植物监测仪 · 光子开发板与土壤湿度传感器

本项目主要制作一款植物监测仪，功能是：水分传感器提示LED闪烁，并在植物需要用水时使用IFTTT向手机发送相关信息。

该项目需要使用的东西：

硬件

光子（Particle Photon）物联网开发板

Particle Electron

电容式土壤湿度传感器

软件

IFTTT Maker服务

ThingSpeak应用程序界面

故事

大部分人的房子里面都有一种或多种盆栽植物需要定期进行浇水。问题是，除非您是开专业花店的，否则您并不知道每棵植物何时需要浇水。为了解决这个问题，我们开发了一个系统，当您的植物需要水分时，系统会通过手机向您发送通知。

首先，水分传感器连接Photon并放置在盆栽植物中。然后，当传感器读取湿度值低于20时，Photon会通过编程方式发布一个名为“moisturePercentage”的事件。同时，Electron会订阅和发布该事件，以及发布自己的事件，两个事件被称为“plantStatus”和“handshake”；届时它将会把名为thirsty的变量的值从true更改为false。IFTTT将订阅“plantStatus”并向用户的IFTTT应用程序发送相关通知，而Photon将订阅“handshake”事件并在听到它时停止发布“moisturePercentage”。在electron的代码中，某个while循环将导致其LED开始闪烁，并对变量进行赋值thirsty = true。这为用户提供了另一种通知方式，防止用户未带手机的情况。当植物淹泡在水中时，水分含量将升至45以上，这导致Photon发布另一个名为“plantWatered”的事件，Electron会订阅该事件。这使得植物缺水的变量设置为false，防止电子LED闪烁。经过一段时间后，这些水分将被植物所吸收，并且整个过程将重新开始。

我们决定观察植物吸收水分时，水分含量如何变化，这个过程将非常有趣。因此，每次Photon对其进行记录时，我们都会通过一些事物对水含量进行记录。我们发现我们所选的血根草植物能够很快吸收我们供给的水，并且必须每隔一天至少浇一次水。

原理图

Particle Photon的代码：

[mw_shl_code=applescript,true]int boardLed = D7; //LED D7 for testing purposes
int moisture_pin = A1; //connection point for moisture sensor
bool messageSent = false; //variable for checking if notification has been sent to phone
String plantWatered = "Your plant has been watered and is moist";
void setup() {
pinMode(boardLed,OUTPUT); //output to turn on LED for setup
pinMode(moisture_pin,INPUT); //Input from moisture sensor

//Flashes LED to indicate that flash is successful.
digitalWrite(boardLed,HIGH);
delay(2000);
digitalWrite(boardLed,LOW);
delay(2000);
digitalWrite(boardLed,HIGH);
delay(2000);
digitalWrite(boardLed,LOW);
delay(2000);
}
void loop() {
//digitalWrite(boardLed,HIGH);
// Now we'll take some readings...
int moisture_analog = analogRead(moisture_pin); // read capacitive sensor
float moisture_percentage = (100 - ((moisture_analog/4095.00) * 100 ));
Particle.subscribe("handshake", handShake, "34002f000a47373336373936"); //Subscribe command to listen to other device
if (moisture_percentage <= 22 && messageSent == false){ //Checks if moisture percentage is below threshold and also checks if the water message has been sent
   Particle.publish("moisturePercentage", String(moisture_percentage),60,PUBLIC); //Publishes for message to be sent
}
if (moisture_percentage > 40 && messageSent == true){ //Checks if moisture levels have gone back up and also checks if message has been sent
      Particle.publish("plantWatered", plantWatered, 60, PUBLIC);
      messageSent = false; //If message sent, and plant watered, it resets the program so that the function above will run
}

Particle.publish("plantStatus_percentage", String(moisture_percentage),60,PUBLIC); //Publish command for logging data and sending it to thingspeak
//digitalWrite(boardLed,LOW);
delay(15000);
}
void handShake( const char *event, const char *data){ //If the message has been sent, it sets messageSent to true
messageSent = true;
}[/mw_shl_code]

Particle Electron 的代码：

[mw_shl_code=applescript,true]int led=D7;//led that indicates the plant needs water
bool sent=false;// has the notification to water the plant been sent
bool thirsty=false;//whether or not the plant needs water
void setup()
{
  pinMode(led,OUTPUT);
}
void loop()
{
   Particle.subscribe("moisturePercentage",waterPlant,"3c0026001747373335333438");
while(thirsty==true)
{//while the plant needs water the LED flashes and the electron listens for when the water level goes up
digitalWrite(led,HIGH);
delay(500);
digitalWrite(led,LOW);
delay(500);
Particle.subscribe("plantWatered",breakloop,"3c0026001747373335333438");// checks for when the plant has been waterd.
}
delay(5000);// this loop every five minutes
}
void waterPlant( const char *event, const char*data)
{
      Particle.publish("plantStatus","thirsty",60,PUBLIC);//sends a message to IFTTT to notify me to water my plants.
      sent=true;
      Particle.publish("handshake","sent",60,PUBLIC);// notifies the photon that the message has been sent
      thirsty=true;
}
void breakloop( const char *event, const char*data)// changes thirsty to false to break the while loop and stop the led from flashing
{
      thirsty=false;
      sent=false;
   }
[/mw_shl_code]

原文：How to make a Plant Monitor

植物监测

如何制作植物监测仪