECTED){
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(SECRET_SSID);
    delay(1000);  
    while(WiFi.status() != WL_CONNECTED){
      WiFi.begin(ssid, pass);  // Connect to WPA/WPA2 network. Change this line if using open or WEP network
      Serial.print(".");
      delay(5000);     
    } 
    Serial.println("\nConnected.");
  }
  
  // Write to ThingSpeak. There are up to 8 fields in a channel, allowing you to store up to 8 different
  // pieces of information in a channel.  Here, we write to field 1.
  int x = ThingSpeak.writeField(myChannelNumber, 1, number, myWriteAPIKey);
  if(x == 200){
    Serial.println("Channel update successful.");
  }
  else{
    Serial.println("Problem updating channel. HTTP error code " + String(x));
  }

  // change the value
  number--;
  if(number < 10){
    
    ThingSpeak.writeField(myChannelNumber, 2, "Warning~~~", myWriteAPIKey);
    
    if(number < 1){
      
    number = 20;
  }
  }
  
  delay(1000); // Wait 20 seconds to update the channel again
}

第五步、关于ThingSpeak IOT平台以及IFTTT平台的应用。
参考文章/视频：

• 【什么是IFTTT？】IFTTT自訂觸發條件，當發生A，則做B，讓網路自動幫你作事 - YouTube
• 【ThingSpeak with Arduino】How to Use ThingSpeak with Arduino - YouTube
• 【ESP8266+ThingSpeak+IFTTT】Tutorial #4 ESP8266 - Integración de IFTTT con ThingSpeak - YouTube
• 文章：使用ESP8266和Arduino的基于物联网的患者监护系统

方案二： 此方案的优点在于软/硬件设计简单且能实现作品的部分功能。所需材料如下：

• Arduino nano
• 水位检测电路
• 蓝牙CH-06
• 手机APP（MIT APP Inventor）

参考代码如下：当感应探头侦测到水桶中没有水的时候，蓝牙 函数 BT.print(1) 发送 信号给手机APP

/*
arduino数字口引脚与蓝牙引脚连接：
RX（接收）---------------9（发送）
TX(发送)---------------- 8（接收）
*/
 
#include <SoftwareSerial.h>
//使用软件串口，能讲数字口模拟成串口
SoftwareSerial BT(8, 9);  //新建对象，接收脚为8，发送脚为9
char val;  //存储接收的变量

#define  READ_PIN   13

 int var = 1;
 int var0 = 0;
 
void setup() {
  Serial.begin(9600); //与电脑的串口连接
  pinMode(READ_PIN,INPUT);
  Serial.println("BT is ready!");
  BT.begin(9600);  //设置波特率
  
  
}
 
void loop() {
  
  /*
  //如果串口接收到数据，就输出到蓝牙串口
  if (Serial.available()) {
    val = Serial.read();
    BT.print(val);
  }
 
  //如果接收到蓝牙模块的数据，输出到屏幕
  if (BT.available()) {
    val = BT.read();
    Serial.print(val);
  }*/
  
  
  /*
 if (BT.available()) {
    val = BT.read();
    
    if(val == '1')
    {
      digitalWrite(led,HIGH);
    }
    if(val == '0')
    {
      digitalWrite(led,LOW);
    }
    
    Serial.print("massage is:");
    Serial.println(val);
  }*/
   
    
    Serial.println(digitalRead(READ_PIN));

    if(digitalRead(READ_PIN) == 1)

  { 
    BT.print(1);  

    Serial.println("Send  successful1!");
    
    }
 
   
   
   delay(500);

 
  
 
 
 
}