Bits By The Pound

2014
12.29

Creating a time-lapse movie using avconv

Author: jpfiset / Category: General / Tags: no tag / 2 comments

This note explains how to take a number of still images and combine them into a movie using “avconv”.

This note applies to:

Ubuntu 14.04
avconv 9.16

Planning

Before starting a time-lapse project, one should consider some constraints. The number of pictures that can be taken by the camera is constrained by the size of the memory card where the camera saves its information. On the other hand, the largest possible number of pictures should be taken, since it provides for a smoother end video.

Therefore, an approximate length of the event to be recorded must be used, in conjunction with the total number of pictures that can be saved to memory, to compute the interval between each picture taken.

Also, one should consider the power needs for the extended duration that the camera is used.

Finally, the memory card used by the camera should be fast enough to record the images at the rate that they will be produced.

Image collection

After all pictures have been taken, one ends up with a large collection of images, generally numbered sequentially by the camera using a special naming convention. For this note, an example is used to demonstrate the process. In this example, about 2300 pictures were taken every two seconds, over a period of 1 hour and 20 minutes. The resulting collection was picture named as follows:

IMG_6796.JPG
IMG_6797.JPG
IMG_6798.JPG
IMG_6799.JPG
IMG_6800.JPG
IMG_6801.JPG
IMG_6802.JPG
IMG_6803.JPG
IMG_6804.JPG
...
IMG_9170.JPG
IMG_9171.JPG
IMG_9172.JPG
IMG_9173.JPG

IMG_6796.JPG

IMG_6797.JPG

IMG_6798.JPG

IMG_6799.JPG

IMG_6800.JPG

IMG_6801.JPG

IMG_6802.JPG

IMG_6803.JPG

IMG_6804.JPG

...

IMG_9170.JPG

IMG_9171.JPG

IMG_9172.JPG

IMG_9173.JPG

Creating Movie

On Ubuntu, the command-line tool “avconv” can be used to combines still images into a movie. The command required to combine the images from the previous example is:

avconv -r 10 -start_number 6796 -i IMG_%d.JPG -q:v 0 -s hd1080 -vcodec libx264 -crf 25 movie.mp4

1	avconv -r 10 -start_number 6796 -i IMG_%d.JPG -q:v 0 -s hd1080 -vcodec libx264 -crf 25 movie.mp4

The parameter “-r 10” sets the number of frames per second on the input stream. This is an important parameter since it influences both the smoothness of the video and its length. The higher the number, the smoother the resulting video. Ideally, the input frame rate should be 25 to 30 frames per seconds for the best smoothness.

However, following our example, at 25 frames per second, the resulting video would be 1.5 minutes long. In our example, we wish to have the resulting movie showing the original event over 4 minutes. Therefore, the input rate is set to 10.

The parameter “-start_number 6796” specifies the number at which the file name sequence starts at. This parameter is used with the input file format parameter “-i IMG_%d.JPG”, where the portion of the name with %d is replaced by a number, to find each image file.

The parameter “-q:v 0” sets the highest output video quality.

The parameter “-s hd1080” is used to sets the output dimensions of the video to high definition.

The parameters “-vcodec libx264” and “-crf 25” are used to set the output CODEC to H.264 and output frame rate. The output frame rate does not affect the length of the movie.

Conclusion

Although there are many factors to consider when making a time-lapse movie, the command-line tool “avconv” is really useful stitch together the video portion of the project. “avconv” is the successor to “ffmpeg”. Both tools are mature and contain a large number of options.

Therefore, use the options above as a starting point and experiment until you reach the desired effect.

2014
09.12

Access WebDAV drive over SSL using Basic Auth via Windows 7

Author: jpfiset / Category: General / Tags: no tag / Add Comment

This note explains how to use a WebDAV drive using Windows 7. In particular, this note addresses issues that arise when the WebDAV drive enforces SSL, using a self-signed certificate, and basic authentication. All the steps detailed below are performed on a Windows 7 computer where the Web drive is intended to be used.

This note relates to:

Windows 7 client
WebDAV drive served by Apache 2.2

References:

Adjust Registry

This step is required if the WebDAV drive enforces user authentication using HTTP “Basic Auth”.

Start the program “regedit.exe” using the following steps:

Press “Start” button
Choose “Run”
Enter “regedit.exe” and press enter

In the regedit program, navigate down the tree using the following path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WebClient\Parameters

Within the “Parameters” section, set the value of setting “BasicAuthLevel” to 2. The meaning of the values are:

0 – Basic authentication disabled
1 – Basic authentication enabled for SSL shares only
2 or greater – Basic authentication enabled for SSL shares and for non-SSL shares

Close the regedit program.

Reboot Windows.

Import Self-Signed Certificate

This steps imports the WebDAV certificate to the store of trusted certificate. This step is necessary only if the certificate
is self-signed.

Open Internet Explorer as an administrator. Only IE will work for this step (Firefox and Chrome are not helping for this situation).
To open IE as an administrator, press on the “Start” button and find the Internet Explorer entry. Right click on the Internet Explorer entry in the start menu and choose “Run as administrator”.

In IE, browse to the site where the WebDAV is stored. It should be a URL that looks like “https://www.mycompany.com/dav/”. If the certificate has not been previously accepted, a dialogue box opens warning the user that the certificate is not trusted. Choose to “Continue to this website (not recommended)”.
Once the page of the WebDAV is displayed, the address bar will contain a tab titled “Certificate Error”. Click on this tab and choose “View Certificates”.
Click on the “Install Certificate…” button.
Choose the option â€œPlace all certificates in the following storeâ€ and click on the “Browse…” button
Select “Trusted Root Certification Authorities” folder and press “OK” button
Click on “Next” and then “Finish”
Accept warnings

Once the certificate is installed, IE can be dismissed since it is no longer used.

Mount WedDAV drive

Mount the WebDAV drive using the following steps:

Start Windows Explorer (Start > All Programs > Accessories > Windows Explorer)
Right-click on “Computer” icon and select “Map Network Drive”
Select a letter for your drive
Enter the URL for the WebDAV drive (https://www.mycompany.com/dav/) in the field titled “Folder”
Select “Connect using different credentials”
Press “Finish” button
Enter user name and password

At this point, the WebDAV drive should be accessible like any other drive.

2014
01.28

Send message with SSL or STARTTLS using Java Mail

Author: jpfiset / Category: Java / Tags: no tag / 1 comment

This note explains how to send an e-mail message using JavaMail, including using an SSL connection or the STARTTLS built-in security.

This note applies to:

Java version 1.7
JavaMail version 1.4.1

If using Maven, the JavaMail artifact can be obtained using the following dependency:

<dependency>
	<groupId>com.sun.mail</groupId>
	<artifactId>javax.mail</artifactId>
	<version>${mail.version}</version>
</dependency>

<artifactId>javax.mail</artifactId>

<version>${mail.version}</version>

</dependency>

Often, a properties file is loaded to configure the SMTP transport layer. This allows a user to configure outgoing mail server without having to change the code. Here is a code excerpt to obtain a session and

	import javax.mail.Authenticator;
	import javax.mail.Message;
	import javax.mail.Multipart;
	import javax.mail.PasswordAuthentication;
	import javax.mail.Session;
	import javax.mail.Transport;

	public void send(String to, String from, Properties mailProperties) throws Exception {

		// Check for user name and password
		String userName = null;
		String userPassword = null;
		String prot = mailProperties.getProperty("mail.transport.protocol",null);
		if( null != prot ){
			userName = mailProperties.getProperty("mail."+prot+".user",null);
			userPassword = mailProperties.getProperty("mail."+prot+".password",null);
		}
		
		// Create session
		Session mailSession = null;
		if( null != userName && null != userPassword ) {
			final String name = userName;
			final String pw = userPassword;
			
			Authenticator auth = new Authenticator(){
				protected PasswordAuthentication getPasswordAuthentication() {
					return new PasswordAuthentication(name,pw);
				}
			};
			mailSession = Session.getInstance(mailProperties, auth);
		} else {
			mailSession = Session.getInstance(mailProperties);
		}
		
		// Create a default MimeMessage object.
		MimeMessage message = new MimeMessage(mailSession);
		
		// Set "from" address
		message.setFrom(new InternetAddress(from));
		
		// Set "to" address
		message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
		
		// Subject
		message.setSubject("Hello");
		
		// Body
		message.setText("Hello World");
		
		// Send message
		Transport.send(message);	
	}

import javax.mail.Authenticator;

import javax.mail.Message;

import javax.mail.Multipart;

import javax.mail.PasswordAuthentication;

import javax.mail.Session;

import javax.mail.Transport;

public void send(String to, String from, Properties mailProperties) throws Exception {

// Check for user name and password

String userName = null;

String userPassword = null;

String prot = mailProperties.getProperty("mail.transport.protocol",null);

if( null != prot ){

userName = mailProperties.getProperty("mail."+prot+".user",null);

userPassword = mailProperties.getProperty("mail."+prot+".password",null);

}

// Create session

Session mailSession = null;

if( null != userName && null != userPassword ) {

final String name = userName;

final String pw = userPassword;

Authenticator auth = new Authenticator(){

protected PasswordAuthentication getPasswordAuthentication() {

return new PasswordAuthentication(name,pw);

}

};

mailSession = Session.getInstance(mailProperties, auth);

} else {

mailSession = Session.getInstance(mailProperties);

}

// Create a default MimeMessage object.

MimeMessage message = new MimeMessage(mailSession);

// Set "from" address

message.setFrom(new InternetAddress(from));

// Set "to" address

message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));

// Subject

message.setSubject("Hello");

// Body

message.setText("Hello World");

// Send message

Transport.send(message);

}

Plain Text

For plain text access to the SMTP service, the following properties can be used:

mail.transport.protocol=smtp
mail.smtp.host=<host>
mail.smtp.port=25
mail.smtp.auth=true
mail.smtp.user=<username>
mail.smtp.password=<password>

mail.transport.protocol=smtp

mail.smtp.host=<host>

mail.smtp.port=25

mail.smtp.auth=true

mail.smtp.user=<username>

mail.smtp.password=<password>

STARTTLS

For sending a message using the STARTTLS built-in security, the following properties should be used:

mail.transport.protocol=smtp
mail.smtp.host=<host>
mail.smtp.port=587
mail.smtp.auth=true
mail.smtp.user=<username>
mail.smtp.password=<password>
mail.smtp.starttls.enable=true

mail.transport.protocol=smtp

mail.smtp.host=<host>

mail.smtp.port=587

mail.smtp.auth=true

mail.smtp.user=<username>

mail.smtp.password=<password>

mail.smtp.starttls.enable=true

SSL

For sending a message using SMTP over SSL, the following properties should be used:

mail.transport.protocol=smtp
mail.smtp.host=<host>
mail.smtp.port=465
mail.smtp.auth=true
mail.smtp.user=<username>
mail.smtp.password=<password>
mail.smtp.socketFactory.port=465
mail.smtp.socketFactory.class=javax.net.ssl.SSLSocketFactory

mail.transport.protocol=smtp

mail.smtp.host=<host>

mail.smtp.port=465

mail.smtp.auth=true

mail.smtp.user=<username>

mail.smtp.password=<password>

mail.smtp.socketFactory.port=465

mail.smtp.socketFactory.class=javax.net.ssl.SSLSocketFactory

Debugging

There is a property which sets the “debug” mode for JavaMail. It can be set with the following properties:

mail.debug=true

1	mail.debug=true

2013
02.10

Setup development environment for EZ430-F2013 using Eclipse in Ubuntu

Author: jpfiset / Category: General / Tags: no tag / 1 comment

This note explains how to set up Eclipse for developing images for the EZ430-F2013. This note assumes that the development environment is set up in Ubuntu 12.10.

This note relates to:

Ubuntu 12.10
EZ430-F2013
msp430-gcc version 4.6.3
Eclipse Classic version 4.2.1

References:

Install Command-Line Tools

The installation of command-line tools to support the EZ430-F2013 development kit is covered in a different note. Please refer to the note Use EZ430-F2013 in Ubuntu to complete this step.

Install CDT

In Eclipse, the packages that support C/C++ development are named the C Development Toolkit, or CDT. Portions of the CDT are required to enabled a development environment for the EZ430-F2013:

C/C++ Development Tools
C/C++ Development Tools SDK
C/C++ Debugger Services Framework (DSF) Examples
C/C++ GDB Hardware Debugging

To install the CDT, in Eclipse:

Help > Install New Software…
Add a repository. Name: Eclipse CDT. Location: http://download.eclipse.org/tools/cdt/releases/juno
Select the packages mentioned above.

Create a C project to use MSP-GCC

Create a C project:

“File” > “New” > “Project…” > “C/C++ / C Project”
Enter a project name
Use default location
Project Type: Executable > Empty Project > Linux GCC
Press Finish

Set up new project to use MSP-GCC:

Right-click on project, select “Properties”
Select page “C/C++ Build” > “Settings”
Select configuration “[ All configurations ]”
Select settings “Tool Settings” > “GCC C Compiler”
- Command: msp430-gcc -mmcu=msp430f2013
Select settings “Tool Settings” > “GCC C Compiler” > “Includes”
- Add include path: /usr/msp430/include
Select settings “Tool Settings” > “GCC C Compiler” > “Optimization”
- Optimization Level: “Optimize for size (-Os)”
Select settings “Tool Settings” > “GCC C Linker”
- Command: msp430-gcc -mmcu=msp430f2013 -Wl,-Map=${BuildArtifactFileBaseName}.map
Select settings “Tool Settings” > “GCC C Linker” > “Libraries”
- Add library search path: /usr/msp430/lib
Select settings “Tool Settings” > “GCC Assembler”
- Command: msp430-as
Select settings “Tool Settings” > “GCC Assembler” > “General”
- Add include path: /usr/msp430/include
Select settings “Build Artifact”
- Artifact type: “Executable”
- Artifact extension: “elf”
Select settings “Binary Parsers”
- select “Elf Parser”
Press “Apply” and “OK”

Once the project is set up correctly, it should be possible to build an image from source by right-clicking on the project and selecting “Build Project”. In the console, the output of the build should look something like the following:

00:00:00 **** Build of configuration Debug for project XXX ****
make all 
Building file: ../main.c
Invoking: GCC C Compiler
msp430-gcc -mmcu=msp430f2013 -I/usr/msp430/include -Os -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o "main.o" "../main.c"
Finished building: ../main.c
 
Building target: xxx.elf
Invoking: GCC C Linker
msp430-gcc -mmcu=msp430f2013 -Wl,-Map=xxx.map -L/usr/msp430/lib -o "xxx.elf"  ./main.o   
Finished building target: xxx.elf

00:00:00 Build Finished (took 166ms)

00:00:00 **** Build of configuration Debug for project XXX ****

make all

Building file: ../main.c

Invoking: GCC C Compiler

msp430-gcc -mmcu=msp430f2013 -I/usr/msp430/include -Os -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o "main.o" "../main.c"

Finished building: ../main.c

Building target: xxx.elf

Invoking: GCC C Linker

msp430-gcc -mmcu=msp430f2013 -Wl,-Map=xxx.map -L/usr/msp430/lib -o "xxx.elf" ./main.o

Finished building target: xxx.elf

00:00:00 Build Finished (took 166ms)

Set Up Debugger Configuration

To debug the project directly from the IDE, a debugger must be configured. The following steps are used to configure a debugger to use the command-line tool “msp430-gdb”:

Select “Run” > “Debug Configuration…”
Select “GDB Hardware Debugging”
Press the “New” icon
Set name
Tab “Main”:
- Project: select project
Tab “Debugger”:
- GDB Command: msp430-gdb
- Set “Use remote target”
- JTAG Device: Generic TCP/IP
- Host name or IP address: localhost
- Port number: 2000
Tab “Startup”:
- Reset and Delay: 3
- Set: “Halt”
- Initialization Commands: “monitor erase”
- Set: “Load image”
- Set: “Use project binary”
- Set: “Load symbols”
- Set: “Use project binary”
Tab “Common”:
- Save as: “Shared file” (select project)
- Display in favorite menu: “Debug”
Press “Apply”

Running the debugger from the IDE is the equivalent to running “msp430-gdb” at the command-line. It first requires that “mspdebug” runs to bridge to the EZ430-F2013 development kit. This can be perform from a terminal or from an Eclipse run configuration (next section).

To run the debugger, select from the menu “Run” > “Debug Configurations…”, choose the debugger create and press the button “Debug”.

Run MSPDEBUG from Eclipse

It is possible to run “mspdebug” from Eclipse using a run configuration. Here are the steps to set it up:

Select “Run” > “External Tools” > “External Tools Configurations…”
Right-click on “Program” and select “New”
Enter name: MSPDebug
Select “Main” tab:
- Location: /usr/bin/mspdebug
- Arguments: uif -d /dev/ttyUSB0 gdb

Once set up as an external tool, to run “mspdebug”, select “Run” > “External Tools” > “External Tools Configurations…”, click on the program called “MSPDebug” and press the “Run” button.

Conclusion

There are many short-cuts in Eclipse to run external tools and debug configurations without using the tedious menus. One of these short-cuts are located on the main tool bar. These short-cuts makes it very convenient to start “mspdebug” and “msp430-gdb”. The ability of developing and debugging using the EZ430-F2013 directly from Eclipse greatly reduces the development cycle of an image targeted for the MSP430.

2013
02.09

Use EZ430-F2013 in Ubuntu

Author: jpfiset / Category: General / Tags: no tag / 5 comments

This note explains how to install the command-line tools in Ubuntu to compile, load and run images destined for the Texas Instrument EZ430-F2013.

The TI EZ430-F2013 is a USB development environment for small dongles that host a TI MSP430 micro-controller (MSP430-F2012 and MSP430-F2013).

This note relates to:

TI EZ430-F2013
Ubuntu 12.10
msp430-gcc version 4.6.3

Install Packages

The packages required to work with the MSP430 are available from the main repositories.

sudo apt-get install binutils-msp430 gcc-msp430 gdb-msp430 msp430-libc msp430mcu mspdebug

1	sudo apt-get install binutils-msp430 gcc-msp430 gdb-msp430 msp430-libc msp430mcu mspdebug

Verify Drivers for EZ430-F2013

Insert the EZ430-F2013 in a USB port. Then, run “dmesg” to verify that it was detected correctly:

dmesg

dmesg

The output should end with a set of lines that looks as follows:

[47661.708176] usb 5-1: new full-speed USB device number 8 using uhci_hcd
[47661.905243] usb 5-1: New USB device found, idVendor=0451, idProduct=f430
[47661.905253] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[47661.905260] usb 5-1: Product: MSP-FET430UIF JTAG Tool
[47661.905266] usb 5-1: Manufacturer: Texas Instruments
[47661.905272] usb 5-1: SerialNumber: TUSB3410572A43E3DB45FFB1
[47661.909238] ti_usb_3410_5052 5-1:1.0: TI USB 3410 1 port adapter converter detected
[47662.492172] usb 5-1: reset full-speed USB device number 8 using uhci_hcd
[47662.636193] usb 5-1: device firmware changed
[47662.636240] ti_usb_3410_5052: probe of 5-1:1.0 failed with error -5
[47662.636365] usb 5-1: USB disconnect, device number 8
[47662.804100] usb 5-1: new full-speed USB device number 9 using uhci_hcd
[47663.029224] usb 5-1: New USB device found, idVendor=0451, idProduct=f430
[47663.029233] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[47663.029240] usb 5-1: Product: MSP-FET430UIF JTAG Tool
[47663.029246] usb 5-1: Manufacturer: Texas Instruments
[47663.029252] usb 5-1: SerialNumber: TUSB3410572A43E3DB45FFB1
[47663.032921] ti_usb_3410_5052 5-1:1.0: TI USB 3410 1 port adapter converter detected
[47663.032950] ti_usb_3410_5052: probe of 5-1:1.0 failed with error -5
[47663.037227] ti_usb_3410_5052 5-1:2.0: TI USB 3410 1 port adapter converter detected
[47663.037509] usb 5-1: TI USB 3410 1 port adapter converter now attached to ttyUSB0

[47661.708176] usb 5-1: new full-speed USB device number 8 using uhci_hcd

[47661.905243] usb 5-1: New USB device found, idVendor=0451, idProduct=f430

[47661.905253] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3

[47661.905260] usb 5-1: Product: MSP-FET430UIF JTAG Tool

[47661.905266] usb 5-1: Manufacturer: Texas Instruments

[47661.905272] usb 5-1: SerialNumber: TUSB3410572A43E3DB45FFB1

[47661.909238] ti_usb_3410_5052 5-1:1.0: TI USB 3410 1 port adapter converter detected

[47662.492172] usb 5-1: reset full-speed USB device number 8 using uhci_hcd

[47662.636193] usb 5-1: device firmware changed

[47662.636240] ti_usb_3410_5052: probe of 5-1:1.0 failed with error -5

[47662.636365] usb 5-1: USB disconnect, device number 8

[47662.804100] usb 5-1: new full-speed USB device number 9 using uhci_hcd

[47663.029224] usb 5-1: New USB device found, idVendor=0451, idProduct=f430

[47663.029233] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3

[47663.029240] usb 5-1: Product: MSP-FET430UIF JTAG Tool

[47663.029246] usb 5-1: Manufacturer: Texas Instruments

[47663.029252] usb 5-1: SerialNumber: TUSB3410572A43E3DB45FFB1

[47663.032921] ti_usb_3410_5052 5-1:1.0: TI USB 3410 1 port adapter converter detected

[47663.032950] ti_usb_3410_5052: probe of 5-1:1.0 failed with error -5

[47663.037227] ti_usb_3410_5052 5-1:2.0: TI USB 3410 1 port adapter converter detected

[47663.037509] usb 5-1: TI USB 3410 1 port adapter converter now attached to ttyUSB0

The report from “dmesg” shows that the development kit was mounted to /dev/ttyUSB0. For the remainder of the note, this value is assumed. However, you might need to adjust this value to fit your particular installation.

ls /dev/ttyUSB*

1	ls /dev/ttyUSB*

Writing a program for MSP430-F2013

Create a new source file.

gedit sos.c

1	gedit sos.c

Paste the following code:

#include <msp430f2013.h>

#define DIM(x) (sizeof(x)/sizeof(x[0]))
#define DOT  {10000, 1}
#define DASH {30000, 1}
#define SP   { 8000, 0}
#define LTR  {16000, 0}
#define WRD  {80000, 0}

#define MORSE_S DOT,SP,DOT,SP,DOT,LTR
#define MORSE_O DASH,SP,DASH,SP,DASH,LTR

typedef struct _Segment {
	unsigned long delay;
	unsigned char state;
} Segment;

Segment segments[] = {
		MORSE_S
		,MORSE_O
		,MORSE_S
		,WRD
};

int main(void)
{
	WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog timer
	P1DIR |= 0x01;                            // Set P1.0 to output direction

	int sequence = 0;

	for (;;)
	{
		volatile unsigned long i;

		Segment segment = segments[sequence];

		if( segment.state ) {
			P1OUT |= 0x01; // Turn on LED
		} else {
			P1OUT &= 0xfe; // Turn off LED
		}

		i = segment.delay; // Delay
		do (i--);
		while (i != 0);

		// Go to next segment
		++sequence;
		if( sequence >= DIM(segments) ){
			sequence = 0;
		}
	}

	return 0;
}

#include <msp430f2013.h>

#define DIM(x) (sizeof(x)/sizeof(x[0]))

#define DOT {10000, 1}

#define DASH {30000, 1}

#define SP { 8000, 0}

#define LTR {16000, 0}

#define WRD {80000, 0}

#define MORSE_S DOT,SP,DOT,SP,DOT,LTR

#define MORSE_O DASH,SP,DASH,SP,DASH,LTR

typedef struct _Segment {

unsigned long delay;

unsigned char state;

} Segment;

Segment segments[] = {

MORSE_S

,MORSE_O

,MORSE_S

,WRD

};

int main(void)

{

WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer

P1DIR |= 0x01; // Set P1.0 to output direction

int sequence = 0;

for (;;)

{

volatile unsigned long i;

Segment segment = segments[sequence];

if( segment.state ) {

P1OUT |= 0x01; // Turn on LED

} else {

P1OUT &= 0xfe; // Turn off LED

}

i = segment.delay; // Delay

do (i--);

while (i != 0);

// Go to next segment

++sequence;

if( sequence >= DIM(segments) ){

sequence = 0;

}

return 0;

}

The code above drives the LED found on the MSP430-F2013 to emit “SOS” in Morse code. A number of definitions are already declared in the file “msp430f2013.h”. Many header files relating to the MSP430 can be found in the directory /usr/msp430/include.

Compiling and Linking Program

Compiling and linking programs/images for the MSP430 is done by using “msp430-gcc”, which is a version of “gcc” that targets the MSP430 micro-controller. Most options available for “gcc” are also available for “msp430-gcc”.

Compiling using “msp430-gcc” yields object files, as with “gcc”. However, invoking the linker produces *.elf files, which can be loaded on the MSP430-F2013 via the development kit (EZ430-F2013).

Following the example started above, the two lines required to produce an object file from the source code, and then link into an image:

msp430-gcc -c -mmcu=msp430f2013 -g -Os -Wall -Wunused -IInclude -o sos.o sos.c
msp430-gcc sos.o -mmcu=msp430f2013 -Wl,-Map=sos.map  -o sos.elf

1 2	msp430-gcc -c -mmcu=msp430f2013 -g -Os -Wall -Wunused -IInclude -o sos.o sos.c msp430-gcc sos.o -mmcu=msp430f2013 -Wl,-Map=sos.map -o sos.elf

mspdebug

A command line utility called “mspdebug” is used to perform most operations that involves the EZ430-F2013 development kit.

First, insert the EZ430-F2013 in a USB port and verify that it is mounted to /dev/ttyUSB0 (see steps above).

When invoking “mspdebug”, one must specify the device that the EZ430-F2013 is mounted as.

mspdebug uif -d /dev/ttyUSB0

1	mspdebug uif -d /dev/ttyUSB0

This command opens a shell where a number of commands can be sent to the development kit. To leave the shell, press CTRL-D.

Loading Image on MSP430-F2013

Loading an image on an instance of MSP430-F2013 via the development kit is accomplished by using “mspdebug”:

mspdebug uif -d <device> "prog <elf-file>"

1	mspdebug uif -d <device> "prog <elf-file>"

where:

<device> refers to the device file name where the USB development kit is mounted
<elf-file> refers to the ELF file produce by the msp430-gcc linker

Following the example above:

mspdebug uif -d /dev/ttyUSB0 "prog sos.elf"

1	mspdebug uif -d /dev/ttyUSB0 "prog sos.elf"

Debugging MSP430

Via the EZ430-F2013, one can debug the program loaded in the MSP430, including single-step execution, via the “gdb” debugger provided by the MSP430 packages. The command-line utility “msp430-gdb” is similar to “gdb” but designed for the MSP430 micro-controller. However, “mspdebug” is needed to bridge “msp430-gdb” to the MSP430 via the EZ430-F2013 development kit.

The command “gdb” within the shell provided by “mspdebug” start a server that listens to commands from “msp430-gdb” and forwards them to the EZ430-F2013 development kit. When “msp430-gdb” connects to “mspdebug”, it provides a shell similar to the one provided by “gdb”.

The command required to start the server is:

mspdebug uif -d <device> gdb

1	mspdebug uif -d <device> gdb

In a different terminal, attach the debugger with the following command:

msp430-gdb <elf-file>

1	msp430-gdb <elf-file>

The commands available in “gdb” are also available in “msp430-gdb”:

To execute program: continue
To stop program: CTRL-C
To list stack variables: info locals
To list global variables: info variables

To continue the example started above:

mspdebug uif -d /dev/ttyUSB0 gdb &
msp430-gdb sos.elf

1 2	mspdebug uif -d /dev/ttyUSB0 gdb & msp430-gdb sos.elf

Debug using X Debugger: ddd

If X is available, one can use “ddd”, which is a GUI application to simplify the use of gdb.

sudo apt-get install ddd

1	sudo apt-get install ddd

To use “msp430-gdb” via “ddd”, one must first start “mspdebug” and then invoke “ddd” by specifying “msp430-gdb”. To continue the example in this note:

mspdebug uif -d /dev/ttyUSB0 gdb &
ddd --debugger msp430-gdb sos.elf

1 2	mspdebug uif -d /dev/ttyUSB0 gdb & ddd --debugger msp430-gdb sos.elf

Conclusion

Using the TI EZ430-F2013 development kit with an Ubuntu platform is a snap since all the tools required are readily available in the main repositories. Furthermore, anyone familiar with gcc and gdb can easily transition to the line of tools designed for the MSP430 since the commands and options are almost the same.

2012
08.13

Fix magic for MP4 MSNV in Ubuntu 12.04

Author: jpfiset / Category: General / Tags: no tag / Add Comment

In Ubuntu, as in other flavours of Linux, utilities like “file” detect the type of files by using an algorithm based on “magic numbers”. This algorithm looks for fixed fields in the examined file. Lately, some of these utilities have failed in detecting the proper type for some encountered MP-4 files which do not contain the “magic numbers” expected of a MP-4 file.

This note presents a method to update the magic files to detect new file formats. More specifically, the method concentrates on updating the magic files to recognize the new MP-4 format.

This note relates to:

Ubuntu 10.04
Ubuntu 12.04
MP-4 format, major brand MSNV

References:

This note uses a number of examples to illustrate the fix. In these examples, two files are used, a MP-4 file recognized by the file utility named “known.mp4”; and, a MP-4 file not recognized by the utility named “unrecognized.mp4”.

Exploring the problem

For the recognized file, the following sequence is experienced:

file -bnr --mime known.mp4

1	file -bnr --mime known.mp4

video/mp4; charset=binary

1	video/mp4; charset=binary

As seen above, the format of the file is recognized correctly and the mime-type is return appropriately. Here is the sequence for the file which is not recognized correctly.

file -bnr --mime unrecognized.mp4

1	file -bnr --mime unrecognized.mp4

application/octet-stream; charset=binary

1	application/octet-stream; charset=binary

In the case of the file which is not recognized, a generic mime-type is returned.

Differences between files

Programs from the FFMPEG or libav projects can be used to find out details of video files. Using avprobe (or ffprobe), it is possible to get details from each file and examined the differences.

avprobe known.mp4

1	avprobe known.mp4

avprobe version 0.8.3-4:0.8.3-0ubuntu0.12.04.1, Copyright (c) 2007-2012 the Libav developers
  built on Jun 12 2012 16:37:58 with gcc 4.6.3
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'gwichin/media/conv391580280152567226.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 1970-01-01 00:00:00
    date            : 2012-03-06T15:55:04-0500
    encoder         : Lavf53.3.0
  Duration: 00:00:10.14, start: 0.000000, bitrate: 184 kb/s
    Stream #0.0(und): Video: h264 (High), yuv420p, 320x240, 132 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc
    Metadata:
      creation_time   : 1970-01-01 00:00:00
    Stream #0.1(und): Audio: aac, 44100 Hz, stereo, s16, 46 kb/s
    Metadata:
      creation_time   : 1970-01-01 00:00:00

built on Jun 12 2012 16:37:58 with gcc 4.6.3

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'gwichin/media/conv391580280152567226.mp4':

Metadata:

major_brand : isom

minor_version : 512

compatible_brands: isomiso2avc1mp41

creation_time : 1970-01-01 00:00:00

date : 2012-03-06T15:55:04-0500

encoder : Lavf53.3.0

Duration: 00:00:10.14, start: 0.000000, bitrate: 184 kb/s

Stream #0.0(und): Video: h264 (High), yuv420p, 320x240, 132 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc

Metadata:

creation_time : 1970-01-01 00:00:00

Stream #0.1(und): Audio: aac, 44100 Hz, stereo, s16, 46 kb/s

Metadata:

creation_time : 1970-01-01 00:00:00

avprobe unreconized.mp4

1	avprobe unreconized.mp4

avprobe version 0.8.3-4:0.8.3-0ubuntu0.12.04.1, Copyright (c) 2007-2012 the Libav developers
  built on Jun 12 2012 16:37:58 with gcc 4.6.3
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'upl5976181052131867323.mp4':
  Metadata:
    major_brand     : MSNV
    minor_version   : 19464262
    compatible_brands: MSNVmp42isom
    creation_time   : 2012-01-06 19:20:14
  Duration: 00:00:36.16, start: 0.000000, bitrate: 9614 kb/s
    Stream #0.0(jpn): Video: h264 (Main), yuv420p, 1280x720, 9490 kb/s, 30 fps, 30 tbr, 30k tbn, 60k tbc
    Metadata:
      creation_time   : 2012-01-06 19:20:14
    Stream #0.1(jpn): Audio: aac, 44100 Hz, mono, s16, 128 kb/s
    Metadata:
      creation_time   : 2012-01-06 19:20:14

built on Jun 12 2012 16:37:58 with gcc 4.6.3

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'upl5976181052131867323.mp4':

Metadata:

major_brand : MSNV

minor_version : 19464262

compatible_brands: MSNVmp42isom

creation_time : 2012-01-06 19:20:14

Duration: 00:00:36.16, start: 0.000000, bitrate: 9614 kb/s

Stream #0.0(jpn): Video: h264 (Main), yuv420p, 1280x720, 9490 kb/s, 30 fps, 30 tbr, 30k tbn, 60k tbc

Metadata:

creation_time : 2012-01-06 19:20:14

Stream #0.1(jpn): Audio: aac, 44100 Hz, mono, s16, 128 kb/s

Metadata:

creation_time : 2012-01-06 19:20:14

By looking at these reports, it becomes evident that although both files are reported as MP-4, they are not reporting the same major brand.

Detailed Differences

The “od” utility can be used to look at the byte information from each files. This information is necessary to craft the magic file needed to recognized the new format.

od -t x1 -t a known.mp4 | less

1	od -t x1 -t a known.mp4 \| less

0000000  00  00  00  20  66  74  79  70  69  73  6f  6d  00  00  02  00
        nul nul nul  sp   f   t   y   p   i   s   o   m nul nul stx nul
0000020  69  73  6f  6d  69  73  6f  32  61  76  63  31  6d  70  34  31
          i   s   o   m   i   s   o   2   a   v   c   1   m   p   4   1

0000000 00 00 00 20 66 74 79 70 69 73 6f 6d 00 00 02 00

nul nul nul sp f t y p i s o m nul nul stx nul

0000020 69 73 6f 6d 69 73 6f 32 61 76 63 31 6d 70 34 31

i s o m i s o 2 a v c 1 m p 4 1

A different file header is observed from the file that is not recognized:

od -t x1 -t a unrecognized.mp4 | less

1	od -t x1 -t a unrecognized.mp4 \| less

0000000  00  00  00  1c  66  74  79  70  4d  53  4e  56  01  29  00  46
        nul nul nul  fs   f   t   y   p   M   S   N   V soh   ) nul   F
0000020  4d  53  4e  56  6d  70  34  32  69  73  6f  6d  00  00  00  94
          M   S   N   V   m   p   4   2   i   s   o   m nul nul nul dc4

0000000 00 00 00 1c 66 74 79 70 4d 53 4e 56 01 29 00 46

nul nul nul fs f t y p M S N V soh ) nul F

0000020 4d 53 4e 56 6d 70 34 32 69 73 6f 6d 00 00 00 94

M S N V m p 4 2 i s o m nul nul nul dc4

In the case of the recognized file, the bytes detected are from offset 4 to 11, where “ftypisom” is recognized as belonging to a file of type MP-4. The same bytes in the file not recognized are “ftypMSNV”. The crafting of the magic numbers to recognize this new file type must be based on this latter string.

Updating Magic Numbers

This note does not explain the format of the magic number files. This topic is covered in other pages. See the references above.

In Ubuntu, updating the file /etc/magic with the proper entries is all that is required for the file utility to detect the new types. There is no need to compile the file, as in other versions of Linux. Nor is there a need to perform any reboot.

To edit the magic number file:

sudo gedit /etc/magic

1	sudo gedit /etc/magic

The following lines should be added to the magic file:

4       string  ftyp    ISO Media
>8      string  MSNV    \b, MPEG v4 system, version 2
!:mime  video/mp4

4 string ftyp ISO Media

>8 string MSNV \b, MPEG v4 system, version 2

!:mime video/mp4

After the magic number file is update, save and close.

Testing

To test that your changes are working, perform a “file” command on the previously not recognized video file:

> file unrecognized.mp4
upl5976181052131867323.mp4: ISO Media, MPEG v4 system, version 2
> file -bnr --mime unrecognized.mp4
video/mp4; charset=binary

> file unrecognized.mp4

upl5976181052131867323.mp4: ISO Media, MPEG v4 system, version 2

> file -bnr --mime unrecognized.mp4

video/mp4; charset=binary

If the results above are not observed, then something has gone wrong.

Conclusion

The same problem was encountered on Ubuntu 10.04 and the fix introduced above corrected the problem. I suspect that all intervening versions of Ubuntu between 10.04 and 12.04 suffer the same problem and that the same fix applies.

2012
08.11

Fix speakers and headphones playing simultaneously after upgrading to Ubuntu 12.04

Author: jpfiset / Category: Precise (12.04) / Tags: no tag / Add Comment

After upgrading to Ubuntu 12.04 (Precise Pangolin) on a Dell Inspiron 1720, the speakers continued playing even after plugging in a set of headphones. This problem has been reported and fixed in multiple forums. However, the fix requires a model number, which can not be easily guessed. Therefore, this post is meant to help those who have a machine similar to the Dell Inspiron 1720.

References:

This note applies to:

Ubuntu 12.04
Dell Inspiron 1720

The fix is applied by using the following steps:

Edit /etc/modprobe.d/alsa-base.conf and modify the appropriate line
Reboot computer

Edit alsa-base.conf

sudo gedit /etc/modprobe.d/alsa-base.conf

1	sudo gedit /etc/modprobe.d/alsa-base.conf

Initially, the file contained the following line:

options snd-intel8x0m index=-2

1	options snd-intel8x0m index=-2

This line must be commented out (in case you want it back) and replaced as follows:

# options snd-intel8x0m index=-2
options snd-intel8x0m index=-2 ac97_quirk=1 buggy_irq=1 enable=1

1 2	# options snd-intel8x0m index=-2 options snd-intel8x0m index=-2 ac97_quirk=1 buggy_irq=1 enable=1

After saving the file, rebooting the computer is all that is required.

2012
06.25

DD-WRT Router with Multiple Public IP Addresses

Author: jpfiset / Category: General / Tags: no tag / 2 comments

This note explains how to add new public IP addresses, in excess of the first static IP address, to the WAN interface of a DD-WRT router. All public addresses are assigned to computers that reside within the LAN network served by the router. Therefore, network address translation (NAT) is performed between the public addresses and the addresses assigned internally. This notes is written after it was successfully performed on:

ASUS RT-N16 Wireless Router
DD-WRT v24-sp2 (08/07/10) mega (SVN revision 14896)
ISP: TekSavvy

References:

When enquiring to receive a new static IP address from my ISP, I found out that a subnet could be leased for a monthly fee. I selected a subnet containing two IP addresses which was assigned to my internet service. The new addresses were communicated using a slash notation: XXX.XXX.XXX.XXX/30.

Although a /30 subnet might suggest that four distinct addresses are available, there are only two. In fact, each subnet contains two addresses that have special meaning: the first, which is the subnet identifier; and, the last, which is the subnet broadcast address. Therefore, the first address available for assignment in a subnet is the one after the subnet identifier. For example, if the assigned subnet was 1.2.3.4/30, then the subnet identifier would be 1.2.3.4, the broadcast address would be 1.2.3.7 and the available addresses would be 1.2.3.5 and 1.2.3.6.

For simplicity in the following examples, we will assume that the assigned subnet is 1.2.3.4/30. Also, it will be assumed that the public address 1.2.3.5 is assigned to a computer that is manually set with the LAN address 192.168.1.40.

Solution

The solution is two-fold. First, assign one of the new public IP addresses to the router’s WAN interface. Then, use firewall rules to route packets to and from the desired computer within the LAN.

Although the solution calls for entering commands through the router’s web interface, I suggest you test those commands by entering them at the command line using a telnet or SSH session to your router. Once this works well, transcribing the commands to the web interface is a good way to save those changes in case the router is rebooted.

Assign Public Address

Using a web browser, open the web interface to your router. This is usually done by directing your browser to an address similar to: 192.168.1.1.

Direct your browser by selecting the “Administration” tab, followed by the “Commands” sub-tab.

In the text box titled “Commands” under “Command Shell”, enter the commands to assign the public address to the WAN interface. Use the example below as a template and substitute the addresses according to your situation:

WANIF=`/sbin/get_wanface`
/sbin/ifconfig $WANIF:1 1.2.3.5 netmask 255.255.255.252 broadcast 1.2.3.7

1 2	WANIF=`/sbin/get_wanface` /sbin/ifconfig $WANIF:1 1.2.3.5 netmask 255.255.255.252 broadcast 1.2.3.7

Once this is entered in the text box, save the changes by pressing the button titled “Save Startup”.

Firewall Rules

To assign the firewall rules, the text box mentioned in the previous step is used. However, when saving the content of the firewall rules, the button titled “Save Firewall” is used instead.

In the firewall rules, one command is used to map the public address to the internal address; one command is used to map the internal address to the public address, and; one command is used to accept each port that should be forwarded.

Use the following template and substitute the appropriate addresses and ports:

/usr/sbin/iptables -t nat -I PREROUTING -d 1.2.3.5 -j DNAT --to 192.168.1.40
/usr/sbin/iptables -t nat -I POSTROUTING -s 192.168.1.40 -j SNAT --to 1.2.3.5
/usr/sbin/iptables -I FORWARD -d 192.168.1.40 -p tcp --dport 80 -j ACCEPT
/usr/sbin/iptables -I FORWARD -d 192.168.1.40 -p tcp --dport 22 -j ACCEPT

/usr/sbin/iptables -t nat -I PREROUTING -d 1.2.3.5 -j DNAT --to 192.168.1.40

/usr/sbin/iptables -t nat -I POSTROUTING -s 192.168.1.40 -j SNAT --to 1.2.3.5

/usr/sbin/iptables -I FORWARD -d 192.168.1.40 -p tcp --dport 80 -j ACCEPT

/usr/sbin/iptables -I FORWARD -d 192.168.1.40 -p tcp --dport 22 -j ACCEPT

The above example forwards HTTP (port 80) and SSH (port 22) requests to the internal computer.

Reboot Reouter

For the changes to take effect, the router must be rebooted. Using the router’s web interface, navigate to “Administration” tab and the “Management” sub-tab. Finally, press the button titled “Reboot Router” at the bottom of the page.

2012
03.24

Tethering iPhone 5.1 on Ubuntu 11.10

Author: jpfiset / Category: Oneiric (11.10) / Tags: no tag / Add Comment

This blog site already features an note on tethering the iPhone to Ubuntu (http://www.bitsbythepound.com/tethering-iphone-on-ubuntu-11-04-397.html). However, since upgrading to iOS 5.1, when the iPhone is connected to the Ubuntu platform, an error is reported stating thatÂ â€œUnhandled Error Lockdownâ€.

This note applies to:

Ubuntu 11.10 (Oneiric)
iPhone 5.1

References:

The solution offered by this note is to:

Install the package repository offered by Paul McEnery
Adjust the package repository to be picked up in oneiric
Install the necessary packages from the repository
Configure

Install Package Repository from Paul McEnery

sudo apt-get install python-software-properties
sudo add-apt-repository ppa:pmcenery/ppa

1 2	sudo apt-get install python-software-properties sudo add-apt-repository ppa:pmcenery/ppa

Adjust Package Repository for use in Oneiric

I applaud the work done by Paul McEnery in providing us the tools to use the iPhone. Unfortunately, the package repository is not available for Ubuntu 11.10. On the other hand, the package repository for Natty (11.04) seems to work just fine for Oneiric. In this step, the package list is modified to point to the Natty version.

sudo gedit /etc/apt/sources.list.d/pmcenery-ppa-oneiric.list

1	sudo gedit /etc/apt/sources.list.d/pmcenery-ppa-oneiric.list

While editing the file, replace “oneiric” to “natty” and save again. The resulting file should look something like:

deb http://ppa.launchpad.net/pmcenery/ppa/ubuntu natty main
deb-src http://ppa.launchpad.net/pmcenery/ppa/ubuntu natty main

1 2	deb http://ppa.launchpad.net/pmcenery/ppa/ubuntu natty main deb-src http://ppa.launchpad.net/pmcenery/ppa/ubuntu natty main

Install Necessary Packages

sudo apt-get update
sudo apt-get install  ifuse libimobiledevice2 libimobiledevice-utils

1 2	sudo apt-get update sudo apt-get install ifuse libimobiledevice2 libimobiledevice-utils

Configure

The first step of configuration is to tether the iPhone to the platform using the USB connector. Then, run the following command:

idevicepair unpair && idevicepair pair

1	idevicepair unpair && idevicepair pair

Finally, unplug and re-connect the iPhone. The error should not be reported. Instead, all services from the iPhone should be available.

2012
03.24

Fix jumpy mouse with PlayOnLinux (wine) in Ubuntu

Author: jpfiset / Category: Oneiric (11.10) / Tags: no tag / Add Comment

Since upgrading to Ubuntu 11.10, some games that used to run perfectly using PlayOnLinux started to display unwanted behaviour. In particular, the mouse jumps from the expected position in Starcraft: Broodwar. This behaviour prevents efficient playing. Researching the Internet shows that many other games are plagued by the same problem.

This note applies to:

Ubuntu 11.10
PlayOnLinux 4.0.16
Wine 1.3.18

References:

Many solutions are offered on the Internet which did not work on my system. However, the problem appears fixed in a newer version of Wine. The approach offered in this note is to install Wine 1.4. The latest version of Wine is not yet available via the packages offered by Ubuntu. However, the latest version (beta) is available via the WineHQ’s PPA. The following steps adds a new package repository and updates Wine to the latest version available from this repository. As an interesting note, Wine 1.4 is available via the package named wine-1.3.

sudo apt-get install python-software-properties
sudo add-apt-repository ppa:ubuntu-wine/ppa
sudo apt-get update
sudo apt-get dist-upgrade

sudo apt-get install python-software-properties

sudo add-apt-repository ppa:ubuntu-wine/ppa

sudo apt-get update

sudo apt-get dist-upgrade

After those changes, you can verify the version of the currently installed version of Wine with the following command.

wine --version

1	wine --version

Conclusion

Wine and PlayOnLinux are great tools. The complexity of the task performed by those tools is such that one must expected some unstable versions. This note demonstrated how a user can jump into experimental versions of Wine to access solutions earlier than pushed by the standard packages.

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