3 bulbs 3 switches puzzle with LED bulbs

Here's the puzzle.

There are three light switches up in the attic of an old house. They control three light bulbs down in the basement. The problem is that you don't know which switch is connected to which bulb. You can make one trip down to the basement to figure this out. How are you going to do it?

Think and you'll easily come up with the traditional answer that's applicable to incandescent bulbs.

Don't know?

The answer that's expected is: Switch on one bulb for a long time, then switch it off, switch another on, and go to the basement immediately. The bulb shining has the second switch. And the warmer of the two unlit bulbs has the first switch.

What if the bulbs were made of LEDs?

Since the question isn't serious, I came up with two solutions of my own - which may or may not answer the question correctly. For educational purpose, they are:

1) Use an arduino to make one LED blink. Switch one on, keep one off. Go to basement and correlate the bulbs.
2) LEDs can emit light as well as detect light. So, if the bulbs are not arranged in an equilateral triangle fashion, switch one on, and measure the multimeter readings in the other two switches. Then go to the basement. The bulb closer to the shining bulb has the switch which showed the larger multimeter reading.

Flaws and other solutions are welcome.

Share text from computer PC to whatsapp via Android phone

There is no official desktop client for whatsapp. And this makes sharing text or links from computer to whatsapp contacts very tedious.

A usual way people do this is typing down the text using phone, or sending themselves an email via gmail which they copy to whatsapp.

But this free, open source app called QRtoWhatsapp, eliminates the need for all that hazzle.

Things you need

A QR code creator on your PC. Linux, Windows

QRtoWhatsapp app installed on your android phone

Zxing barcode scanner app installed on your android phone (asks to install the first time you run the QRtoWhatsapp app)

Whatsapp on your android phone.

To download QRtoWhatsapp go to the github repo here, and click on view RAW

Google Removes Free SMS Apps from Play Store

Early today Google has removed all the free sms apps from its Play Store.
These include Free SMS India, SMS Free, Free 2 sms, etc.

Free SMS India now returns an error "We no longer support this gateway" when you try to send an sms.

This is probably due to a Terms of Service violation and now you'll have to visit sites like way2sms or 160by2 directly through their website to send free SMS.

Blackberry messenger for Android, BBM, hands on review - features and bugs

The new BlackBerry messenger for Android has made a splashing start. In the first two days of using it, here are the main features as I see it. I will also compare these with whatsapp.

Authentication
Blackberry ID and pin is a must for BBM unlike whatsapp. This is a different philosophy regarding privacy and can't be compared. There is slight friction in adding new contacts. Scanning QR code didn't work with my 3 MP camera. But following www.pin.bbm.com/BBMPIN lets anyone add you directly, only that there's no easy way to add the URL prefix to your pin while sharing.

Private chat
The text boxes are too big, but the font is too small. There are about four icons next to messages to signify different status of the message.
There's ping option (like yahoo messenger's buzz) which is another way of saying hi.
There's also the ability to attach images, sound notes, etc. And a lot of emoticons to choose from.

Multi person chat
No image support here.
Easy to add people.

Groups
Group is the best thing about BBM. Groups are given separate space and is not like just another endless conversation. There can be discussions in different topics.
Pictures can be uploaded which can be commented upon
Checklists can be made and individuals assigned to different items.
Events can be added which appears chronologically.

Group members can be added by anyone. There can be multiple administrators.
And members who join after a long time will still be able to see previous messages, lists, pictures, etc (unlike multi person message)

In total whatsapp groups now appear child's play :-P

Bugs
Till now, I've found some small bugs.

The settings keep reverting to default.
The blackberry connected notification needs to be on for pin invites to work properly.

But considering that this is the first release, I'm sure BBM has a bright future!

What's new in whatsapp 2.11.109

Here's an unofficial change log of the latest whatsapp version released on Oct 22, 2013

The most striking new feature of this version of whatsapp is that the image upload and download are now better. The download button below a small thumbnail has been replaced by a huge low resolution thumbnail which when clicked leads to download of the image. Similarly when uploading image there is a similar large thumbnail.

While scrolling up and down in a conversation, the date of the conversation stays in a floating box on top

There are various other minor tweaks for voice messages, etc

Links posted are automatically getting image thumbnail like in Facebook and Google+

Root Android in Mysore

If you need help rooting your android phone in Mysore, without going to any mobile shop, contact me through my Google profile or email

File system structure layout of linux and Android explained

Android is built upon Linux. The way files and folders are organized in Linux/android is different from that in Windows. (I'd say it is better in Linux)

To begin with there is root. Represented by "/"
Root folder is the root of everything, the basic, the foundation, the sum total of all folders.
Rooted on the root folder is a tree of folders.
These are represented like "/system" or "/bin"
That means, the system folder is inside the root folder, so is the bin folder and so on.

When running Linux my home folder is in "/home/akshay"
My desktop files are in "/home/akshay/Desktop"

If I insert a pen drive, it gets "mounted" on to some "branch" of the "tree" eg: "/media/akshay/Transcend"

In android phone you don't get to insert pen drives. But you have sdcard! These can get mounted similarly to some branch. In my phone, sdcard's mounted at "/mnt/sdcard".
So, the external memory seamlessly merges with your internal memory. (Everything is in "/". But things inside "/mnt/sdcard" are actually stored in SD card. Things inside "/mnt/sd-ext" are stored in external storage...)

Thus, every folder on your device is under a single hierarchical order (unlike in windows where you have C:, D:, C:/Users/akshay, I:/lost/count)

PS: If you want to actually see the root folder, and its hierarchy, you'll need a good file manager on your phone. I recommend "ES File Explorer" for all its added functionalities.