adb not detecting your Android Device ?

To debug your mobile application on an actual device, Android requires you to connect your device to your computer and test if it is detectable by Android.

To achieve that , you need to go to -

<android-install-location>/sdk/platform-tools 

and give the command

adb devices

You might not have platform-tools  installed by default.

So install it through the SDK Manager before you read further.

Ideally the output of  the command should be the serial number of your device.

But many times if the device is not read by Android you end up seeing blank.

To troubleshoot , make sure that -

1.  USB debugging is enabled on your Android phone
2.  Ensure that you have successfully downloaded and installed Google USB Driver Package
3.  In case of Samsung devices,install Samsung Kies as it installs device drivers.
4. Goto Control Panel->System ->Device Manager and make sure that none of the drivers show any error.

For Samsung devices Samsung Kies software installs device drivers.

There are different Kies versions for different Samsung devices so make sure you have installed the right Kies

Eg:  Kies 2 supports Samsung Note 2 but Kies 3 doesnt.
If you try to connect a Samsung Note 2 with Kies 3 installed,you will observe device driver errors.
You will then have to install Kies 2

Adding extra packages to Android SDK

Recently I wanted to download some additional packages to my existing Android SDK.

The simplest way to go about anything is seemingly the UI way.

So I went ahead and launched my Android SDK from the Start Menu.,and as expected it displayed the sdk contents.But to my absolute amazement ,even thought the updates options was checked the Packages View would not show me any updates to the folders.
All it would show me was that updates were available for "Android SDK Tools" and "Android SDK Platform-tools".

Since I had no use for an update I happily ignored those two and focussed on the Extras folder which is where the said packages were supposed to reside.
No matter how many restarts I made to the SDK Manager (including launching it from eclipse,starting it from Start menu with administrator permissions)

Finally I decided to do the minimal and updated the suggested updates to  "Android SDK Tools" and "Android SDK Platform-tools" and restarted the SDK  Manager

And to my utter surprise .....

The Packages View goes ahead and shows all that is available for download in all the expected folders: Tools,Various Android Versions and the Extras.
now it was easy to download whatever I required .

Moral of the Story : Need an extra package? update exisiting packages and restart SDK Manager (run as administrator)