PHP Communication not working...

Discussion in 'Troubleshooting' started by VMannell0, Jan 18, 2014.

  1. VMannell0

    VMannell0 New Member

    Joined:
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    I have the SD image offered on this site running Apache PHP5 etc...

    Trying to duplicate the Meteorological project this is my PHP:
    Code:
    <?php

include "php_serial.class.php";
error_reporting(E_ALL);
ini_set("display_errors", 1);
define("PORT","/dev/ttymxc3");
$serial = new phpSerial;
$serial->deviceSet(PORT);
$serial->confBaudRate(9600);
$serial->confParity("none");
$serial->confCharacterLength(8);
$serial->confStopBits(1);
$serial->confFlowControl("none");

$rawTemps=0;

if (isset($_GET["REFRESH"]))
{ 
        $serial->deviceOpen();
        $serial->sendMessage("c");
        $rawTemps = $serial->readPort();
        $serial->deviceClose();

}
else
{ 
        $serial->deviceOpen();
        $serial->sendMessage("c");
        $rawTemps = $serial->readPort();
        $serial->deviceClose();
}

?>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html> 
<head> 
        <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> 
        <title>Temperature and Humidity with DHT11</title> 
</head> 
<body>
        <h1>--UDOO SYSTEM--METEO DATA DETECTION--</h1>
        Last Detection <?php echo date('Y-m-d H:i:s', time()); ?><br/><br/>
        <?php echo $rawTemps; ?>
        <br><br><br>
        <form <?php echo $_SERVER['PHP_SELF']; ?> method="get">
                <input type="submit" name="REFRESH" value="REFRESH">
        </form>
</body> 
</html>
    How ever it can not open the port...
    "Warning: Unable to open the device in /var/www/php_serial.class.php on line 157"

    www-data is a member of "intserial" "dialout" & "www-data"

    HELP greatly appreciated!!
     
    VMannell0, Jan 18, 2014
    #1
  2. venkatbo

    venkatbo Member

    Joined:
    Jun 14, 2013
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    Have no php experience, but a clue may be here...

    Your code is setting up the serial port /dev/ttymxc3 for its operations and includes functions in php_serial.class.php. Looking on the web for an implementation of that php file, I found one at: http://www.phpclasses.org/browse/file/17926.html. Unsure if your php lib code matches or not, but, looking at line 157 (in function deviceOpen ($mode = "r+b"), I see this:
    Code:
    trigger_error("Unable to open the device", E_USER_WARNING);[/i]
    which matches the error msg you are seeing...

    So looks like one or more of the following possible issues are at play:
    • . /dev/ttymxc3 may not be defined on your system
    • . It may be being used by another app
    • . your php script is failing to open the port
    • . you are not setting the port for read/write mode per deviceOpen api signature ....

    hth,
    /venkat
     
    venkatbo, Jan 18, 2014
    #2

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