File: php_serial.class.php

<?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 <thenux@gmail.com>
 * @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 $int length of a character (5 <= length <= 8)
	 * @return bool
	 */
	function confCharacterLength ($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 > 8) $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}
	//
}
?>