เกี่ยวกับโค้ดArduino+database

ต้องการให้Arduinoส่งค่าไปยัง database แล้วอ่านค่าที่ database
Code Arduino Mega
[Spoil] คลิกเพื่อดูข้อความที่ซ่อนไว้
#include <Dhcp.h>
#include <Dns.h>
#include <SPI.h>
#include <Ethernet.h>
#include <EthernetClient.h>
#include <EthernetServer.h>
#include <EthernetUdp.h>
#include <SoftwareSerial.h>
IPAddress ip(192, 168, 0, 177);
EthernetClient client;
EthernetServer server(80);
byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
//byte server[] = { 107,180,41,159 };
volatile int NbTopsFan;
int Calc=0;                              
int hallsensor = 2;
volatile int NbTopsFan0;
int Calc0=0;                              
int hallsensor0 = 3;
volatile int NbTopsFan1;
int Calc1=0;                              
int hallsensor1 = 4;
volatile int NbTopsFan2;
int Calc2=0;                              
int hallsensor2 = 5;
long int total;
long int total1=0;
char serverName[] = "www.watersensor.tk";
int val=50;
void rpm ()    
{
NbTopsFan++;  
}
void rpm0 ()    
{
NbTopsFan0++;  
}
void rpm1 ()    
{
NbTopsFan1++;  
}
void rpm2 ()    
{
NbTopsFan2++;  
}
void add(){
   if (client.connect(serverName, 80)) {
  Serial.println("connected");
     client.print("GET /add.php?");
    client.print("main=");
    client.print(Calc);
    client.print("&&");
    client.print("sensor1=");
    client.print(Calc0);
    client.print("&&");
    client.print("sensor2=");
    client.print(Calc1);
    client.print("&&");
    client.print("sensor3=");
    client.print(Calc2);
    client.print("&&");
    client.print("all=");
    client.print(total);
  client.println(" HTTP/1.0");
    client.println("Host: www.watersensor.tk");
      client.println( "Connection: close" );
    client.println();
    client.println();
     client.stop();
}else {
    Serial.println("connection failed");
  }
}
   void valu(){
if (client.connect("www.watersensor.tk/get.php", 80)) {
             Serial.println("Read");
    char c = client.read();
    Serial.print(c);
    }
      client.stop();
  }
  
void setup()
{
pinMode(hallsensor, INPUT);
pinMode(hallsensor0, INPUT);
pinMode(hallsensor1, INPUT);
pinMode(hallsensor2, INPUT);
pinMode(val, OUTPUT);
Serial.begin(9600);
attachInterrupt(2, rpm, RISING);
attachInterrupt(3, rpm0, RISING);
attachInterrupt(4, rpm1, RISING);
attachInterrupt(5, rpm2, RISING);
  if (Ethernet.begin(mac) == 0) {
    Serial.println("Failed to configure Ethernet using DHCP");
Ethernet.begin(mac, ip);}
//data="";
total1=0;
Serial.println("connecting...");
}
void loop () {  

NbTopsFan = 0;
NbTopsFan0 = 0;      //Set NbTops to 0 ready for calculations
NbTopsFan1 = 0;
NbTopsFan2 = 0;
sei();            //Enables interrupts
delay (1000);      //Wait 1 second
cli();            //Disable interrupts
Calc = (NbTopsFan  / 7.5);
Calc0 = (NbTopsFan0  / 7.5); //(Pulse frequency x 60) / 7.5Q, = flow rate
Calc1 = (NbTopsFan1  / 7.5);     //Set NbTops to 0 ready for calculations
Calc2 = (NbTopsFan2  / 7.5);
total=  (Calc/60)+total1;
add();
valu();
    total1=total;
}

Code add.php
[Spoil] คลิกเพื่อดูข้อความที่ซ่อนไว้<?php
  include('db.php');
  $sensor1 = $_GET['main'];
  $sensor2 = $_GET['sensor1'];
  $sensor3 = $_GET['sensor2'];
  $sensor4 = $_GET['sensor3'];
  $all = $_GET['all'];
  $query = "SELECT * FROM watersensor order by id DESC LIMIT 1";
  $result = mysqli_query($db, $query);
  $array = mysqli_fetch_row($result);
  //echo "valus =";
    //echo $sensor=$_GET['sensor1'];
  $sql="INSERT INTO `watersensor`(`date`, `Main`, `Sensor1`, `Sensor2`, `Sensor3`, `total`,`On/Off`) VALUES (NOW(), '".$sensor1."','".$sensor2."','".$sensor3."','".$sensor4."','".$all."','".$array[7]."')";
  //echo $_GET['sensor1'];
  //echo $sql;
  mysqli_query($db,$sql);
  
  header("Location: index.php");
  ?>

Code get.php
[Spoil] คลิกเพื่อดูข้อความที่ซ่อนไว้  
<?php
  include("./db.php");  
  //$result=mysqli_query($db,"select * from waterflow order by id desc");
  $query = "SELECT * FROM watersensor order by id DESC LIMIT 1";
  $result = mysqli_query($db, $query);
  $array = mysqli_fetch_row($result);
    echo $array[7];
    ?>

ผลที่แสดงคือ
[IMG]http://images.temppic.com/29-01-2016/images_vertis/1454069301_0.74635200.png[/IMG]
ผมอยากถามว่าเพราะเหตุใดต้องแก้อย่างไร
ขอความกรุณาผู้รู้มาตอบด้วยครับ (ผมทำมาเป็นเดือนแล้วT_T)