Update README.md

README.md

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 This is an Android library project that simplifies the usage of ZBar Android SDK (http://sourceforge.net/projects/zbar/files/AndroidSDK/) for scanning bar codes from within your Android application.
 
+### How to use?
+
+1. Download this project and add it as a library project to your existing Android app.
+2. Open the AndroidManifest.xml file in your project and add these lines under the manifest element:
+
+<pre>
+&lt;uses-permission android:name="android.permission.CAMERA"/&gt;
+&lt;uses-feature android:name="android.hardware.camera" /&gt;
+</pre>
+
+3. Within the application element, add the activity declartion:
+
+<pre>
+&lt;activity android:name="com.dm.zbar.android.scanner.ZBarScannerActivity"`
+            android:screenOrientation="landscape"
+            android:label="@string/app_name" /&gt;
+</pre>
+
+3. Now from inside your Android application, you can launch the ZBarScanner from any activity using this intent:
+```java
+Intent intent = new Intent(this, ZBarScannerActivity.class);
+startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
+```
+
+4. To receive the results of the SCAN, add this method to your activity:
+```java
+@Override
+protected void onActivityResult(int requestCode, int resultCode, Intent data)
+{    
+    if (resultCode == RESULT_OK) 
+    {
+        // Scan result is available by making a call to data.getStringExtra(ZBarConstants.SCAN_RESULT)
+        // Type of the scan result is available by making a call to data.getStringExtra(ZBarConstants.SCAN_RESULT_TYPE)
+        Toast.makeText(this, "Scan Result = " + data.getStringExtra(ZBarConstants.SCAN_RESULT), Toast.LENGTH_SHORT).show();
+        Toast.makeText(this, "Scan Result Type = " + data.getStringExtra(ZBarConstants.SCAN_RESULT_TYPE), Toast.LENGTH_SHORT).show();
+        // The value of type indicates one of the symbols listed in Advanced Options below.
+    }  
+}
+```  
+
+### Advanced Options
+If you are interested in scanning only QR codes, you can specify the SCAN mode in the intent as shown below:
+```java
+Intent intent = new Intent(this, ZBarScannerActivity.class);
+intent.putExtra(ZBarConstants.SCAN_MODES, new int[]{Symbol.QRCODE});
+startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
+```
+
+You can pass an array or integers for SCAN_MODES. The exact values are specified in net.sourceforge.zbar.Symbol class:
+```java
+public static final int NONE = 0;
+public static final int PARTIAL = 1;
+public static final int EAN8 = 8;
+public static final int UPCE = 9;
+public static final int ISBN10 = 10;
+public static final int UPCA = 12;
+public static final int EAN13 = 13;
+public static final int ISBN13 = 14;
+public static final int I25 = 25;
+public static final int DATABAR = 34;
+public static final int DATABAR_EXP = 35;
+public static final int CODABAR = 38;
+public static final int CODE39 = 39;
+public static final int PDF417 = 57;
+public static final int QRCODE = 64;
+public static final int CODE93 = 93;
+public static final int CODE128 = 128;
+```
+
+If you do not specify scan_modes, the scanner processes all the above listed types.
+
+But if you are interested in QRCodes and ISBN, you would setup the intent as follows:
+```java
+Intent intent = new Intent(this, ZBarScannerActivity.class);
+intent.putExtra(ZBarConstants.SCAN_MODES, new int[]{Symbol.QRCODE, Symbol.ISBN10, Symbol.ISBN13});
+startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
+```
+
+### Example app
+There is a ZBarScannerDemo app in the examples folder which demonstrates the use of this library.
+
+### Tests
+I have tested the scanner functionality on these devices without any issues so far:
+* Motorola Droid running Android 2.2.3
+* HTC Thunderbolt running Android 2.3.4
+* Samsung Galaxy Nexus running Android 4.0.4
+
+###Credits
+Almost all of the code for this library project has been taken from these two places:
+1. CameraPreview stuff from Android SDK APIDemos 
+2. The ZBar Android SDK: http://sourceforge.net/projects/zbar/files/AndroidSDK/
+
+###License
+MIT
+
+
+
+