Arduino ethernet webclient php script and mysql

I imagine I need a client as my idea was to have the Arduino write to the mysql database, there could be more than one Arduino sending the same sort of data. When I wish to view any results I would just read the results from the database in a web page.

The Serial.print was only to check to right data was being sent but I've just tried GET and Post but still nothing appears in the database.

I still don't understand why nothing is written to the database. :cry:

OK,

First you have to fix the webserver to work properly. Build two php pages, one with a form in which you can fill in two fields - time and temperature - and a second one to process the data posted and stores it into a database.

If the form works you can let the Arduino's do the posting. An example of the layout of a POST command can be found here:

robtillaart

Can you explain why I need a form as I want this to be automated and have the Arduino send data direct to the mysql database?

Surely the Arduino can do that using GET or perhaps PUT?

have the Arduino send data direct to the mysql database?

That it can not do. There is nothing in MySQL that listens to the serial port. You can have the Arduino with Ethernet shield do GET, PUT, or POST, depending on which is easier for you to understand/get working. Some other application, like a PHP script, needs to get the data, and construct the SQL commands to insert the data in the database.

robtillaart

Perhaps I've confused things more than I'm confused.

I'm trying to send data using client.print via ethernet from an Arduino client to my home web server which runs on a laptop. The serial.print is just so I can see what's happening using the "Serial Monitor".

I'm trying to get the Arduino to pass data to update_db.php which should load it into the database 1stClassElec table device_1.

Sorry, and grateful for your help

I'm trying to send data using client.print via ethernet from an Arduino client to my home web server which runs on a laptop. The serial.print is just so I can see what's happening using the "Serial Monitor".

I'm trying to get the Arduino to pass data to update_db.php which should load it into the database 1stClassElec table device_1.

Well, the issue may not be with the arduino, but with the setup on your server. Below is some arduino ethernet test code that sends a GET request to my apache web server for the contents of the text file, and the apache web server sends the text of the file back to the arduino to verify that the ethernet shield is working. You could append your data to the URL as a query_string to send to your server. You will have to develop the data handling programs for your server.

//zoomkat 11-13-10
//simple ethernet client test code
//for use with IDE 0021 and W5100 ethernet shield
//modify the arduino lan ip address as needed
//open serial monitor to see what the arduino receives
//push the shield reset button to run client again

#include <SPI.h>
#include <Ethernet.h>

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
byte ip[] = { 192, 168, 1, 102 };
byte server[] = { 208, 104, 2, 86 }; // zoomkat

Client client(server, 80);

void setup()
{
  Ethernet.begin(mac, ip);
  Serial.begin(9600);
  Serial.println("starting simple arduino client test");
  Serial.println();

  delay(1000);

  Serial.println("connecting...");

  if (client.connect()) {
    Serial.println("connected");
    client.println("GET /~shb/arduino.txt HTTP/1.0");
    client.println();
  } else {
    Serial.println("connection failed");
  }
}

void loop()
{
  if (client.available()) {
    char c = client.read();
    Serial.print(c);
  }

  if (!client.connected()) {
    Serial.println();
    Serial.println("disconnecting.");
    Serial.println("==================================");
    Serial.println("");
    client.stop();
    for(;;);
  }
}

zoomkat, thanks for info. I've created file below, please check it through in case I'm making a mistake.

//zoomkat 11-13-10
//simple ethernet client test code
//for use with IDE 0021 and W5100 ethernet shield
//modify the arduino lan ip address as needed
//open serial monitor to see what the arduino receives
//push the shield reset button to run client again

#include <SPI.h>
#include <Ethernet.h>

byte mac[] = {0x90, 0xA2, 0xDA, 0x00, 0x11, 0xAC };
byte ip[] = { 192, 168, 1, 19 };
byte server[] = { 192,168,1,20 }; // zoomkat

Client client(server, 80);

void setup()
{
  Ethernet.begin(mac, ip);
  Serial.begin(9600);
  Serial.println("starting simple arduino client test");
  Serial.println();

  delay(1000);

  Serial.println("connecting...");

  if (client.connect()) {
    Serial.println("connected");
    client.println("GET /http://192.168.1.20/var/www/arduino.txt HTTP/1.0");
    client.println();
  } else {
    Serial.println("connection failed");
  }
}

void loop()
{
  if (client.available()) {
    char c = client.read();
    Serial.print(c);
  }

  if (!client.connected()) {
    Serial.println();
    Serial.println("disconnecting.");
    Serial.println("==================================");
    Serial.println("");
    client.stop();
    for(;;);
  }
}

and the responce I get back

starting simple arduino client test



connecting...

connected

HTTP/1.1 404 Not Found

Date: Sat, 18 Dec 2010 08:57:55 GMT

Server: Apache/2.2.14 (Ubuntu)

Vary: Accept-Encoding

Content-Length: 312

Connection: close

Content-Type: text/html; charset=iso-8859-1



<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p>The requested URL /http://192.168.1.20/var/www/arduino.txt was not found on this server.</p>
<hr>
<address>Apache/2.2.14 (Ubuntu) Server at 127.0.1.1 Port 80</address>
</body></html>


disconnecting.

==================================

The arduino.txt file does exist.
I hope someone can help, thanks.

    client.println("GET /http://192.168.1.20/var/www/arduino.txt HTTP/1.0");

Why is there a slash in front of http?
If you paste the string starting with http in a browser, is the file found?

client.println("GET /http://192.168.1.20/var/www/arduino.txt HTTP/1.0");

==>

client.println("GET /arduino.txt HTTP/1.0");

you allready connected to the server, port 80 == HTTP, /var/www is probably the docroot of your webserver...

@ PaulS. If I pasta http://192.168.1.20/arduino.txt into a browser it is found and shows my inserted text.

@robtillart.

client.println("GET /arduino.txt HTTP/1.0");

gives:

starting simple arduino client test



connecting...

connected

HTTP/1.1 200 OK

Date: Sat, 18 Dec 2010 13:48:52 GMT

Server: Apache/2.2.14 (Ubuntu)

Last-Modified: Sat, 18 Dec 2010 08:55:24 GMT

ETag: "1fbee-5-497ab729b1eef"

Accept-Ranges: bytes

Content-Length: 5

Vary: Accept-Encoding

Connection: close

Content-Type: text/plain



test


disconnecting.

So is this working?

If so what is wrong with my code which stops me writing to the database?

If so what is wrong with my code which stops me writing to the database?

The arduno is working just fine. The issue is on your server and what application you are using with apache to interpet what is sent and the manipulaton of your database. If the server is on a linux box, then you need to have some linux compatable application to perform the database operations when apache gets the incomming request. In the past I think Perl was often used as a CGI application. PHP might have a version for linux.

zoomkat.

Thanks for getting back. I have Xubuntu with LAMP.

If I type the value into my PHP script the database gets filled, what I don't understand is how or through what the Arduino passes info to the PHP.

If you have any ideas where I should look I'd much appreciate it.

Thanks again

Tony

You might post your PHP code that works to see what you have. Below shows how to append a GET request (query_string, the string after the ?) to a URL. In windows, apache sets the query_string as an environmental varable, from which an application started by apache collects the data. Note that some characters have special meaning and can't be put in a query_string.

client.println("GET /arduino.txt HTTP/1.0");

With query_string added:

client.println("GET /arduino.php?put-your-data-here HTTP/1.0");

Well this is what I'm trying to run. The Arduino code is yours, modified to update the database with a value.

//zoomkat 11-13-10
//simple ethernet client test code
//for use with IDE 0021 and W5100 ethernet shield
//modify the arduino lan ip address as needed
//open serial monitor to see what the arduino receives
//push the shield reset button to run client again

#include <SPI.h>
#include <Ethernet.h>

byte mac[] = {0x90, 0xA2, 0xDA, 0x00, 0x11, 0xAC };
byte ip[] = { 192, 168, 1, 19 };
byte server[] = { 192,168,1,20 }; // zoomkat

Client client(server, 80);

void setup()
{
  Ethernet.begin(mac, ip);
  Serial.begin(9600);
  Serial.println("starting simple arduino client test");
  Serial.println();

  delay(1000);

  Serial.println("connecting...");

  if (client.connect()) {
    Serial.println("connected");
    //client.println("GET /arduino.txt HTTP/1.0");
    client.println("GET /update_db.php?celsius=18 HTTP/1.0");
    client.println();
  } else {
    Serial.println("connection failed");
  }
}

void loop()
{
  if (client.available()) {
    char c = client.read();
    Serial.print(c);
  }

  if (!client.connected()) {
    
    
    Serial.println();
    Serial.println("disconnecting.");
    Serial.println("==================================");
    Serial.println("");
    client.stop();
    for(;;);
  }
}

And the PHP script

<?php
//Connect to database 
$con = mysql_connect("localhost", "xxxx", "xxxx");
if(!$con)
      {
      die('Could not connect: ' .mysql_error());
      }
mysql_select_db("1stClassElec", $con);

mysql_query("INSERT INTO device_1(temp) VALUES (celsius)");
mysql_close($con);
?>

NOTE:
If I change mysql_query("INSERT INTO device_1(temp) VALUES (celsius)");
to

mysql_query("INSERT INTO device_1(temp) VALUES (19)");

and then run Arduino the value of 19 gets written into the database.
Whymysql_query("INSERT INTO device_1(temp) VALUES (celsius)"); doesn't pass its value of celsius=18 from the Arduino script is a mystery to me at the moment.

In the PHP script, there are $_GET and $_POST variables that contain the data passed to the script, depending on the method used to to activate the script.

The $_GET variables are name/value pairs. The value is obtained from the name:

$val = $_GET['celcius'];

It is the value ($val) that you want to store in the database.

@ PaulS I was just reading a web page which is similar to your explanation. My PHP script is working and now looks like this:

<?php
//echo ("update_db.php indicator");
$celsius = $_GET['celsius'];
//Connect to database 
$con = mysql_connect("localhost", "xxxx", "xxxx");
if(!$con)
      {
      die('Could not connect: ' .mysql_error());
      }
mysql_select_db("1stClassElec", $con);

mysql_query("INSERT INTO device_1(temp) VALUES ('$celsius')");
mysql_close($con);
?>

Thanks go to all of you for your help, and I expect I'll be back soon with another question :slight_smile:

Ok back again. I would like my Arduino web-client to write data to the mysql database every 15 minutes.

What would be the best way to do the time interval counting?

As I see it, it could be done by the Arduino but could my web server poll the Arduino or what about the timer_ntp. I'd need some examples with the last two suggestions if they are good ideas.

As I see it, it could be done by the Arduino but could my web server poll the Arduino

Yes. The Arduino could use millis() to determine the "time", and send data only once every 15 minutes. Or the Arduino could do nothing except wait for a client connection, and, in response to the client connection, return the temperature.

Which approach to use depends on what you are comfortable programming.

Well in my endeavour to learn Arduino Ethernet I'm still unable to get the Arduino web-client to accept commands from a server PC. Also I'm unable to get web-server to send data to a mysql database.

So I've written (probably poorly) code which I 95% understand that accepts commands from a browser.
http://192.168.1.19/?7=1 turns digital 7 on
http://192.168.1.19/?7=0 turns digital 7 off
http://192.168.1.19/?A=0 gets the value from analogue 0, prints what looks like the correct string in the web-browser but it won't write to a mysql.

#include <SPI.h>
//#include <WString.h>
#include <Ethernet.h>

byte mac[] = { 0x90, 0xA2, 0xDA, 0x00, 0x11, 0xAC }; //physical mac address
byte ip[] = { 192, 168, 1, 19 };                  // ip in lan
byte gateway[] = { 192, 168, 1, 1 };                  // internet access via router
byte subnet[] = { 255, 255, 255, 0 };                   //subnet mask
//byte server[] = { 192,168,1,20 };
Server server(80);                                      //server port
byte sampledata=50;            //some sample data - outputs 2 (ascii = 50 DEC)             
int ledPin = 4;  // LED pin
char link[]="http://www.scienceprog.com/"; //link data
String readString = String(30); //string for fetching data from address
boolean LEDON = false; //LED status flag
//#######################################
   #define READING_PIN 0
    double R1 = 10000.0; //resistance put in parallel
    double V_IN = 5.0;
    double A = 1.129148e-3;
    double B = 2.34125e-4;
    double C = 8.76741e-8;
    double K = 9.5; // mW/dec C – dissipation factor
    double SteinhartHart(double R)
    {
    // calculate temperature
    double logR  = log(R);
    double logR3 = logR * logR * logR;
    return 1.0 / (A + B * logR + C * logR3 );
    }
    int celsius;//Global declare celsius
//#######################################
void setup(){
//start Ethernet
  Ethernet.begin(mac, ip, gateway, subnet);
//pinMode;
pinMode(7,OUTPUT); digitalWrite(7,LOW);  // I use this pin as GND for the LED.
pinMode(8,OUTPUT); // Sample output, unable to use built-in LED at pin 13 because Ethernet Shield uses pins 10,11,12,13.
  
//enable serial datada print  
    Serial.begin(9600);
}
void loop(){
    readString="";//Clear readString before filling
    // Create a client connection
    Client client = server.available();
      if (client) {
      while (client.connected()) {
        if (client.available()) {
          char c = client.read();
          //read char by char HTTP request
          if (readString.length() < 30)  { 
          //store characters to string 
          readString.concat(c);
          Serial.println(readString);
          }  
          //output chars to serial port
          Serial.print(c);
            //if HTTP request has ended
            if (c == '\n') {
            //lets check if LED should be lighted
            Serial.println(readString.substring(6,9));//for test to allow readString to be viewed
              if(readString.substring(6,9)=="7=1") {//read the last 3 information characters from URL
              // Serial.println(readString);
              //set digital 7 HIGH
              Serial.println("HIGH");
             digitalWrite(7, HIGH);    // set the LED on
              readString="";//clear readString
              }
                if(readString.substring(6,9)=="7=0") {
                //set digital 7 LOW
                Serial.println("LOW");
                digitalWrite(7, LOW);    // set the LED OFF
                readString="";//clear readString           
                }
              if(readString.substring(6,9)=="A=0")  {
              //readAnal 0 temp
              ReadTemp();
              Serial.println("for test");
              client.print("GET http://192.168.1.20/update_db.php?celsius=");
              client.print(celsius);
              client.println(" HTTP/1.0");
              client.println("Host: http://192.168.1.20");
              client.println();
              readString="";//clear readString            
              } 
          
          //clearing string for next read
          readString="";
          //stopping client
          client.stop();
            }
          }
        }
      }
 }
//########################################################################
void ReadTemp() {
//Serial.print("I'm at ReadTemp ");
    double adc_raw = analogRead(READING_PIN);
    double V =  adc_raw / 1024 * V_IN;//Serial.println(adc_raw);
    double R_th = (R1 * V ) / (V_IN - V);//calculate resistance
    double kelvin = SteinhartHart(R_th) - V*V/(K * R_th);
    celsius = kelvin - 273.15;//was double but changed to int to remove decimal places
    Serial.println();
    delay(1000);
    
    return;
}
//#######################################################################

Can anyone see and explain what's wrong as I've spent all day on this with no answer.

All I want is an Arduino with Ethernet Shield that can accept commands from a web-server PC and send values to a mysql database on the same to the web-server PC.

Thanks for any help.

Tony

Do you have error handling turned on in PHP?