So would I use the Post method from a html Form or is there a different method?

Thanks for any info

What sort of file do I need on the server to send such to the Arduino? Sorry if this seems a silly question but the is all new to me.

An example would be great.

zoomkat

Well that was very handy, pasting http://192.168.1.20/update_db.php?celsius=45 updated the database. I then changed the get statement to client.println("GET /update_db.php?celsius=45 HTTP/1.0"); and that updated the database also. Thank you.  

At this moment I don't understand:

Code:

int d1 = readString.indexOf('<');
int d2 = readString.indexOf('>');
readString1 = (readString.substring(d1+1,d2));

and what it's trying to do or how it works. I understand .indexOf but not sure how the String works

Tony

zoomkat. Thanks for your help but I'm getting nowhere. I've tried putting in just the code to turn the LED ON/OFF but it doesn't work and the serial monitor chucks out tons of stuff. I've been on this since 7am and it's now 10:45pm so here's my code:

Code:

//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 };

Client client(server, 80);
String readString = String(30); //string for fetching data from address

void setup()
{
  Ethernet.begin(mac, ip);
  Serial.begin(9600);
  //pin mode
  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.

  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();
          //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') {
            //Turn on LED
            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 (!client.connected()) {
    Serial.println();
    Serial.println("disconnecting.");
    Serial.println("==================================");
    Serial.println("");
    client.stop();
   // for(;;);
  }
}
}

I'll have another go tomorrow perhaps!

according to the .ini Yes.

And this is what is sent to the php file:

Code:

GET /update_db.php?celsius=45 HTTP/1.1

by this line

Code:

client.println("GET /update_db.php?celsius=45 HTTP/1.1");

If this arduino is set up as a web-server why can I use this

Code:

client.println("GET /update_db.php?celsius=45 HTTP/1.1");

Should it not be Server.print which gives errors when I try to Compile?

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.

Code:

#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

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.

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

Code:

<?php
//echo ("update_db.php indicator");
$celsius = $_GET['celsius'];
//Connect to database 
$con = mysql_connect("localhost", "xxxx", "xxxx");
if(!$con)
      &#123;
      die('Could not connect: ' .mysql_error());
      &#125;
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  

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

Code:

//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

Code:

<?php
//Connect to database 
$con = mysql_connect("localhost", "xxxx", "xxxx");
if(!$con)
      &#123;
      die('Could not connect: ' .mysql_error());
      &#125;
mysql_select_db("1stClassElec", $con);

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

NOTE:
If I change

Code:

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

to

Code:

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

and then run Arduino the value of 19 gets written into the database.
Why

Code:

mysql_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.

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

@ 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:

Code:

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?

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

Code:

//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

Code:

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.

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

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?

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. :'(