Send an HTTP POST to Arduino with cURL

Question

I'm trying to send an HTTP POST to my Arduino with an Ethernet shield from my server with cURL, but it doesn't work. If I send POST values through an HTML form or by Mac OS X's terminal cURL, the Arduino receive the data, so I asume the Arduino code is OK.

This is my cURL function:

function curler($what,$arduinoip){
    $url = "http://".$arduinoip;
    extract($what);
    $fields = array(
         'blue' => urlencode($blue)
    );
    foreach($fields as $key=>$value){$fields_string .= $key.'='.$value.'&';}
    $fields_strings = rtrim($fields_string, '&');
    // hasta aca todo bien
    $ch = curl_init();
    curl_setopt($ch,CURLOPT_URL, $url);
    curl_setopt($ch,CURLOPT_POST, true);
    curl_setopt($ch,CURLOPT_CONNECTTIMEOUT, 20);
    curl_setopt($ch,CURLOPT_POSTFIELDS, $fields_strings);
    //execute post
    $result = curl_exec($ch);
    $curl_errno = curl_errno($ch);
    $curl_error = curl_error($ch);
    curl_close($ch);
    if ($curl_errno > 0) {
        echo "cURL Error ($curl_errno): $curl_error\n";
    } else {
        echo "Data received: $result\n";
    }
}

I get two responses:

cURL Error (28): connect() timed out!

and

cURL Error (7): couldn't connect to host

If CURLOPT_CONNECTTIMEOUT is not declared, it returns nothing.

What is wrong with my code?

trying pinging the destination server from your server and see if it is accessible. — air4x
In urlencode($blue), what is $blue? I don't see it defined in your function. — HellaMad
What is the sketch that you are running in the Arduino side? — Sudar

Carlos Carlos · Accepted Answer · 2013-09-18T17:13:19

Do not add 'http://' before your host ip:

$url = $arduinoip;

Try to increase your time limit:

//200+ maybe?    
curl_setopt($ch,CURLOPT_CONNECTTIMEOUT, 250);

Send an HTTP POST to Arduino with cURL

1 Answers