Virtual port communication

cleary1981 · August 8, 2008

Hi,

I have a datalogger that I have configured to send data to a COM port. I want to get this data from the port into a mysql database. Can this be done with PHP?

l0ve2hat3 · August 8, 2008

class:

<?php
define ("SERIAL_DEVICE_NOTSET", 0);
define ("SERIAL_DEVICE_SET", 1);
define ("SERIAL_DEVICE_OPENED", 2);

/**
* Serial port control class
*
* THIS PROGRAM COMES WITH ABSOLUTELY NO WARANTIES !
* USE IT AT YOUR OWN RISKS !
*
* @author Rémy Sanchez <[email protected]>
* @thanks Aurélien Derouineau for finding how to open serial ports with windows
* @thanks Alec Avedisyan for help and testing with reading
* @copyright under GPL 2 licence
*/
class phpSerial
{
var $_device = null;
var $_windevice = null;
var $_dHandle = null;
var $_dState = SERIAL_DEVICE_NOTSET;
var $_buffer = "";
var $_os = "";

/**
 * This var says if buffer should be flushed by sendMessage (true) or manualy (false)
 *
 * @var bool
 */
var $autoflush = true;

/**
 * Constructor. Perform some checks about the OS and setserial
 *
 * @return phpSerial
 */
function phpSerial ()
{
	setlocale(LC_ALL, "en_US");

	$sysname = php_uname();

	if (substr($sysname, 0, 5) === "Linux")
	{
		$this->_os = "linux";

		if($this->_exec("stty --version") === 0)
		{
			register_shutdown_function(array($this, "deviceClose"));
		}
		else
		{
			trigger_error("No stty availible, unable to run.", E_USER_ERROR);
		}
	}
	elseif(substr($sysname, 0, 7) === "Windows")
	{
		$this->_os = "windows";
		register_shutdown_function(array($this, "deviceClose"));
	}
	else
	{
		trigger_error("Host OS is neither linux nor windows, unable tu run.", E_USER_ERROR);
		exit();
	}
}

//
// OPEN/CLOSE DEVICE SECTION -- {START}
//

/**
 * Device set function : used to set the device name/address.
 * -> linux : use the device address, like /dev/ttyS0
 * -> windows : use the COMxx device name, like COM1 (can also be used
 *     with linux)
 *
 * @param string $device the name of the device to be used
 * @return bool
 */
function deviceSet ($device)
{
	if ($this->_dState !== SERIAL_DEVICE_OPENED)
	{
		if ($this->_os === "linux")
		{
			if (preg_match("@^COM(\d+):?$@i", $device, $matches))
			{
				$device = "/dev/ttyS" . ($matches[1] - 1);
			}

			if ($this->_exec("stty -F " . $device) === 0)
			{
				$this->_device = $device;
				$this->_dState = SERIAL_DEVICE_SET;
				return true;
			}
		}
		elseif ($this->_os === "windows")
		{
			if (preg_match("@^COM(\d+):?$@i", $device, $matches) and $this->_exec(exec("mode " . $device)) === 0)
			{
				$this->_windevice = "COM" . $matches[1];
				$this->_device = "\\.\com" . $matches[1];
				$this->_dState = SERIAL_DEVICE_SET;
				return true;
			}
		}

		trigger_error("Specified serial port is not valid", E_USER_WARNING);
		return false;
	}
	else
	{
		trigger_error("You must close your device before to set an other one", E_USER_WARNING);
		return false;
	}
}

/**
 * Opens the device for reading and/or writing.
 *
 * @param string $mode Opening mode : same parameter as fopen()
 * @return bool
 */
function deviceOpen ($mode = "r+b")
{
	if ($this->_dState === SERIAL_DEVICE_OPENED)
	{
		trigger_error("The device is already opened", E_USER_NOTICE);
		return true;
	}

	if ($this->_dState === SERIAL_DEVICE_NOTSET)
	{
		trigger_error("The device must be set before to be open", E_USER_WARNING);
		return false;
	}

	if (!preg_match("@^[raw]\+?b?$@", $mode))
	{
		trigger_error("Invalid opening mode : ".$mode.". Use fopen() modes.", E_USER_WARNING);
		return false;
	}

	$this->_dHandle = @fopen($this->_device, $mode);

	if ($this->_dHandle !== false)
	{
		stream_set_blocking($this->_dHandle, 0);
		$this->_dState = SERIAL_DEVICE_OPENED;
		return true;
	}

	$this->_dHandle = null;
	trigger_error("Unable to open the device", E_USER_WARNING);
	return false;
}

/**
 * Closes the device
 *
 * @return bool
 */
function deviceClose ()
{
	if ($this->_dState !== SERIAL_DEVICE_OPENED)
	{
		return true;
	}

	if (fclose($this->_dHandle))
	{
		$this->_dHandle = null;
		$this->_dState = SERIAL_DEVICE_SET;
		return true;
	}

	trigger_error("Unable to close the device", E_USER_ERROR);
	return false;
}

//
// OPEN/CLOSE DEVICE SECTION -- {STOP}
//

//
// CONFIGURE SECTION -- {START}
//

/**
 * Configure the Baud Rate
 * Possible rates : 110, 150, 300, 600, 1200, 2400, 4800, 9600, 38400,
 * 57600 and 115200.
 *
 * @param int $rate the rate to set the port in
 * @return bool
 */
function confBaudRate ($rate)
{
	if ($this->_dState !== SERIAL_DEVICE_SET)
	{
		trigger_error("Unable to set the baud rate : the device is either not set or opened", E_USER_WARNING);
		return false;
	}

	$validBauds = array (
		110    => 11,
		150    => 15,
		300    => 30,
		600    => 60,
		1200   => 12,
		2400   => 24,
		4800   => 48,
		9600   => 96,
		19200  => 19,
		38400  => 38400,
		57600  => 57600,
		115200 => 115200
	);

	if (isset($validBauds[$rate]))
	{
		if ($this->_os === "linux")
		{
			$ret = $this->_exec("stty -F " . $this->_device . " " . (int) $rate, $out);
		}
		elseif ($this->_os === "windows")
		{
			$ret = $this->_exec("mode " . $this->_windevice . " BAUD=" . $validBauds[$rate], $out);
		}
		else return false;

		if ($ret !== 0)
		{
			trigger_error ("Unable to set baud rate: " . $out[1], E_USER_WARNING);
			return false;
		}
	}
}

/**
 * Configure parity.
 * Modes : odd, even, none
 *
 * @param string $parity one of the modes
 * @return bool
 */
function confParity ($parity)
{
	if ($this->_dState !== SERIAL_DEVICE_SET)
	{
		trigger_error("Unable to set parity : the device is either not set or opened", E_USER_WARNING);
		return false;
	}

	$args = array(
		"none" => "-parenb",
		"odd"  => "parenb parodd",
		"even" => "parenb -parodd",
	);

	if (!isset($args[$parity]))
	{
		trigger_error("Parity mode not supported", E_USER_WARNING);
		return false;
	}

	if ($this->_os === "linux")
	{
		$ret = $this->_exec("stty -F " . $this->_device . " " . $args[$parity], $out);
	}
	else
	{
		$ret = $this->_exec("mode " . $this->_windevice . " PARITY=" . $parity{0}, $out);
	}

	if ($ret === 0)
	{
		return true;
	}

	trigger_error("Unable to set parity : " . $out[1], E_USER_WARNING);
	return false;
}

/**
 * Sets the length of a character.
 *
 * @param int $int length of a character (5 <= length <= 
 * @return bool
 */
function confCharacterLength ($int)
{
	if ($this->_dState !== SERIAL_DEVICE_SET)
	{
		trigger_error("Unable to set length of a character : the device is either not set or opened", E_USER_WARNING);
		return false;
	}

	$int = (int) $int;
	if ($int < 5) $int = 5;
	elseif ($int >  $int = 8;

	if ($this->_os === "linux")
	{
		$ret = $this->_exec("stty -F " . $this->_device . " cs" . $int, $out);
	}
	else
	{
		$ret = $this->_exec("mode " . $this->_windevice . " DATA=" . $int, $out);
	}

	if ($ret === 0)
	{
		return true;
	}

	trigger_error("Unable to set character length : " .$out[1], E_USER_WARNING);
	return false;
}

/**
 * Sets the length of stop bits.
 *
 * @param float $length the length of a stop bit. It must be either 1,
 * 1.5 or 2. 1.5 is not supported under linux and on some computers.
 * @return bool
 */
function confStopBits ($length)
{
	if ($this->_dState !== SERIAL_DEVICE_SET)
	{
		trigger_error("Unable to set the length of a stop bit : the device is either not set or opened", E_USER_WARNING);
		return false;
	}

	if ($length != 1 and $length != 2 and $length != 1.5 and !($length == 1.5 and $this->_os === "linux"))
	{
		trigger_error("Specified stop bit length is invalid", E_USER_WARNING);
		return false;
	}

	if ($this->_os === "linux")
	{
		$ret = $this->_exec("stty -F " . $this->_device . " " . (($length == 1) ? "-" : "") . "cstopb", $out);
	}
	else
	{
		$ret = $this->_exec("mode " . $this->_windevice . " STOP=" . $length, $out);
	}

	if ($ret === 0)
	{
		return true;
	}

	trigger_error("Unable to set stop bit length : " . $out[1], E_USER_WARNING);
	return false;
}

/**
 * Configures the flow control
 *
 * @param string $mode Set the flow control mode. Availible modes :
 * 	-> "none" : no flow control
 * 	-> "rts/cts" : use RTS/CTS handshaking
 * 	-> "xon/xoff" : use XON/XOFF protocol
 * @return bool
 */
function confFlowControl ($mode)
{
	if ($this->_dState !== SERIAL_DEVICE_SET)
	{
		trigger_error("Unable to set flow control mode : the device is either not set or opened", E_USER_WARNING);
		return false;
	}

	$linuxModes = array(
		"none"     => "clocal -crtscts -ixon -ixoff",
		"rts/cts"  => "-clocal crtscts -ixon -ixoff",
		"xon/xoff" => "-clocal -crtscts ixon ixoff"
	);
	$windowsModes = array(
		"none"     => "xon=off octs=off rts=on",
		"rts/cts"  => "xon=off octs=on rts=hs",
		"xon/xoff" => "xon=on octs=off rts=on",
	);

	if ($mode !== "none" and $mode !== "rts/cts" and $mode !== "xon/xoff") {
		trigger_error("Invalid flow control mode specified", E_USER_ERROR);
		return false;
	}

	if ($this->_os === "linux")
		$ret = $this->_exec("stty -F " . $this->_device . " " . $linuxModes[$mode], $out);
	else
		$ret = $this->_exec("mode " . $this->_windevice . " " . $windowsModes[$mode], $out);

	if ($ret === 0) return true;
	else {
		trigger_error("Unable to set flow control : " . $out[1], E_USER_ERROR);
		return false;
	}
}

/**
 * Sets a setserial parameter (cf man setserial)
 * NO MORE USEFUL !
 * 	-> No longer supported
 * 	-> Only use it if you need it
 *
 * @param string $param parameter name
 * @param string $arg parameter value
 * @return bool
 */
function setSetserialFlag ($param, $arg = "")
{
	if (!$this->_ckOpened()) return false;

	$return = exec ("setserial " . $this->_device . " " . $param . " " . $arg . " 2>&1");

	if ($return{0} === "I")
	{
		trigger_error("setserial: Invalid flag", E_USER_WARNING);
		return false;
	}
	elseif ($return{0} === "/")
	{
		trigger_error("setserial: Error with device file", E_USER_WARNING);
		return false;
	}
	else
	{
		return true;
	}
}

//
// CONFIGURE SECTION -- {STOP}
//

//
// I/O SECTION -- {START}
//

/**
 * Sends a string to the device
 *
 * @param string $str string to be sent to the device
 * @param float $waitForReply time to wait for the reply (in seconds)
 */
function sendMessage ($str, $waitForReply = 0.1)
{
	$this->_buffer .= $str;

	if ($this->autoflush === true) $this->flush();

	usleep((int) ($waitForReply * 1000000));
}

/**
 * Reads the port until no new datas are availible, then return the content.
 *
 * @pararm int $count number of characters to be read (will stop before
 * 	if less characters are in the buffer)
 * @return string
 */
function readPort ($count = 0)
{
	if ($this->_dState !== SERIAL_DEVICE_OPENED)
	{
		trigger_error("Device must be opened to read it", E_USER_WARNING);
		return false;
	}

	if ($this->_os === "linux")
	{
		$content = ""; $i = 0;

		if ($count !== 0)
		{
			do {
				if ($i > $count) $content .= fread($this->_dHandle, ($count - $i));
				else $content .= fread($this->_dHandle, 128);
			} while (($i += 128) === strlen($content));
		}
		else
		{
			do {
				$content .= fread($this->_dHandle, 128);
			} while (($i += 128) === strlen($content));
		}

		return $content;
	}
	elseif ($this->_os === "windows")
	{
		/* Do nohting : not implented yet */
	}

	trigger_error("Reading serial port is not implemented for Windows", E_USER_WARNING);
	return false;
}

/**
 * Flushes the output buffer
 *
 * @return bool
 */
function flush ()
{
	if (!$this->_ckOpened()) return false;

	if (fwrite($this->_dHandle, $this->_buffer) !== false)
	{
		$this->_buffer = "";
		return true;
	}
	else
	{
		$this->_buffer = "";
		trigger_error("Error while sending message", E_USER_WARNING);
		return false;
	}
}

//
// I/O SECTION -- {STOP}
//

//
// INTERNAL TOOLKIT -- {START}
//

function _ckOpened()
{
	if ($this->_dState !== SERIAL_DEVICE_OPENED)
	{
		trigger_error("Device must be opened", E_USER_WARNING);
		return false;
	}

	return true;
}

function _ckClosed()
{
	if ($this->_dState !== SERIAL_DEVICE_CLOSED)
	{
		trigger_error("Device must be closed", E_USER_WARNING);
		return false;
	}

	return true;
}

function _exec($cmd, &$out = null)
{
	$desc = array(
		1 => array("pipe", "w"),
		2 => array("pipe", "w")
	);

	$proc = proc_open($cmd, $desc, $pipes);

	$ret = stream_get_contents($pipes[1]);
	$err = stream_get_contents($pipes[2]);

	fclose($pipes[1]);
	fclose($pipes[2]);

	$retVal = proc_close($proc);

	if (func_num_args() == 2) $out = array($ret, $err);
	return $retVal;
}

//
// INTERNAL TOOLKIT -- {STOP}
//
}
?>

example:

<?php 
include "php_serial.class.php"; 

// Let's start the class 
$serial = new phpSerial; 

// First we must specify the device. This works on both linux and windows (if 
// your linux serial device is /dev/ttyS0 for COM1, etc) 
$serial->deviceSet("COM1"); 

// Then we need to open it 
$serial->deviceOpen(); 

// To write into 
$serial->sendMessage("Hello !"); 

// Or to read from 
$read = $serial->readPort(); 

// If you want to change the configuration, the device must be closed 
$serial->deviceClose(); 

// We can change the baud rate 
$serial->confBaudRate(2400); 

// etc... 
?>

cleary1981 · August 8, 2008

your google works.. excellent

Would you recomend using php over java?

DarkWater · August 8, 2008

PHP and Java have two completely different uses. I'd recommend PHP for web scripting and stuff, and C++ for desktop stuff. =P

l0ve2hat3 · August 8, 2008

actually not google, boss. im signed up on phpclasses.com.

cleary1981 · August 11, 2008

This will be a realtime application. Im not comfortable relying on a web browser with such a critical system.

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Virtual port communication

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