### 5.12 APP-gesteuerte Smart Farm

**Achtung: Lassen Sie bei Experimenten kein Wasser aus den Plastikbecken überlaufen. Das Verschütten von Wasser auf andere Sensoren kann einen Kurzschluss verursachen oder Module außer Betrieb setzen. Wenn Batterien nass werden, kann es sogar zu einer Explosion kommen. Seien Sie besonders vorsichtig! Jüngere Benutzer sollten dies unter Aufsicht ihrer Eltern bedienen. Verwenden Sie Batterien zur Stromversorgung anstelle von nur USB.**

Öffnen Sie den Code **5.12.1APP-Smart-Farm** mit der Arduino IDE.

```c
#include <Arduino.h>
#ifdef ESP32
#include <WiFi.h>
#elif defined(ESP8266)
#include <ESP8266WiFi.h>
#endif

#include <dht11.h>
#include <ESP32Servo.h>
#include <LiquidCrystal_I2C.h>

//To be displayed
#define DHT11PIN 17         //Temperature and humidity sensor pin
#define RAINWATERPIN 35     //Steam sensor pin
#define LIGHTPIN 34         //Photoresistor pin
#define WATERLEVELPIN 33    //Water level sensor pin
#define SOILHUMIDITYPIN 32  //Soil humidity sensor pin
//To be controlled
#define LEDPIN 27     //LED pin
#define RELAYPIN 25   //Relay pin (to control water pump)
#define SERVOPIN 26   //Servo pin
#define FANPIN1 19    //Fan IN+ pin
#define FANPIN2 18    //Fan IN- pin
#define BUZZERPIN 16  //Buzzer pin

const char* ssid = "your_SSID";
const char* pwd = "your_PASSWORD";

//Initialize LCD1602, 0x27 is I2C address
LiquidCrystal_I2C lcd(0x27, 16, 2);
WiFiServer server(80);  //Initialize wifi server
dht11 DHT11;            //Initialize temperature and humidity sensor
Servo myservo;          // create servo object to control a servo
                        // 16 servo objects can be created on the ESP32

//Define variable as detected values
String request;
String dataBuffer;
int Temperature;   //Temperature
int Humidity;      //Humidity
int SoilHumidity;  //Soil humidity
int Light;         //Brightness
int WaterLevel;    //Water level
int Rainwater;     //Rainfall

void setup() {
  Serial.begin(9600);
  //Connect to wifi
  WiFi.begin(ssid, pwd);
  //Determine whether connected
  Serial.println("Connecting to WiFi...");
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  delay(1000);
  //Serial monitor prints wifi name and IP address
  Serial.println("Connected to WiFi");
  Serial.print("WiFi NAME:");
  Serial.println(ssid);
  Serial.print("IP:");
  Serial.println(WiFi.localIP());

  //Initialize LCD
  lcd.init();
  // Turn the (optional) backlight off/on
  lcd.backlight();
  //lcd.noBacklight();
  lcd.clear();
  //Set the position of cursor
  lcd.setCursor(0, 0);
  //LCD prints
  lcd.print("IP:");
  //Set the position of cursor
  lcd.setCursor(0, 1);
  //LCD prints
  lcd.print(WiFi.localIP());

  //set pins mode
  pinMode(LEDPIN, OUTPUT);
  pinMode(RAINWATERPIN, INPUT);
  pinMode(LIGHTPIN, INPUT);
  pinMode(SOILHUMIDITYPIN, INPUT);
  pinMode(WATERLEVELPIN, INPUT);
  pinMode(RELAYPIN, OUTPUT);
  pinMode(FANPIN1, OUTPUT);
  pinMode(FANPIN2, OUTPUT);
  pinMode(BUZZERPIN, OUTPUT);
  delay(1000);

  // attaches the servo on pin 26 to the servo object
  myservo.attach(SERVOPIN);
  myservo.write(160);

  //Start server
  server.begin();

  // Configure LEDC channel
  ledcAttachChannel(BUZZERPIN, 1000, 8, 4);
}

void loop() {
  //Check whether a client is connected to the web server
  //When the client is connected to server, "server.available()" returns a WiFiClient object for communication at client-side.
  WiFiClient client = server.available();
  if (client) {
    Serial.println("New client connected");
    while (client.connected()) {
      //Determine whether the server sends data
      if (client.available()) {
        request = client.readStringUntil('s');
        Serial.print("Received message: ");
        Serial.println(request);
      }
      //Acquire all senser data
      getSensorsData();
      //put all data into "dataBuffer"
      dataBuffer = "";
      dataBuffer += String(Temperature, HEX);
      dataBuffer += String(Humidity, HEX);
      dataBuffer += dataHandle(SoilHumidity);
      dataBuffer += dataHandle(Light);
      dataBuffer += dataHandle(WaterLevel);
      dataBuffer += dataHandle(Rainwater);
      //Send data to server, transmit to APP
      client.print(dataBuffer);
      delay(500);

      //LED
      if (request == "a") {
        digitalWrite(LEDPIN, HIGH);
      } else if (request == "A") {
        digitalWrite(LEDPIN, LOW);
      }
      //Irrigation
      else if (request == "b") {
        digitalWrite(RELAYPIN, HIGH);
        delay(400);  //Irrigation delay
        digitalWrite(RELAYPIN, LOW);
        delay(650);
      }
      //Fan
      else if (request == "c") {
        delay(800);
        digitalWrite(FANPIN1, HIGH);
        digitalWrite(FANPIN2, LOW);
        delay(200);
      } else if (request == "C") {
        digitalWrite(FANPIN1, LOW);
        digitalWrite(FANPIN2, LOW);
      }
      //Feeding box
      else if (request == "d") {
        //Servo rotates to 80°, open feeding box
        myservo.write(80);
        delay(500);
      } else if (request == "D") {
        //Servo rotates to 160°, close feeding box
        myservo.write(160);
      }
      //Buzzer
      else if (request == "e") {
        ledcWriteTone(BUZZERPIN, 262);
        delay(800);
        ledcWriteTone(BUZZERPIN, 0);
        delay(100);
      }
      request = "";
    }
    Serial.println("Client disconnected");
  }
}

void getSensorsData() {
  //Acquire data
  int chk = DHT11.read(DHT11PIN);
  //Steam sensor
  Rainwater = analogRead(RAINWATERPIN);
  //Photoresistor
  Light = analogRead(LIGHTPIN);
  //Soil humidity sensor
  SoilHumidity = analogRead(SOILHUMIDITYPIN) * 1.8;
  //Water level sensor
  WaterLevel = analogRead(WATERLEVELPIN) * 1.8;
  //Temperature
  Temperature = DHT11.temperature;
  //Humidity
  Humidity = DHT11.humidity;
}


//Convert data into percentage
String dataHandle(int data) {
  // Convert analog values into percentage
  int percentage = (data / 4095.0) * 100;
  // If the converted percentage is greater than 100, output 100.
  percentage = percentage > 100 ? 100 : percentage;
  // Six characters store hexadecimal strings, one character is as terminators
  char hexString[3];
  // Convert hexadecimal values to 6-digit hexadecimal strings, add leading zeros: 0 is 00, 1 is 01...
  sprintf(hexString, "%02X", percentage);

  return hexString;
}
```

Ändern Sie `your_SSID` im Code in den Namen Ihres WLANs und `your_PASSWORD` in das WLAN-Passwort. Laden Sie dann den Code hoch.

```c
const char* ssid = "your_SSID";
const