Notes :

• for this setup the connections are made on the ethernet shield instead of directly on the arduino. Since Fritzing misses a library with external shield I used the arduino, the pinout stays the same either way.
• check the DS18B20 datasheet for the specifications on hooking up the sensor in parasite or powered mode

Schematics :

The arduino reads the sensors every 10 seconds and passes the data to a php script on your website; which then stores the data in a text file. A second script generates a line chart of the collected data.

22 hours of temperature data

I started from Cyberspice’s code and changed the arduino code to make use of the DB18S20 and the ethernet shield.

A variable was added to the upload php script in order to store the light intensity in addition to the temperature.

The graphing script was altered to also display the minimum temperature, the maximum temperature, the current temperature and the average temperature. A raster was added for a better interpretation of the plotted data and a green line is showing the average temperature  troughout the chart.

You need to alter your ip, domain and path as I explained in the post Arduino Wireless motion detector so I won’t go into those details here.

The arduino sketch :

#include <OneWire.h>
#include <string.h>
#include <Ethernet.h>

int count = 0;
OneWire ds(8);
int HighByte, LowByte, TReading, SignBit, Tc_100, Tf_100, Whole, Fract;
int Tcount = 1;
int W[6];
int F[6];
int photocellPin = 0;     // the cell and 10K pulldown are connected to a0
int light;     // the analog reading from the sensor divider

byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
byte ip[] = {
  192, 168, 1, 36};
byte server[] = { 77, 222, 78, 32};
// String buffer
char buffer[256];

Client client(server, 80);

void setup()
{
  Ethernet.begin(mac, ip);
  Serial.begin(9600);

  delay(1000);

  // Serial.println("connecting...");

}

void loop()
{
  byte i;
  byte present = 0;
  byte data[12];
  byte addr[8];

  if ( !ds.search(addr)) {
    ds.reset_search();
    return;
  }

  ds.reset();
  ds.select(addr);
  ds.write(0x44,1);         // start conversion, with parasite power on at the end

  delay(1000);            

  present = ds.reset();
  ds.select(addr);
  ds.write(0xBE);         // Read Scratchpad

  light = analogRead(photocellPin);
  Serial.print("light intensity = ");
  Serial.print(light);
  Serial.print("\n");
  for ( i = 0; i < 9; i++) {           // we need 9 bytes
    data[i] = ds.read();
  }

  LowByte = data[0];
  HighByte = data[1];
  TReading = (HighByte << 8) + LowByte;
  SignBit = TReading & 0x8000;  // test most sig bit
  if (SignBit) // negative
  {
    TReading = (TReading ^ 0xffff) + 1; // 2's comp
  }
  Tc_100 = (6 * TReading) + TReading / 4;    // multiply by (100 * 0.0625) or 6.25

  Whole = Tc_100 / 100;  // separate off the whole and fractional portions
  Fract = Tc_100 % 100;

  if (SignBit) // If its negative
  {
    Serial.print("-");
  }
  Serial.print(Whole);
  Serial.print(".");
  if (Fract < 10)
  {
    Serial.print("0");
  }
  Serial.print(Fract);
  Serial.print(" C\n");

  if (client.connect()) {
    Serial.println("connected");
 sprintf(buffer, "HEAD /path/to/script/newtemp.php?count=%d&temp=%d.%d&light=%d HTTP/1.1", Tcount, Whole, Fract, photocell);
 client.println(buffer);
 client.println("Host: yourdomain.com");
 client.println("Connection: close");
 client.println();
 client.stop();
 Tcount++;
 }
 else {
 Serial.println("connection failed");
 }
 delay(60000);  // wait 1 minute before sending new data
}

The upload script  ‘newtemp.php’ :

<?php

if ($_SERVER['REQUEST_METHOD'] == 'HEAD') {

	$fields = explode("&", $_SERVER['QUERY_STRING']);
	$values = array();

	foreach ($fields as $field) {
		$keyval = explode("=", $field);
		$values[$keyval[0]] = $keyval[1];
	}

	$file = fopen('./tempdata.txt','a+');
	if ($file) {
		fwrite($file, time() . ':' . $values['count'] . ':' . $values['temp'] . ':' . $values['light']);
		fwrite($file, "\n");
		fclose($file);
	}
}

?>

The graphing script ‘tempgraph.php’ :

<?php

define('WIDTH', 1000);
define('HEIGHT', 520);
define('FONT', 1);
 define('FONT2',2);

// Get the temperature data
$data = array();
$file = fopen("./tempdata.txt","r");
if ($file) {
	while (!feof($file)) {
		$line = trim(fgets($file));
		if (strlen($line)) {
			$fields = explode(":", $line);
			$keyval = array();
			$keyval['time']        = $fields[0];
			$keyval['count']       = $fields[1];
			$keyval['temperature'] = $fields[2];
			$keyval['light'] 	   = $fields[3];
			$data[] = $keyval;
		}
	}

	fclose($file);
}

// Get the number of data points
$datapoints = count($data);

// Lines are chronological
$mintime = $data[0]['time'];
$maxtime = $data[$datapoints - 1]['time'];

// Temperatures need to be processed.
$mintemp = $data[0]['temperature'];
$maxtemp = $data[0]['temperature'];

foreach ($data as $datapoint) {
	$mintemp = $mintemp < $datapoint['temperature'] ?
	           $mintemp : $datapoint['temperature'];
	$maxtemp = $maxtemp > $datapoint['temperature'] ?
	           $maxtemp : $datapoint['temperature'];
	$avgtemp += $datapoint['temperature'];
	$curtemp = $datapoint['temperature'];
}
 $avgtemp = round(($avgtemp / $datapoints),2);

// Get the axis dimensions.  Round up and down to the nearest
// degree C and hour.
$lowtime  = intval($mintime / 3600) * 3600;
$hightime = (intval($maxtime / 3600) + 1) * 3600;
$difftime = $hightime - $lowtime;

$lowtemp  = intval($mintemp);
$hightemp = intval($maxtemp) + 1;
$difftemp = $hightemp - $lowtemp;

// Create the image
$image = imagecreate(WIDTH, HEIGHT);
if ($image) {
	$background = imagecolorallocate($image, 255, 255, 255);
	$black      = imagecolorallocate($image, 0, 0, 0);
	$red        = imagecolorallocate($image, 255, 0, 0);
	$blue       = imagecolorallocate($image, 0, 0, 255);
	$green		= imagecolorallocate($image, 0, 204, 5);
	$grey		= imagecolorallocate($image, 210,210,210);

	// Draw the axes
	imageline($image, 20, 20, 20, 485, $black);
	imageline($image, 15, 480, 980, 480, $black);
	imageline($image, 15, 20, 20, 20, $black);
	imageline($image, 980, 480, 980, 485, $black);

	// Draw top horizontal line
	imageline($image, 20, 20, 980, 20, $grey);

	// Draw right most vertical line
	imageline($image, 980, 20, 980, 479, $grey);

	for ($i = 3600; $i < $difftime; $i += 3600) {
		$x = 20 + (($i * 960) / $difftime);
		// Draw ticks on horizontal axis
		imageline($image, $x, 480, $x, 483, $black);
		// Draw horizontal guides
		imageline($image, $x, 479, $x, 20, $grey);
	}
	$temp = intval($lowtemp);
	for ($i = 1; $i < $difftemp; $i++) {
	    $y = 480 - (($i * 460) / $difftemp);
		// Draw ticks on vertical axis
		imageline($image, 17, $y, 20, $y, $black);

		// Draw vertical guides
		imageline($image, 21, $y, 980, $y, $grey);
		$temp = intval($temp) + 1;
		$ytemp = intval($y) - 5;
		//if($temp % 2 == 0){
			imagestring($image, FONT, 0, $ytemp, $temp . 'C', $black);
		//}
	}

	// Draw the labels
	imagestring($image, FONT, 8, 490, date("H:i", $lowtime), $black);
	imagestring($image, FONT, 970, 490, date("H:i", $hightime), $black);
	imagestring($image, FONT, 0, 475, $lowtemp . 'C', $black);
	imagestring($image, FONT, 0, 15, $hightemp . 'C', $black);

	// Draw min, max and avg
	imagestring($image, FONT2, 700, 430, "Cur. temp : " . $curtemp . " °C",$black);
	imagestring($image, FONT2, 700, 450, "Avg. temp : " . $avgtemp . " °C",$green);
	imagestring($image, FONT2, 850, 430, "Min. temp : " . $mintemp . " °C",$blue);
	imagestring($image, FONT2, 850, 450, "Max. temp : " . $maxtemp . " °C",$red);

	// Draw avg line

	$avgtemp = 480 - ((($avgtemp - $lowtemp) * 460) / $difftemp);
	imageline($image,20, $avgtemp, 980, $avgtemp, $green);

	// Draw the temperature points

	// Position of the first point
	$prevx = (($data[0]['time'] - $lowtime) * 960) / $difftime;
	$prevy = (($data[0]['temperature'] - $lowtemp) * 460) / $difftemp;

	// Draw line from previous point to current point
	for ($i = 1; $i < $datapoints; $i++) {
		$x = (($data[$i]['time'] - $lowtime) * 960) / $difftime;
		$y = (($data[$i]['temperature'] - $lowtemp) * 460) / $difftemp;
		imageline($image, $prevx + 20, 480 - $prevy, $x + 20, 480 - $y, $red);
		$prevx = $x;
		$prevy = $y;
	}

	// Finally time and date stamp
	$generated = 'Generated: ' . date("r");
	imagestring($image,
	            FONT,
	            WIDTH - 15 - (imagefontwidth(FONT) * strlen($generated)),
	            HEIGHT - 15,
	            $generated,
	            $blue);

	// Output the image
	header('Content-Type: image/png');
	imagepng($image);

	// Destroy it
	imagedestroy($image);
}

?>

I will soon post some improvements on the scripts :

• averaging 6 readings ( 1 minute ) to 1 datapoint to get rid of the noise
• let the script fill one text file for each day, so you can look at a history over several days
• split up data into different charts
• last but not least, trying to add the S65 in the game : showing the current sensor readings or a graph

Please leave a comment or send me a link to show your arduino projects!

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No problem thusfar, you just wander to System > Administration > Users and Groups

Note: You might want to skip changing your users’ password when during installation  you’ve selected to also use the users’ password to decrypt your home folder. I’m not saying it will, but it could cause problems when the configuration of your login password and the decrypt password don’t match.

You click the user who’s password you wish to change, click properties and enter your current (long and typo-prone) password

Next you enter a finger-friendly password, and confirm before you hit ‘Change password’…

Instead of getting a message that reads ‘Your password has been changed’ you get …

Well I know it’s simple, that’s kind of where I’m getting at!

After some swearing I realised I might as well use the command line to get things done…

Open a terminal and enter

sudo passwd yourusername

You will be asked to enter the current password, enter a new password and confirm.

Thataa! Easy as 123! Damn now I have to go and change my password again…

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I’ll assume you haven’t already installed any of the necessary packages to run the Arduino IDE.

1. First open a terminal ( Applications > Accesories > Terminal ), paste the following code and hit enter :

sudo apt-get install sun-java6-jre sun-java6-bin sun-java6-jdk
sun-java6-fonts sun-java6-plugin gcc-avr avr-libc

 
2. Next we need to uninstall Ubuntu’s braille support as it is known to cause conflicts with the Arduino IDE.

To do so go back to the terminal and enter :

sudo apt-get remove brltty

 
3. Now we need to setup Java
GNU’s Java doesn’t support the Arduino so to fix this run the command

sudo update-alternatives --config java

 
This will show you a list of java alternatives installed on the machine.
Select the entry ‘java-6-sun’

4. Now we are ready to download and install the arduino environment

Click here to download version 17 of the Arduino IDE. Alternatively go here to download a specific version.

5. Copy the downloaded file to your home directory ( saved by default in /home/username/downloads )

Extract the downloaded file into your home directory ( right-click > extract here ).

6. To start the Arduino IDE open the arduino-0017 folder and double click the arduino file, when prompted choose Run.

If you want to start the Arduino IDE from the command line, cd into the folder

cd /home/username/arduino-0017

 
and start the IDE with the command

./arduino

I however prefer to have a launcher to quickstart applications.

1. Download this icon to your desktop ( right-click > Save image as… )

2. Open a terminal, go to your desktop and copy the image to /usr/share/icons

cd Desktop/
sudo cp arduino.png /usr/share/icons/

 
3. Next right click the top panel and select Add to panel…

5. Select the first entry ‘Custom Application Launcher’ and hit Add

6.In the Create Launcher window enter

A name for the launcher :

Arduino

 
The command to be executed when the launcher is clicked :

bash -c "cd /home/yourusername/arduino-0017/; ./arduino"

 
And any comment you want to add :

starts the Arduino IDE

 
Now click on the spring icon and go to the /usr/share/icons/ folder and select the arduino.png image.

Your Launcher should look like this

That was it! You’re all setup to hack and thinker with your Arduino on Ubuntu 9.10.

Now run along a go blink some LEDs.

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Introduction

This is a step by step guide for installing and setting up a webdev server on a ubuntu machine. I will show you how to install the lampp stack using XAMPP version 1.7.1 on Ubuntu 9.10.

You can follow the exact same steps for setting up XAMPP version 1.7.2

Follow these steps to install XAMPP:

1. For starters you need to go to the official XAMPP website and download XAMPP for Linux version 1.7.1,  click here to download XAMPP for Linux version 1.7.1

Make sure you download XAMPP 1.7.1  if you want to use it together with wordpress.  XAMPP 1.7.2 uses PHP 5.3.0 which causes some problems when used in combination with wordpress 2.8.4

2. Place the downloaded .tar.gz archive on your desktop if it wasn’t already saved there by default.

3. Open a terminal ( Applications > Accessoires > Terminal )

4. Go to your desktop (or any other location where you placed the downloaded file)

cd Dekstop

 
5. Login as the super admin

sudo -s

 
6. Untarball the compressed file to the /opt directory

tar xvfz xampp-linux-1.7.1.tar.gz -C /opt

 
The above command installs xampp in the /opt/lampp directory

7. Start xampp by giving the command

/opt/lampp/lampp start

 
8. After starting xampp open a browserwindow and go to localhost

If all went well you’ll see this page

9. After choosing your language you’ll be forwarded to the welcome page

10. Go to the security page by clicking Security in the left menu.

You’ll see that everything is unsecured at the moment

When XAMPP will be used for local development these settings won’t matter much. It is good practice however to set it up securely.

Next I’ll show you how to setup security

 
11. Copy the code on the bottom of the security page and then paste it into a terminal

/opt/lampp/lampp security

 
This will start an interactive program to help you configure security settings

12. Type yes when prompted to enter a password and enter a secure password twice

13. Turn off MySQL network accesibility by entering yes, MySQL will now restart so the setting can take effect

14. You’ll be prompted to set a password for phpMyAdmin, do so.

15. And again for setting a MySQL root password, make sure you write this one down or you’ll be in trouble later on.

16. Now set a password for user nobody.

This should complete the security setup procedure.

To confirm everything went ok, open a browserwindow and go to localhost

17. You’ll be prompted for a username and password.

the username is ‘lampp’
the password is the one you entered in step 12

18. Go the the security pages

This should show all subjects are now secured..

Place content you want to add to the webserver in the root web directory located in

/opt/lamp/htdocs

 
To make things easier we’ll add a link to the htdocs folder to a folder in our home directory.

You can do this in a terminal by typing

mkdir ~/public_html

 
Or just right-click in your home folder and create a new folder named ‘public_html’

19. Now we’ll make a link from the new folder to /opt/lampp/htdocs , open a terminal and enter

sudo ln -s ~/public_html /opt/lampp/htdocs/

 
20. To setup permissions for the htdocs folder, go to the terminal (still logged in as super user) and type

chown  yourusername -R /opt/lampp/htdocs

 
This changes the ownership of the htdocs folder to your user, the -R option makes the command recursive so all permissions of folders and files inside htdocs are changed aswell.
 

Congratulations that was it! Well sort of…

 
After restarting your computer you have to manually start the server by entering

/opt/lampp/lampp start

 
in a terminal.

EDIT: MiD-AwE pointed out he had to install the ia32 libraries when installing XAMPP on Ubuntu 9.10 64-bit. The ia32 library is needed when installing a 64-bit version on a AMD64 or ia64-system.

To do this open a terminal and type

sudo apt-get install ia32-libs

If you want xampp to automatically start at boottime, follow these steps.

 
EDIT : Or as MiD-AwE suggested you can go to System > Preferences and add an entry

 /opt/lampp/lampp start

 
to “Startup Applications”

If you want to use a GUI to start and stop xampp do the following:

1. Open a terminal and type

sudo gedit ~/.local/share/applications/xampp-control-panel.desktop

 
2. Paste this code in the new empty file in gedit

[Desktop Entry]
Comment=Start and Stop XAMPP
Name=XAMPP Control Panel
Exec=gksudo python /opt/lampp/share/xampp-control-panel/xampp-control-panel.py
Icon[en_CA]=/usr/share/icons/Humanity/devices/24/network-wired.svg
Encoding=UTF-8
Terminal=false
Name[en_CA]=XAMPP Control Panel
Comment[en_CA]=Start and Stop XAMPP
Type=Application
Icon=/usr/share/icons/Humanity/devices/24/network-wired.svg

Change this line (twice) to match the location of the icon you want to use.

Icon[en_CA]=/usr/share/icons/Humanity/devices/24/network-wired.svg

 
3. The xampp control panel should now show up in Applications > Other

You should get to see something like this :

That was it!

Now run along and go do something usefull

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