Suramya's Blog : Welcome to my crazy life…

April 16, 2013

Adafruit launches educational show aimed at kids

Filed under: Computer Hardware,My Thoughts,Tech Related — Suramya @ 4:11 PM

If you are like me you love tinkering with technology and honestly speaking there is no age too early to start teaching kids about electronics and how they work. Adafruit has launched an educational show aimed at kids which is going to be a episode based series and their first episode is titled “A is for Ampere” and teaches the basic theory behind electrical current.

If you have young kids in the family, you should definitely check it out. I am going to try get Vir hooked on to it once he reaches the age where he doesn’t try to eat everything that is given to him. Don’t think Surabhi and Vinit will be happy with me if he manages to swallow a diode or a capacitor. 🙂

Source: Adafruit Launches educational show for Kids

– Suramya

March 30, 2013

Will you get fired over your Twitter history?

Filed under: Interesting Sites,My Thoughts,Tech Related — Suramya @ 6:00 PM

Ideally you should know if you have posted something online that will get you fired, but as we all know there are people in the world who are a bit slow and need extra help in figuring out stuff. So for these people there is a new web service called “FireMe! Who wants to get fired?” that goes over your tweets and uses an algorithm to figure out the chances of you getting fired if you boss reads your Twitter history.

Personally I think that if you need help figuring out whether you said something online that will get you fired then there is a high chance that you actually did post something which will get you fired. 🙂

According to the site, they are doing this to raise awareness about the dangers of public online data. Plenty of folks have been fired for things they posted online. Don’t become another statistic, post responsibly.

Thanks to PopSci for the initial Link,

– Suramya

March 28, 2013

A Wedding ring that reminds you of the Day of your anniversary by burning your finger.

Filed under: Humor,My Thoughts,Tech Related — Suramya @ 1:05 AM

Found this while surfing the web. This is not an actual product yet but once it’s available I think people who don’t know how to setup a reminder on their phone or online (I use google Calendar), are really forgetful and like pain might want to invest in this. As per the site once the ring is on sale you can buy it for a measly price of $760 only.

From the product description:

If you’re prone to memory lapses — or simply have too many secret second families on the side — then you may want to consider the Remember Ring. Here’s how it works: A full 24 hours before your special day begins, a “hot spot” on the ring’s interior will begin to warm up to 120º F for approximately 10 seconds. And in case that doesn’t do the trick, the ring will continue to warm up every hour, on the hour, all day long!

120 Deg F (~49 Deg C)! Ouch… I think I will stick to my SMS alerts and reminders. 🙂

Thanks to Gadget Lab for the link.

– Suramya

March 24, 2013

“Cloud haters: You too will be assimilated” – Yeah Right…

Filed under: My Thoughts,Tech Related — Suramya @ 10:39 PM

Cloud Computing is the supposedly ultimate in computing experience where all data is stored on online central servers and all you need is a computer with internet connection to access the applications/data. People keep talking about this as if this is something new but it’s not. If you remember the era of computing before personal computers became popular that is exactly what they used (albeit on a much smaller scale and with lesser speed). So its not something new, and it’s not something that will fit all use cases. Today I read an article on ZDNet where the author (Jason Perlow) talks about Cloud Computing and basically tells us that we should stop whining and embrace this new and great technology because we don’t have a choice. My response: *yeah right*.

Don’t take me wrong, Cloud computing has its advantages, but it has it’s disadvantages as well. Telling folks who point out the disadvantages that their complaints don’t matter and that they have to come on to the bandwagon no matter what is irresponsible and potentially dangerous. You should go read the article and see what Jason has to say about this. I am not going to nitpick on his article as he is entitled to have an opinion. 🙂

Here are some reasons that I think you need to be careful about Cloud computing:

Data Access Control/Security: When I have a document on my local computer, I control who can see it. If someone who I don’t want to see the document wants to view it, they will have to break into my computer, steal it, put a court order or something similar. The same is not the case with data stored in the Cloud. In that case the company you are using to store the data controls who can be granted access and for what reason. A government can send a legal request to your provider or a bored employee can decide to check out what you have stored in the account. The company hosting the data will react based on what is best for them and not what is best for you. If you got a court order to share your data then you have to option of contesting it but if your provider gets the same order they will comply with it because it’s easier for them.

Secondly, people target the cloud servers because it’s a bigger target and the payoff is much larger if they manage to break in. They don’t care about your ‘secret recipe’ or your financial documents so they won’t target your computer specifically, but if they break into the Cloud server they get all that and a whole lot more so plenty of folks will be trying to break in.

One of the common responses that some people give when we talk about people breaking into cloud servers is that these companies hire some of the smartest people in the industry so your data is safe. However that is not true as it only takes one vulnerability and since no system is perfect sooner or later someone will get access. The more the no of people trying to break in the higher the chances are that someone will succeed.

System/Service Availability: You spend a couple of days uploading your data to a cloud based service, what guaranty do you have that the company won’t decide that it’s not worth it and shut it down? It’s happened too many times in the past for anyone to claim that this is not a possibility. What if you have a critical presentation and Google Docs has an outage, or your ISP (Internet Service Provider) has an outage? It has happened multiple times this year (e.g. Google Drive , Microsoft Cloud Storage.

Personally I don’t like access to my data dependent on others. I have been burnt multiple times by that in the past so I prefer running my own services whenever I can and keep multiple backup copies of stuff I have put up online.

Any new technology has it’s downsides and we should be aware of the risks before we start putting all our eggs in the same basket.

Well this is all for now. Will post more later.

Original source: Cloud haters: You too will be assimilated | ZDNet.

– Suramya

March 12, 2013

Does your Handwriting suck? Now you can have a machine write for you.

Filed under: My Thoughts,Tech Related — Suramya @ 1:20 AM

This is something I really need. 🙂 Those of you who know me, know that my writing is horrible and most of the time only I can read it. Here’s an invention by students from Olin College that solves this problem. Meet Herald, a machine that can produce beautiful calligraphy.

The machine uses a gantry to move the writing tip along the X and Y axes. The flexible-nib calligraphy pen is mounted on a sprocket which rotates the tip onto the writing surface, taking care of the third axis. The rig was beautifully rendered from their CAD drawings, then tweaked to ensure the smoothest motion possible before the quintet of Sophomores began the physical build.

Check it out in action at Herald Calligraphy. Now if only someone makes a portable version of this, I will be all set 🙂

Thanks to Hackaday.com for the initial scoop.

– Suramya

March 8, 2013

Citrix on Raspberry Pi: Updated instructions and working download image

Filed under: Knowledgebase,Linux/Unix Related,Tech Related,Tutorials — Suramya @ 2:36 PM

A couple of folks have reached out to me via email/messages to tell me that the instructions I posted at the Raspberry Pi forums don’t work with the latest version of Rhaspbian. Basically the problem is that the latest version of the Citrix client is not compiled for the armhf architecture (Which is what the latest version of Rhaspbian OS is compiled for), so you need to download and install the armel version of the OS (‘Soft-float Debian “wheezy”’) from http://www.raspberrypi.org/downloads.

To make life simpler for people I have created a snapshot of my Pi install with Citrix installed and configured. You can download it from here. The image is 4GB so you will need to use a card of atleast that size when using this image. Follow these steps to install the image to an SD card in Linux:

  • Download the image file from the mirror (Approx 1GB compressed)
  • Unzip the file using the command
  • unzip Raspberry_Citrix.img.zip
  • Find out what the partition the SD card you are using has been assigned running the following command as root
  • fdisk -l

    Once you run the command, you will get an output that will show you all the disks attached to your system, look for the entry that corresponds to your card. In my case it looked like this:

     Disk /dev/sde: 3965 MB, 3965190144 bytes
    122 heads, 62 sectors/track, 1023 cylinders, total 7744512 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x00016187
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/sde1            8192      122879       57344    c  W95 FAT32 (LBA)
    /dev/sde2          122880     7744511     3810816   83  Linux
    
  • So now we know that the card is at /dev/sde. All we have to do is write the image to the card and that is done using the following command. Make sure you replace the /dev/sde with the correct path otherwise you will end up destroying all data on the wrong drive.
  • dd if=Raspberry_Citrix.img of=/dev/sde bs=4096

    You will not see any output on the screen so don’t worry about it, just let it run and wait for the process to complete as it will take some time because of the amount of data being written. Once the process completes you can eject the card and if all went well you should be able to boot the Raspberry Pi from the card.

The login password for this image is root/password, please do change the password if you use the image. Let me know if you have any questions or have an issue using this image.

Update (3/28/2013): Adding instructions on how to write the image when using windows. (Please note that I haven’t tested the windows instructions as I don’t have a windows machine. Use at your own risk)

Once you download the zip file from the mirror, right-click on it and select extract (I think that’s what it says, but I don’t have a windows machine so can’t confirm). After the image is extracted you will have a file called Raspberry_citrix.img on your computer. Now follow these steps to write the image to an SD card (Instructions taken from eLinux)

  • Insert the SD card into your SD card reader and check what drive letter it was assigned. You can easily see the drive letter (for example G:) by looking in the left column of Windows Explorer. If the card is not new, you should format it and make sure there is only one partition (FAT32 is a good choice); otherwise Win32DiskImager can make corrupt your SD card!
  • Download the Win32DiskImager utility. The download links are on the right hand side of the page, you want the binary zip.
  • Extract the executable from the zip file and run the Win32DiskImager utility. You should run the utility as Administrator!
  • Select the Raspberry_citrix.img image file you extracted earlier
  • Select the drive letter of the SD card in the device box. Be careful to select the correct drive; if you get the wrong one you can destroy your data on the computer’s hard disk!
  • Click Write and wait for the write to complete.
  • Exit the imager and eject the SD card.

You should also go through the Basic setup guide for Raspberry Pi. Hope this helps.

– Suramya

August 4, 2012

Reinstalled system after accidental removal of KDE. Pleasantly surprised by ease of configuration

Filed under: Computer Tips,Knowledgebase,Linux/Unix Related,Tech Related — Suramya @ 11:19 PM

Last night I was trying out stuff on my computer and decided to install virtual box on the system to allow me to install Windows in a virtual environment. I ran the command to install virtual box and then said ok without paying too much attention to what it was doing. As a punishment for that, the apt-get program proceeded to uninstall most of the KDE environment on the system leaving me with Gnome as my primary desktop (and there is no way I am using Gnome as my primary desktop). I could have fixed it by reinstalling KDE but since I had been thinking about removing the 32 bit Debian and installing the 64 bit version I decided to use this opportunity to do so and downloaded the 64 bit version from the Debian site, put it on a USB drive and proceeded with the install which took about an hour to complete.

After the install completed, I upgraded the system to the latest ‘Unstable’ build (Debian Unstable has the latest software packages so I prefer using it as opposed to Stable which is rock solid but has fairly dated software versions.) which took most of the night thanks to the no of packages to download and install. Once everything was upgraded I started customizing my setup and initially was dreading the amount of time it would take to get both my monitors working (based on previous experience) but surprisingly this time I didn’t have to do a lot to get both the monitor’s working.

If you remember, the last time I tried enabling the second monitor I hit a lot of hurdles mostly thanks to the mess I had made with my previous meddling and experimentation but this time it was fairly simple. I thought that I would follow the same steps I had the last time I installed the monitor so I started by installing the fglrx driver but the latest version of the driver no longer supports my chipset (ATI RS880 [Radeon HD 4250]) and the installer told me to install the free Radeon driver in the package xserver-xorg-video-radeon instead. So I did that after purging the fglrx driver (See here for instructions). I also had to install the Firmware for the Radeon card which I did by issuing the following command:

apt-get install firmware-linux-nonfree

After the driver was installed I rebooted (to make sure all systems started up clean) and setup my dual monitors by following these steps:

  • Click on Start -> System Settings
  • Click on ‘Display and Monitor’ under Hardware.
  • Under ‘Size & Orientation’ change the ‘Position’ dropdown to ‘Left Of’ the first (If your second monitor is to the left of the first one)
  • Set the Primary output to the monitor where you want the Task bar etc to show up. If you don’t know which monitor is which, click on the identify Outputs button.
  • Once you are done, Click on ‘Apply’ and if all looks good you can set it as default by clicking on the ‘Save as Default button’.

If you are ok with the resolutions available to you in the dropdowns above then you are done and you can skip the steps below.

Unfortunately for me I wanted a resolution of 1440×900 as the default instead of 1600×900 which was too small & the fonts looked pretty bad at that resolution and the 1280×1024 which was the next available size looked worse because my of my monitor shape (16:9 resolution as opposed to 4:3). So I had to do a bit more work to fix the problem.

First I tried manually setting the mode to 1440×900 using xrandr but I got an error message that “xrandr ‘cannot find mode'”. So I did a little Google search and found a forum post where another person was having the same issue. That link told me how to add a custom mode to my system which I did using the following steps:

First we need to figure out if our configuration will support the mode we are trying to use and if so get the modeline we need for the new config, so we run this command:

cvt 1440 900

If the system can support the resolution specified (1440×900 in the above example) it will return a line that looks something like:

# 1440x900 59.89 Hz (CVT 1.30MA) hsync: 55.93 kHz; pclk: 106.50 MHz
Modeline "1440x900_60.00"  106.50  1440 1528 1672 1904  900 903 909 934 -hsync +vsync

Luckily for us my system can support the resolution so we then need to tell xrandr about the new mode using the following command:

xrandr --newmode "1440x900"  106.50  1440 1528 1672 1904  900 903 909 934 -hsync +vsync 

Where the first paramter (“1440×900” in this case) is an identifier and the rest is the information returned by cvt. (If successful the command will return no output.)

Then we need to tell the system that both the displays (called DVI-0 and VGA-0 on my system) should use the new mode which is accomplished using the following commands:

xrandr --addmode VGA-0  "1440x900"
xrandr --output VGA-0 --mode 1440x900
xrandr --addmode DVI-0  "1440x900"
xrandr --output DVI-0 --mode 1440x900

If the commands were successful then your screen should resize and start using the new resolution. Now that this is done we want this to happen everytime we log in without having to run the commands manually.

When you click on the ‘Save as Default’ button in the ‘Size & Orientation’ dialog box, KDE saves your settings in a file at the following location: ~/.kde/share/config/krandrrc that is executed everytime you log in to KDE. So to make the changes permanent we have to modify the file with the new settings.

The file contains the following lines right at the top:

[Display]
ApplyOnStartup=true
StartupCommands= 

We need to modify the StartupCommands= line to use our new settings. Basically it should contain all the commands we used above in a single line delimited by \n. On my system the file looks like the following after I updated it:

[Display]
ApplyOnStartup=true
StartupCommands=xrandr --newmode "1440x900"  106.50  1440 1528 1672 1904  900 903 909 934 -hsync +vsync\nxrandr --addmode DVI-0  "1440x900"\nxrandr --addmode VGA-0
  "1440x900"\nxrandr --output VGA-0 --pos 1450x0 --mode 1440x900 --refresh 59.9782\nxrandr --output DVI-0 --pos 0x0 --mode 1440x900 --refresh 59.9782\nxrandr 
--output DVI-0 --primary

Once you make the change, save the file and log out. After loging out I usually restart X to make sure everything came up cleanly and then if all went well then the changes should take effect after you log in.

Hope others find this useful when configuring their systems.

– Suramya

PS: The best part is that after re-formating and using the Opensource version of the display driver instead of the proprietary one, my average memory usage went down from about 3GB about 1GB with all the same programs running in the background. 🙂

July 19, 2012

Sensordrone brings us one step closer to having a real life StarTrek Tricorder

Filed under: Interesting Sites,My Thoughts,Tech Related — Suramya @ 10:56 PM

Anyone who has watched Star Trek would love to get their hands on a Tricorder, but till recently Tricorders have been the stuff of Science Fiction. However slowly but steadily the technology to build them is getting there. We have the Tricorder Project which gave us the blue prints to create a basic version of the tricorder. It was cool and let you watch Magnetic field fluctuations etc (among other things) but still required you to build the thing yourself. Now comes Sensordrone, a project that pairs a sensor-heavy dongle with your smartphone and then opens them up for use using different apps. Me Want! 🙂

Its basically a sensor package that you pair with your phone and then run apps to visualize the various data, with no need to build the hardware yourself (I am more of the software building person.) Sensordrone is a Kickstarter project so its not really a real product yet but since people have pledged $153,655 for the project already (target was $25,000), it does seem like this is going to be an actual release pretty soon. They are aiming for an Oct 2012 release and it would cost about $200 or so. When it comes out I think I probably will end up buying it… Does that make me a Geek? Hell yeah… 🙂

Excerpt from their website:

If you have a Sensordrone, you can run apps on your tablet or smartphone to monitor carbon monoxide and air quality, find gas leaks, measure your child’s temperature, log the weather, and much more.

For example, apps using the capacitance sensor can work as a stud finder, a proximity monitor, or a liquid level monitor. Apps using the pressure sensor can work as a barometer, an altimeter, calculate elevation differences so you can measure the height of a building, be hooked up to a pressure cuff to work as a blood pressure monitor, and more. Humidity sensing is not just for weather, it determines comfort level for infants, finds the optimum conditions for storing foods, and could even help prevent mold from growing in your home

Sensordrone makes any sensor application as easy as running an app!

Thanks to Engadget: Sensordrone lets your smartphone monitor temperature, air quality, inebriation for the heads up.

– Suramya

July 15, 2012

Got the Jelly Bean Update on my Nexus

Filed under: My Thoughts,Tech Related — Suramya @ 10:21 PM

After waiting for a day for the update to show up on my Nexus, I forced the update to download on my Nexus. It was a fairly simple process which I had used before to get the 4.0.4 update as well. The steps are as following

  • Go to Settings -> Apps -> All
  • Click on Google Services Framework
  • Click on Clear Data
  • Click on ‘Force Stop

Once you do this you need to:

  • Goto Settings -> About Phone
  • Click on ‘Check for updates’

You might have to do this a couple of times (I had to do it 3 times) before the update shows up and downloads. The overall process took about 1/2 hour including the time required for the update to download.

Have been using it for about 2+ days so far and wanted to document my reactions/findings:

* System is now extremely fast, the screen switching is about 3-4 times faster and smoother.
* The Google bar on the top is a bit distracting. It had a black background previously, now its grey so is noticeable.
* Love the voice recognition. The system can do voice recognition without being connected to the web (tested in Airplane mode) and is about 90% accurate. Seems like its a bit more accurate when connected to the web, but don’t have any hard data for that.
* Battery life is a lot improved, my phone went about 2 days with regular usage. (I was getting about 1 day+ earlier)
* Camera gives a visual feedback when a photo is taken so people don’t take a million photos thinking it wasn’t taking photos.

Some downsides/issues etc:

* I think my Wireless connects gets disabled a min or so after the screen switches off. Haven’t verified it yet but if that is the case then it will be a major issue.
* The soft buttons feel a bit less reactive on some screens, but again its a bit subjective and haven’t verified it.

Overall I like the new update. I think Google did a good job with this update.

– Suramya

July 10, 2012

Wireless finally working on the RaspberryPi

I finally managed to get wireless working on the RaspberryPi (Go Me!). The main problem was that when I connected the USB dongle directly to the Pi it wasn’t getting enough power, then when I connected it via a powered USB hub I kept getting error messages. If you like you can read about me previous attempts to get the wireless working here and here. Since I didn’t feel like spending more time on this (and because I thought that the problem was caused because of a problem with the USB hub) I stopped fiddling with it. Then I had to switch the SD card I was using in the Pi (the old one was the card from my camera so I replaced it with another 2GB card) so I downloaded and installed Debian Wheezy on it.

Turns out that the Wheezy doesn’t have the same problems with the USB hub as Squeeze did, so all I had to do was plug in the stuff, install the firmware and I was ready to go. To configure the wireless network I installed wicd as I have found that to be the easiest way to work with wireless networks, I also installed the wicd-curses interface so that I could configure the system from the commandline. The commands I used were as follows:

apt-get install wicd wicd-curses

Then ran wicd-curses to configure the Wifi, That’s it. Now my Pi is connected to net wirelessly and I have one less cable running across my desk, which is great.

Well this is all for now. Will post more later, its time for me to hit the sack. Have an early day tomorrow.

– Suramya

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