Get Temperature From Sensor and Store on PC in CSV Files

<?php
if(_SERVER("REQUEST_METHOD"))
	exit; // avoid php execution via http request

include_once "lib/sd_340.php";
include_once "lib/vn_ftp.php";
include_once "lib/DS18B20.php";

define ("THRES_TIMER_ID", 1);

// change directory, makes directory if it doesn't exist
function change_dir($dir)
{
	$retb = ftp_chdir($dir);
	if($retb == TRUE) return TRUE;

	$dir_list = array();
	$dir_list = explode("/", $dir, 10);
	$cnt = count($dir_list);

	// move to root
	$retb = ftp_chdir("/");
	if($retb == FALSE) return FALSE;

	for($i = 0; $i < $cnt; $i++)
	{
		if($dir_list[$i] == "") continue;

		$retb = ftp_chdir($dir_list[$i]);
		if($retb == TRUE) continue;

		$ret = ftp_mkdir($dir_list[$i]);
		if($ret === FALSE) return FALSE;
		else
		{
			$retb = ftp_chdir($dir_list[$i]);
			if($retb == TRUE) continue;
			else return FALSE;
		}
	}

	return TRUE;
}

function loop_session()
{
	global $ftp_state;
	global $ftp_server, $ftp_port;
	global $ftp_id, $ftp_pass;
	global $ftp_cur_dir;

	if($ftp_state == 0)
	{
		$retb = ftp_connect($ftp_server, $ftp_port, 10);
		if($retb == FALSE)
		{
			echo "ftp - failed to connect to the FTP server.\r\n";
			return;
		}
		else $ftp_state = 1;
	}
	if($ftp_state == 1)
	{
		$retb = ftp_login($ftp_id, $ftp_pass);
		$ftp_cur_dir = "";
		if($retb == FALSE)
		{
			echo "ftp - login failed.\r\n";
			ftp_close();
			$ftp_state = 0;
		}

		$ftp_state = 2;
	}

	$tcp_state = ftp_cmd_session_state(); // checking ftp tcp session
	if($tcp_state == 0) $ftp_state = 0;
}

function loop_temperature()
{
	global $ftp_cur_dir, $ftp_cur_fn, $ftp_root_dir;
	global $update_interval;

	$timer = st_free_get_count(THRES_TIMER_ID);

	//if($timer < $update_interval)
		//return;

	// read temperature from sensor
	DS18B20_convert_t();
	$temp = DS18B20_read_temp();
	$temp = sprintf("%.01f", $temp);
	echo "$temp";

	$curr_time = date("Ymd-His");
	$today = substr($curr_time, 0, 8);
	if($today !== $ftp_cur_dir)
	{
		change_dir("/$ftp_root_dir");
		ftp_mkdir($today);
		change_dir("/$ftp_root_dir/$today");
		$ftp_cur_dir = $today;
	}

	$ftp_cur_fn = substr($curr_time, 0, 11) . '.csv';
	ftp_append($ftp_cur_fn, "$temp,");
	st_free_setup(THRES_TIMER_ID, "sec"); // reset timer
}

$ftp_server   = "192.168.0.3";
$ftp_port     = 1475;
$ftp_id       = "phpoc_device_2";
$ftp_pass     = "ilovephpoc";
$ftp_root_dir = "";
$ftp_state = 0;

$ftp_cur_fn = "";  // current filename
$ftp_cur_dir = ""; // current directory

$update_interval = 2; // 2 seconds

st_free_setup(THRES_TIMER_ID, "sec");
DS18B20_setup(1, 0);

while(1)
{
	loop_session();
	loop_temperature();
}

?>