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Showing posts from November, 2012

NTSC and PAL

The other day, I captured the composite video signal coming out from an infotainment device. The device had a setting which allows you to select encoding for the output signal. By setting the device to output a particular image on the composite video RCA connector (hence the waveform shown below are of unmodulated baseband video signals) and switching the device between NTSC and PAL, I was able to capture and analyse various aspects of the two standards.
Test Pattern  Here is the test pattern I used. I loaded the JPEG onto a USB flash drive and connected it to the infotainment device. The device was put in image playback mode and the selected file was rendered on the LCD display as well as output on the composite video out.
The image is composed of exactly 640 x 480 pixels which corresponds to an aspect ratio of 4:3.


A short table of differences between the two standards NTSCPALStands forNational Television System CommitteePhase Alternating LineMajor Contries using itNorth America, M…

blinky and printf on netduino using YAGARTO

AimTo run simple C programs on netduino using YAGARTO+Eclipse on Windows. Software Development ToolsA Windows PC with 3 free USB ports
I used Windows 7 Home Premium 64 bit SP1Eclipse IDE for Automotive Software Developers (32 bit for Windows)
download link | I used juno SR1 | This version includes CDTAtmel SAM-BA for Windows
download link | I used 2.12 (sam-ba_2.12.exe)YAGARTO GNU ARM toolchain (for Windows)
download link | I used 13.10.2012 (yagarto-bu-2.22_gcc-4.7.2-c-c++_nl-1.20.0_gdb-7.5_eabi_20121013.exe)YAGARTO Tools
download link | I used 18.10.2012 (yagarto-tools-20121018-setup.exe) Hardware One no. netduino buy link | I used the plain one (not plus or go) Two nos. FTDI Basic Breakout - 3.3V buy link Four nos. LEDs buy link | I used 3mm ones Four nos. 1Kilo-ohm resistors (current limiting for the above 4 LEDs) I used 1/4 watt through hole ones Two nos. Potentiometers buy link | I used 10 kilohom linear ones  One no. Tactile Switch buy link

Instructions
Install FT232RL Driver if you haven't alr…

Installing Arch Linux on a VitualBox VM (Spoon-fed version)

I have Windows 7 64-bit on my Laptop (it has 4GB RAM) and here is how I went about Installing Arch Linux on a virtual machine created using VirtualBox
Prepare the virtual machine:Make sure your computer has an active internet connectionDownload and install "VirtualBox for Windows hosts" from here.Download and install "VirtualBox Oracle VM VirtualBox Extension Pack". Just double click on  .vbox-extpack file to install it.Download the Arch Linux iso image file. The name of the latest image at the time of writing this was: archlinux-2012.11.01-dual.isoClick on "New" to create a new virtual machine for Arch Linux. Name it the same as the iso file (archlinux-2012.11.01-dual in my case) and the "Operating System" and "Version" types will automatically be selected. Set the RAM to 1024 MB, Hard Disk to VDI having capacity of 10GB.Before starting the virtual machine, right click on it and select settings and perform the following configuration…