php.serial class whackyness

Using Arduino Programming Questions
12

OK I may be onto something. With Uno plugged into ttyACM0 directly on the Ubuntu 10.4 PC
Using the reset resistor between 3.3v and reset (120ohms i think)
10 second delay after opening the serial port
1.5 second delay after starting to read the data from the port.
using a cron script with no browser involved running for 15 minutes at one minute intervals I got results 100% of the time.

<?php
/* Script for turning LED on and off based on temperature*/

	// Load the serial port class
	require("php_serial.class.php");
function microtime_float()
{
        list($usec, $sec) = explode(" ", microtime());
        return ((float)$usec + (float)$sec);
}

	//Initialize the class
	$serial = new phpSerial();
	//Specify the serial port to use... in this case COM1
	$serial->deviceSet("/dev/ttyACM0");
	//Set the serial port parameters. The documentation says 9600 8-N-1, so
	$serial->confBaudRate(9600); //Baud rate: 9600
	$serial->confParity("none");  //Parity (this is the "N" in "8-N-1")
	$serial->confCharacterLength(8); //Character length (this is the "8" in "8-N-1")
	$serial->confStopBits(1);  //Stop bits (this is the "1" in "8-N-1")
	$serial->deviceOpen();
	sleep(10); //wait for Arduino reset after serial open
	$serial->sendMessage(chr(10)); // start transmission
	$serial->sendMessage(chr(50));
	$serial->sendMessage(chr(13)); // end transmission
$read = '';
$theResult = '';
$start = microtime_float();

while ( ($read == '') && (microtime_float() <= $start + 1.5) ) {
        $read = $serial->readPort();
        if ($read != '') {
                $theResult .= $read;
                $read = '';
        }
}
	$serial->deviceClose();

// etc...

echo "Read data: ".$theResult."
";
	mysql_query("INSERT INTO logging (stuff,Sensor) VALUES ($theResult,'Air Temp')");

	?>

Now on to the xbees and see what happens.