Merge pull request #1 from GedaliaR/master

1. A method or two to read data from the Arduino. This makes debugging from the Arduino side easier.

2. A simple way to connect with paired devices. The method that establishes the connection with the Bluetooth device assumes that it is not yet paired (and if it is already paired the user would have to forget that device and re-pair with it).

ardutooth/build.gradle

@@ -1,11 +1,11 @@
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.3"
+    compileSdkVersion 29
+    buildToolsVersion '29.0.2'
     defaultConfig {
         minSdkVersion 14
-        targetSdkVersion 25
+        targetSdkVersion 29
         versionCode 2
         versionName "2.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -19,10 +19,11 @@ android {
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
+    api fileTree(dir: 'libs', include: ['*.jar'])
+    androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
-    compile 'com.android.support:appcompat-v7:25.3.1'
-    testCompile 'junit:junit:4.12'
+    //noinspection GradleCompatible
+    api 'com.android.support:appcompat-v7:25.3.1'
+    testImplementation 'junit:junit:4.13'
 }

ardutooth/src/main/java/io/github/giuseppebrb/ardutooth/Ardutooth.java

@@ -3,14 +3,19 @@
 import android.app.Activity;
 import android.bluetooth.BluetoothDevice;
 import android.bluetooth.BluetoothSocket;
+import android.os.Build;
+import android.support.annotation.RequiresApi;
 import android.util.Log;
 
+import java.io.BufferedReader;
 import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
 import java.util.UUID;
 
 /**
  * This singleton class represents the main component of the library.
- * It can be used to easily set a stable connection with an Arduino and to send data to it using the Serial Monitor.
+ * It can be used to easily set a stable connection with an Arduino and to send/receive data to/from it using the Serial Monitor.
  *
  * <p>The first thing you need is to create or get an instance of {@link Ardutooth} using something like
  * {@code Ardutooth mArdutooth = Ardutooth.getInstance(this)} where parameter represents the instance of
@@ -65,7 +70,7 @@ public boolean isConnected() {
         } catch (Exception e) {
             Log.d(Ardutooth.TAG, "An error occurred while retrieving connection", e);
         }
-        return mBtHandler.connected;
+        return BluetoothHandler.connected;
     }
 
     /**
@@ -206,4 +211,38 @@ public void sendBoolean(boolean value) {
                 e.printStackTrace();
             }
     }
+
+    /**
+     * Reads a single character,  as defined by {@link BufferedReader}'s readLine method,
+     * from the Arduino, casts it into a {@link char}, and returns it.
+     *
+     * @return char value read
+     */
+    public char receiveChar(){
+        char c = 0;
+        if (mBtHandler.getSocket() != null)
+            try {
+               c = (char) mBtHandler.getInputReader().read();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        return c;
+    }
+
+    /**
+     * Reads a line, as defined by {@link BufferedReader}'s readLine method, from the Arduino.
+     *
+     * @return {@link String} line read
+     */
+    public String receiveLine(){
+        String result = "";
+        if (mBtHandler.getSocket() != null)
+            try {
+                result = mBtHandler.getInputReader().readLine();
+            } catch (IOException ex) {
+                ex.printStackTrace();
+            }
+        return result;
+    }
+
 }