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I have been working on MSP430 for sometime now. It is an TI (Texas Instruments ) chip. Very fun to play with. We are using a MSP430FG461x series experimental board. This little experimental board has all the bells and whistles one may need to create any application from a home automation controller to a simple step-motor driver. TI provides very good documentation for this grown up toy.

Our first lab homework for this baby was :

By using the MSP430 FG4618 Microcontroller, write a program that controls the LED #1, #2,#4.When we perpetually push the two buttons at the right bottom corner of the board, all ofthe LEDs turn on.When we push perpetually one of the buttons, only the LED #4 blinks, the others turn off.When we push no buttons, the LED #1 and #2 blinks complementarily and the LED#4 turnsoff.

My biggest problem with this exercise was to find what led was connected to what port. However in the end I figured it all out.

Below you will find the program :

#include <msp430xG46x.h>

void initPortPins(void);

void main(void)
{
	 WDTCTL=WDTPW + WDTHOLD;
	 initPortPins();
	 while(1) {
	 	if (P1IN == (0x00))
	 	{
			P2OUT |= 0x06;
			P5OUT |= 0x02;
		}
		else if (P1IN == 0x03)
		{
			P2OUT &= 0x00;
			P5OUT &= 0x00;
			P2OUT |= 0x02;
			__delay_cycles (40000);
			P2OUT &= 0x00;
			P2OUT |= 0x04;
			__delay_cycles (40000);
		}
		else
		{
			P2OUT &= 0x00;
			P5OUT &= 0x00;
			__delay_cycles (40000);
			P5OUT |= 0x02;
			__delay_cycles (40000);
		}
	 }
};

void initPortPins(void)
{
  P1DIR = 0x00;	// Set P2.2,1 as outputs
  P5DIR = 0x02; // Set P5.1 as output
  P2DIR = 0x06; // Set P2.1 to 1
};

You see we learned that we should NOT set any environment variables while using demo u-boot image which was downloaded from here. In fact what we did is we created our own Ångström image (from Ångström site) and simply installed that to our Linux partition of our SDHC card. And it worked beautifully. Though I must say first boot is a drag, very very slow.

Ran to some problems again. It seems BeagleBoard only works with DVI-D LCD’s and we had a HDMI to VGA instead of a HDMI to DVI-D cable.We ended up connecting to it from SSH and installing our programs like that. We really don’t need an LCD any time soon. And to connect to it from SSH we had to learn it’s IP from terminal. So no problems there. And we were very happy with the outcome.

Installing python libraries; as installing python libraries go this one was a little tricky. You see it seems that Ångström doesn’t update its python libs that frequently. So calling the package by

opkg intall python-pycrypto

Didn’t quite work since installed itself to python2.5 directory. Had to install pycrypto manually. I hated every moment of it. I  than uploaded my own program and I was very happy with the outcome. The program worked perfectly.

Stay tuned for more updates on The Black Box project! Remember you can find it athttp://sourceforge.net/projects/theblackbox/ .

Live coding!

The CVS code is as follows

cvs -d:pserver:anonymous@theblackbox.cvs.sourceforge.net:/cvsroot/theblackbox login

cvs -z3 -d:pserver:anonymous@theblackbox.cvs.sourceforge.net:/cvsroot/theblackbox co -P modulename

I am sorry to say due to some weird problem you can not view the CVS modules from Sourceforge. You will need to use some kind of client. I am currently using Eclipse as my development IDE hence all my CVS materials comes from that. I have heard that TortoiseCVS is quite neat in its own way (for Windows) but I’d rather use Eclipse your choice.

Please feel free to be a part of the project. Warning us of any bugs will be rewarded with a Cookie.

Now back to the BeagleBoard was indeed a great buy. Small and fast. Though the peripherals cost us quite much. We installed Angstrom Linux  distribution. Which could be found at http://www.angstrom-distribution.org/ . Being new in using the BeagleBoard we decided to use some of the sources at hand. We started with the site http://elinux.org/BeagleBoardBeginners . We ran into some problems.

Our first problem was that we did not have a AT-Everex cable to connect to the board. So we had to jump to Step 5 of the steps presented in the web-site.  Which is basicly Linux Boot Formatting the SDHC disc we bought for the board. I beg you please not to follow the steps at elinux.org instead follow http://code.google.com/p/beagleboard/wiki/LinuxBootDiskFormat . It is much more clear and you don’t get side stepped. Once we used the steps in formatting the SD disk in code.google.com we noticed we needed cable so we can tell the board where to boot from. So until we get that cable (or make one for our selves?) the project is at a halt. Just follow this blog for any more updates on the board and follow the Sourceforge.net ‘s for the changes on our code.

Peace!

Up here you can see a hacker can sniff the client-server connection and actually steal the user name and password sent by client. This really won’t do since if someone can spoof/hack/attack our embedded system which we will be adding to home appliances things may go awry. i.e. you will start seeing automated vacuum cleaners attacking your cat. ( Statistics show that H4X0Rz hate cats. )

Hence we can clearly see we need another way for the server and client to talk to each other. After some short Googling I am thinking of using SSH which is native to Linux/Unix based systems. Where the connection will be as below ;

As you can see the SSH encryption creates a safer environment for the client and the server plus any DNS attacks and eavesdropping is clearly impossible. (if not probable.)

Henceforth a new PHP and Python (this time I will write the server+client in Python) shall be written. Please expect updates.

import java.io.*;
import java.net.*;

//This program will listen to port 8189

public class ThreadedEchoServer{

 public static void main (String[] args){

 try{

 int i =1;
 ServerSocket s = new ServerSocket(8189);

 for (;;)
 {  
 Socket incoming = s.accept( );
 System.out.println("Spawning " + i);
 Thread t = new ThreadedEchoHandler(incoming, i);
 t.start();
 i++;
 }

 }catch (Exception e){

 e.printStackTrace();

 }

 }

}
/**
This class handles the client input for one server socket
connection.
*/
class ThreadedEchoHandler extends Thread
{
/**
 Constructs a handler.
 @param i the incoming socket
 @param c the counter for the handlers (used in prompts)
*/
public ThreadedEchoHandler(Socket i, int c)
{
 incoming = i; counter = c;
}

public void run()
{  
 try
 {  
 BufferedReader in = new BufferedReader
 (new InputStreamReader(incoming.getInputStream()));
 PrintWriter out = new PrintWriter
 (incoming.getOutputStream(), true /* autoFlush */);

 out.println( "Hello! Enter BYE to exit." );

 boolean done = false;
 while (!done)
 {  
 String str = in.readLine();
 if (str == null) done = true;
 else
 {  
 // out.println("Echo (" + counter + "): " + str);
 out.println("Connected to : " + str + "<br/>");
 //this is where you get the dang str!!! that is sent by embedded  device.
 //OR this is where you get the configurations from php server on the embedded device.
 System.out.println("Php server sent the following string :"+str);

 if (str.trim().equals("BYE"))
 done = true;
 }
 }
 incoming.close();
 }
 catch (Exception e)
 {  
 e.printStackTrace();
 }
}

private Socket incoming;
private int counter;
}

So we have finished with the Java code. Which both can be installed in the server or the embedded device. Notice that the port is  8189. Let us assume that this nice piece of work is on the embedded device. Now we have to send commands to and from the device via PHP using a telnet like protocol. That is when I started searching Google. Came up with a nice site http://www.geckotribe.com/php-telnet/

A nice site if you want to send data to and from telnet. And indeed it was what I needed. However I needed to do some modifications to the code they provided. The code below belongs to them;

(PHPTelnet.php)

<?php
/*
PHPTelnet
*/

class PHPTelnet {
 var $show_connect_error=1;

 var $use_usleep=1;    // change to 1 for faster execution default:0
 // don't change to 1 on Windows servers unless you have PHP 5
 var $sleeptime=125000;
 var $loginsleeptime=1000000;

 var $fp=NULL;
 var $loginprompt;

 var $conn1;
 var $conn2;

 /*
 0 = success
 1 = couldn't open network connection
 2 = unknown host
 3 = login failed
 4 = PHP version too low
 */
 function Connect($server,$user,$pass) {
 $rv=0;
 $vers=explode('.',PHP_VERSION);
 $needvers=array(4,3,0);
 $j=count($vers);
 $k=count($needvers);
 if ($k<$j) $j=$k;
 for ($i=0;$i<$j;$i++) {
 if (($vers[$i]+0)>$needvers[$i]) break;
 if (($vers[$i]+0)<$needvers[$i]) {
 $this->ConnectError(4);
 return 4;
 }
 }

 $this->Disconnect();

 if (strlen($server)) {
 if (preg_match('/[^0-9.]/',$server)) {
 $ip=gethostbyname($server);
 if ($ip==$server) {
 $ip='';
 $rv=2;
 }
 } else $ip=$server;
 } else $ip='127.0.0.1';

 if (strlen($ip)) {
 if ($this->fp=fsockopen($ip,8189))
 {

 if( ($user!="")&& ($pass!=""))
 {
 fputs($this->fp,$this->conn1);
 $this->Sleep();

 fputs($this->fp,$this->conn2);
 $this->Sleep();
 $this->GetResponse($r);
 $r=explode("\n",$r);
 $this->loginprompt=$r[count($r)-1];

 fputs($this->fp,"$user\r");
 $this->Sleep();

 fputs($this->fp,"$pass\r");
 if ($this->use_usleep) usleep($this->loginsleeptime);
 else sleep(1);
 $this->GetResponse($r);
 $r=explode("\n",$r);
 if (($r[count($r)-1]=='')||($this->loginprompt==$r[count($r)-1])) {
 $rv=3;
 $this->Disconnect();
 }

 }
 } else $rv=1;
 }

 if ($rv) $this->ConnectError($rv);
 return $rv;
 }

 function Disconnect($exit=1) {
 if ($this->fp) {
 if ($exit) $this->DoCommand('exit',$junk);
 fclose($this->fp);
 $this->fp=NULL;
 }
 }

 function DoCommand($c,&$r) {
 if ($this->fp) {
 fputs($this->fp,"$c\r");
 $this->Sleep();
 $this->GetResponse($r);
 $r=preg_replace("/^.*?\n(.*)\n[^\n]*$/","$1",$r);
 }
 return $this->fp?1:0;
 }

 function GetResponse(&$r) {
 $r='';
 do {
 $r.=fread($this->fp,1000);
 $s=socket_get_status($this->fp);
 } while ($s['unread_bytes']);
 }

 function Sleep() {
 if ($this->use_usleep) usleep($this->sleeptime);
 else sleep(1);
 }

 function PHPTelnet() {
 $this->conn1=chr(0xFF).chr(0xFB).chr(0x1F).chr(0xFF).chr(0xFB).
 chr(0x20).chr(0xFF).chr(0xFB).chr(0x18).chr(0xFF).chr(0xFB).
 chr(0x27).chr(0xFF).chr(0xFD).chr(0x01).chr(0xFF).chr(0xFB).
 chr(0x03).chr(0xFF).chr(0xFD).chr(0x03).chr(0xFF).chr(0xFC).
 chr(0x23).chr(0xFF).chr(0xFC).chr(0x24).chr(0xFF).chr(0xFA).
 chr(0x1F).chr(0x00).chr(0x50).chr(0x00).chr(0x18).chr(0xFF).
 chr(0xF0).chr(0xFF).chr(0xFA).chr(0x20).chr(0x00).chr(0x33).
 chr(0x38).chr(0x34).chr(0x30).chr(0x30).chr(0x2C).chr(0x33).
 chr(0x38).chr(0x34).chr(0x30).chr(0x30).chr(0xFF).chr(0xF0).
 chr(0xFF).chr(0xFA).chr(0x27).chr(0x00).chr(0xFF).chr(0xF0).
 chr(0xFF).chr(0xFA).chr(0x18).chr(0x00).chr(0x58).chr(0x54).
 chr(0x45).chr(0x52).chr(0x4D).chr(0xFF).chr(0xF0);
 $this->conn2=chr(0xFF).chr(0xFC).chr(0x01).chr(0xFF).chr(0xFC).
 chr(0x22).chr(0xFF).chr(0xFE).chr(0x05).chr(0xFF).chr(0xFC).chr(0x21);
 }

 function ConnectError($num) {
 if ($this->show_connect_error) switch ($num) {
 case 1: echo '<br />[PHP Telnet] <a href="http://www.geckotribe.com/php-telnet/errors/fsockopen.php">Connect failed: Unable to open network connection</a><br />'; break;
 case 2: echo '<br />[PHP Telnet] <a href="http://www.geckotribe.com/php-telnet/errors/unknown-host.php">Connect failed: Unknown host</a><br />'; break;
 case 3: echo '<br />[PHP Telnet] <a href="http://www.geckotribe.com/php-telnet/errors/login.php">Connect failed: Login failed</a><br />'; break;
 case 4: echo '<br />[PHP Telnet] <a href="http://www.geckotribe.com/php-telnet/errors/php-version.php">Connect failed: Your server\'s PHP version is too low for PHP Telnet</a><br />'; break;
 }
 }
}

return;
?>

However because I needed something that used a different port had to change the port number if you look at the comments in the form you will see where I edited the code.

Also because my Telnet was without a password ( i wanted to test it first) I added an “if” statement. Now to the index.php code;

<html><head><title></title></head><body>

<?php

require_once "PHPTelnet.php";

$telnet = new PHPTelnet();

// if the first argument to Connect is blank,
// PHPTelnet will connect to the local host via 127.0.0.1
// the second blank is for the username (may be for embedded device)
// the third blank is for the password (may be for embedded device)
$result = $telnet->Connect('','','');

if ($result == 0) {
$telnet->DoCommand('The embedded device!!', $result);
// NOTE: $result may contain newlines
echo $result;
$telnet->DoCommand('BYE', $result);
echo $result;
// say Disconnect(0); to break the connection without explicitly logging out
$telnet->Disconnect();
}

?>
</body></html>

Now to run a test; first run the Java program ( I hope you know how to compile and run a java program from console.) And than simply open index.php ( of course from Apache! ) And voilà!! you have a program that can connect directly to a php server page!!

Questions? Comments just send it in!