Buffer problems Adafruit Thermal Printer connected to Raspbe

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SolidTerre
 
Posts: 2
Joined: Mon Mar 23, 2015 2:06 pm

Buffer problems Adafruit Thermal Printer connected to Raspbe

Post by SolidTerre »

My Raspberry Pi B+ is hosting a PHP website and that is connected to a thermal printer through serial interface (RS232 Adafruit thermal printer).

So I used the library PHPSerial to write to my printer through the web (page is hosted on the raspberry pi) with some simple code (when the page loads->write to the printer).

The problem is:

Communication problems: I have to load the page twice before it actually prints something (so buffer is filled twice before it prints the first written data) Sometimes it prints weird stuff like on this image:

Image

Here are my two files:

Code: Select all

Index.php :

<?php

include 'PhpSerial.php';

//create object of class PhpSerial
$serial = new PhpSerial;

//Specify the device
$serial->deviceSet("/dev/ttyAMA0");

//Configure baud rate, parity, length etc.
$serial->confBaudRate(19200);
$serial->confParity("none");
$serial->confCharacterLength(8);
$serial->confStopBits(1);
$serial->confFlowControl("none");

//Open serial
$serial->deviceOpen();

//write to it
$serial->sendMessage("Hello ! This is a test !");

$serial->serialflush();

$serial->deviceClose();

?>

This is a test
PHPSerial 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 WARRANTIES !
 * USE IT AT YOUR OWN RISKS !
 *
 * @author Rémy Sanchez <[email protected]>
 * @author Rizwan Kassim <[email protected]>
 * @thanks Aurélien Derouineau for finding how to open serial ports with windows
 * @thanks Alec Avedisyan for help and testing with reading
 * @thanks Jim Wright for OSX cleanup/fixes.
 * @copyright under GPL 2 licence
 */
class PhpSerial
{
    public $_device = null;
    public $_winDevice = null;
    public $_dHandle = null;
    public $_dState = SERIAL_DEVICE_NOTSET;
    public $_buffer = "";
    public $_os = "";

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

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

        $sysName = php_uname();

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

            if ($this->_exec("stty") == 0) {
                register_shutdown_function(array($this, "deviceClose"));
            } else {
                register_shutdown_function(array($this, "deviceClose"));

                //trigger_error(
                //    "No stty available, unable to run.",
                //    E_USER_ERROR
                //);
            }
        } elseif (substr($sysName, 0, 6) === "Darwin") {
            $this->_os = "osx";
            register_shutdown_function(array($this, "deviceClose"));
        } elseif (substr($sysName, 0, 7) === "Windows") {
            $this->_os = "windows";
            register_shutdown_function(array($this, "deviceClose"));
        } else {
            trigger_error("Host OS is neither osx, linux nor windows, unable " .
                          "to 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
     * -> osx : use the device address, like /dev/tty.serial
     * -> windows : use the COMxx device name, like COM1 (can also be used
     *     with linux)
     *
     * @param  string $device the name of the device to be used
     * @return bool
     */
    public function deviceSet($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 ($this->_os === "osx") {
                if ($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 . " xon=on BAUD=9600")
                        ) === 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 $mode Opening mode : same parameter as fopen()
     * @return bool
     */
    public function deviceOpen($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
     */
    public 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  $rate the rate to set the port in
     * @return bool
     */
    public function confBaudRate($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 === "osx") {
                $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;
            }

            return true;
        } else {
            return false;
        }
    }

    /**
     * Configure parity.
     * Modes : odd, even, none
     *
     * @param  string $parity one of the modes
     * @return bool
     */
    public function confParity($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],
                $out
            );
        } elseif ($this->_os === "osx") {
            $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  $int length of a character (5 <= length <= 8)
     * @return bool
     */
    public function confCharacterLength($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,
                $out
            );
        } elseif ($this->_os === "osx") {
            $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 $length the length of a stop bit. It must be either 1,
     *                       1.5 or 2. 1.5 is not supported under linux and on
     *                       some computers.
     * @return bool
     */
    public function confStopBits($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",
                $out
            );
        } elseif ($this->_os === "osx") {
            $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 $mode Set the flow control mode. Availible modes :
     *                      -> "none" : no flow control
     *                      -> "rts/cts" : use RTS/CTS handshaking
     *                      -> "xon/xoff" : use XON/XOFF protocol
     * @return bool
     */
    public function confFlowControl($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],
                $out
            );
        } elseif ($this->_os === "osx") {
            $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 $arg   parameter value
     * @return bool
     */
    public function setSetserialFlag($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  $waitForReply time to wait for the reply (in seconds)
     */
    public function sendMessage($str, $waitForReply = 0.1)
    {
        $this->_buffer .= $str;

        if ($this->autoFlush === true) {
            $this->serialflush();
        }

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

    /**
     * Reads the port until no new datas are availible, then return the content.
     *
     * @param int $count Number of characters to be read (will stop before
     *                   if less characters are in the buffer)
     * @return string
     */
    public function readPort($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" || $this->_os === "osx") {
            // Behavior in OSX isn't to wait for new data to recover, but just
            // grabs what's there!
            // Doesn't always work perfectly for me in OSX
            $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") {
            // Windows port reading procedures still buggy
            $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;
        }

        return false;
    }

    /**
     * Flushes the output buffer
     * Renamed from flush for osx compat. issues
     *
     * @return bool
     */
    public function serialflush()
    {
        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}
    //

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

            return false;
        }

        return true;
    }

    public function _ckClosed()
    {
        if ($this->_dState === SERIAL_DEVICE_OPENED) {
            trigger_error("Device must be closed", E_USER_WARNING);

            return false;
        }

        return true;
    }

    public 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}
    //
}
What am I missing here?

Thank you.
SolidTerre

User avatar
adafruit_support_rick
 
Posts: 35092
Joined: Tue Mar 15, 2011 11:42 am

Re: Buffer problems Adafruit Thermal Printer connected to Ra

Post by adafruit_support_rick »

Does the printer work properly with the adafruit library and sample code?
https://github.com/adafruit/Python-Thermal-Printer

User avatar
SolidTerre
 
Posts: 2
Joined: Mon Mar 23, 2015 2:06 pm

Re: Buffer problems Adafruit Thermal Printer connected to Ra

Post by SolidTerre »

Hey !

Thanks for your answer.

Yes, it is working with the Python file.

I'm thinking about generating a Python file trough PHP and then executing it, not the greatest solution, but if I have no choice ... :-(

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