<?
# Simple datalogger for digitemp.
# Christian Moen, 2007.
# chr at syntaks dot org

// Read configuration file
include("config.php");

// Loop through each line of the input data
foreach ($inData as $n=>$s)
{
	// Each run of the foreach looks at one line of input data.
	
	// Split the line into words, and place them in array $x
	$x = explode(" ",$s);
	// The sensor id is the 5th word in the line
	$sensorId = $x[4];
	// The temperature is the 7th word in the line
	$temp = $x[6];

	// If we have configured an output file for this sensor;
	if (array_key_exists($sensorId,$outFile))
	{
		// Write the temperature out to the specified file
		// This may be usefull if you want to display temperatures on a webpage etc.
		shell_exec("echo $temp > ".$outFile[$sensorId]);
	}

	// Here comes the business end of this script.
	// Each sensor has its own round robin database (RRD) where data is stored.

	// First we check to see if the database file for this sensor exists;
	if ( !file_exists($rrdDir.$n.'.rrd') )
	{
		// If not, we have to create it,
		// by running "rrdtool create" with a long list of arguments.
		// the first argument is the file name.
		
		// -s 300			sekunder mellom hver måling
		// 900, maks ant.sekunder uten data før verdi blir=unknown
		// -55 laveste temp for ds1820, 125 høyeste temp for ds1820
		
		// This is the command to be executed in the unix shell.
		$command = $rrdtool.' create '.$rrdDir.$n.'.rrd '.
		'-s 300 '.			// -s indicates the time between updates in sec. (5m is 300s)
		'DS:temp:GAUGE:900:-55:125 '.	// GAUGE indicates a spot measurment
						// 900 is the number of seconds that may pass before the value
						// is considered "unknown".
						// -55 is the minimum value the DS1820 can report
						// 125 is the maximum value the DS1820 can report
		'RRA:AVERAGE:0.5:1:576 '.	// two days at 5 min intervals
		'RRA:AVERAGE:0.5:6:672 '.	// two weeks at 30min(5*6) intervals
		'RRA:AVERAGE:0.5:24:732 '.	// two weeks at 2h intervals (120min/5min=24)
		'RRA:AVERAGE:0.5:144:1460';	// two years at 12h intervals (12*60/5=144)
		
		// The awfully long command is constructed. Lets execute it.
		shell_exec($command);
		
		// uncomment for debugging
		//echo "\n\n".$command."\n\n";
	}
	
	// rrd db is now sure to exist.. dump data into it.
	
	// uncomment to debug.
	// echo $db.": ".$rrd_insert[$db]." C\n";
	
	// The update command is a lot shorter than the create command.
	// rrdtool update file.rrd N:[temperature]
	// N meanse NOW. You can also specify a unix timestamp here.
	$command = $rrdtool.' update '.$rrdDir.$n.'.rrd N:'.$temp;
	shell_exec($command);

	// again.. debugging..
	//echo "\n$command\n";
}

?>