Update README.md

Author: farhanhvf

README.md

@@ -1,2 +1,102 @@
 # Android-RFID-NFC-Card-Reader-Integration
 This article will guide you how to integrate RFID NFC Card Reader in your android application
+
+## Getting Started
+RFID is the process by which items are uniquely identified using radio waves, and NFC is a specialized subset within the family of RFID technology. Specifically, NFC is a branch of High-Frequency (HF) RFID, and both operate at the 13.56 MHz frequency. NFC is designed to be a secure form of data exchange, and an NFC device is capable of being both an NFC reader and an NFC tag. This unique feature allows NFC devices to communicate peer-to-peer.
+
+### Prerequisites
+Before starting the integration you need to ready these three things:
+
+1. Android Basics
+2. NFC Enabled Device
+3. NFC Tag
+
+To enable NFC on your android device, go to Settings -> More -> and enable it
+
+### Integration
+You need to implement changes in the following parts of your Android app for basic integration of RFID Card Reader
+
+1. Manifest 
+2. Resource folder
+3. Main Activity class
+
+#### 1. Manifest
+Add these lines in manifest:
+
+-	NFC Permission
+  ```
+  <uses-permission android:name="android.permission.NFC" />
+  ```
+-	NFC Feature
+  ```
+  <uses-feature android:name="android.hardware.nfc" android:required="true" />
+  ```
+-	Intent Filter to catch action NDEF_DISCOVERED
+  ```
+  <intent-filter>
+   <action android:name="android.nfc.action.NDEF_DISCOVERED" />
+   <category android:name="android.intent.category.DEFAULT" />
+   <data android:mimeType="text/plain" />
+  </intent-filter>
+
+  ```
+-	Meta Data
+  ```
+  <meta-data
+   android:name="android.nfc.action.TECH_DISCOVERED"
+   android:resource="@xml/nfc_tech_filter" />
+
+  ```
+
+#### 2. Resource folder
+Create file named **nfc_tech_filter.xml** in *-XML*- folder with the following contents:
+
+```
+<?xml version="1.0" encoding="utf-8"?>
+<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
+    <tech-list>
+        <tech>android.nfc.tech.Ndef</tech>
+        <!-- class name -->
+    </tech-list>
+   </resources>
+
+```
+#### 3. Main Activity class
+Add these two changes & Enjoy running code with RFID NFC Card Reader Integrated
+-	In OnCreate() method
+  ```
+  nfcAdapter = NfcAdapter.getDefaultAdapter(this);
+  if (nfcAdapter == null) {
+    // Stop here, we definitely need NFC
+    Toast.makeText(this, "This device doesn't support NFC.", Toast.LENGTH_LONG).show();
+    finish();
+  }
+  readFromIntent(getIntent());
+
+  pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
+  IntentFilter tagDetected = new IntentFilter(NfcAdapter.ACTION_TAG_DISCOVERED);
+  tagDetected.addCategory(Intent.CATEGORY_DEFAULT);
+
+  ```
+-	readFromIntent() method to Read from NFC Tag
+
+  ```
+  private void readFromIntent(Intent intent) {
+    String action = intent.getAction();
+    if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action)
+            || NfcAdapter.ACTION_TECH_DISCOVERED.equals(action)
+            || NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {
+        Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
+        NdefMessage[] msgs = null;
+        if (rawMsgs != null) {
+            msgs = new NdefMessage[rawMsgs.length];
+            for (int i = 0; i < rawMsgs.length; i++) {
+                msgs[i] = (NdefMessage) rawMsgs[i];
+            }
+        }
+        buildTagViews(msgs);
+     }
+ }
+
+ ```
+