Update Configs, Clean Codes and Add Readmes

AndroidApp/app/build.gradle

@@ -1,15 +1,18 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.3"
+    compileSdkVersion 28
+    buildToolsVersion "30.0.3"
     defaultConfig {
         applicationId "io.github.introml.activityrecognition"
         minSdkVersion 21
-        targetSdkVersion 25
+        targetSdkVersion 28
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        ndk {
+            abiFilters "armeabi-v7a"
+        }
     }
     buildTypes {
         release {
@@ -25,11 +28,11 @@ android {
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
+    implementation 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'
-    compile 'com.android.support.constraint:constraint-layout:1.0.2'
-    testCompile 'junit:junit:4.12'
+    implementation 'com.android.support:appcompat-v7:28.0.0'
+    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
+    testImplementation 'junit:junit:4.12'
 }

AndroidApp/app/src/main/java/io/github/introml/activityrecognition/MainActivity.java

@@ -34,7 +34,7 @@ public class MainActivity extends AppCompatActivity implements SensorEventListen
     private float[] results;
     private TensorFlowClassifier classifier;
 
-    private String[] labels = {"Downstairs", "Jogging", "Sitting", "Standing", "Upstairs", "Walking"};
+    private final String[] labels = {"Downstairs", "Jogging", "Sitting", "Standing", "Upstairs", "Walking"};
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -44,12 +44,12 @@ protected void onCreate(Bundle savedInstanceState) {
         y = new ArrayList<>();
         z = new ArrayList<>();
 
-        downstairsTextView = (TextView) findViewById(R.id.downstairs_prob);
-        joggingTextView = (TextView) findViewById(R.id.jogging_prob);
-        sittingTextView = (TextView) findViewById(R.id.sitting_prob);
-        standingTextView = (TextView) findViewById(R.id.standing_prob);
-        upstairsTextView = (TextView) findViewById(R.id.upstairs_prob);
-        walkingTextView = (TextView) findViewById(R.id.walking_prob);
+        downstairsTextView = findViewById(R.id.downstairs_prob);
+        joggingTextView = findViewById(R.id.jogging_prob);
+        sittingTextView = findViewById(R.id.sitting_prob);
+        standingTextView = findViewById(R.id.standing_prob);
+        upstairsTextView = findViewById(R.id.upstairs_prob);
+        walkingTextView = findViewById(R.id.walking_prob);
 
         classifier = new TensorFlowClassifier(getApplicationContext());
 
@@ -112,12 +112,12 @@ private void activityPrediction() {
 
             results = classifier.predictProbabilities(toFloatArray(data));
 
-            downstairsTextView.setText(Float.toString(round(results[0], 2)));
-            joggingTextView.setText(Float.toString(round(results[1], 2)));
-            sittingTextView.setText(Float.toString(round(results[2], 2)));
-            standingTextView.setText(Float.toString(round(results[3], 2)));
-            upstairsTextView.setText(Float.toString(round(results[4], 2)));
-            walkingTextView.setText(Float.toString(round(results[5], 2)));
+            downstairsTextView.setText(Float.toString(round(results[0])));
+            joggingTextView.setText(Float.toString(round(results[1])));
+            sittingTextView.setText(Float.toString(round(results[2])));
+            standingTextView.setText(Float.toString(round(results[3])));
+            upstairsTextView.setText(Float.toString(round(results[4])));
+            walkingTextView.setText(Float.toString(round(results[5])));
 
             x.clear();
             y.clear();
@@ -135,9 +135,9 @@ private float[] toFloatArray(List<Float> list) {
         return array;
     }
 
-    private static float round(float d, int decimalPlace) {
+    private static float round(float d) {
         BigDecimal bd = new BigDecimal(Float.toString(d));
-        bd = bd.setScale(decimalPlace, BigDecimal.ROUND_HALF_UP);
+        bd = bd.setScale(2, BigDecimal.ROUND_HALF_UP);
         return bd.floatValue();
     }
 

AndroidApp/app/src/main/java/io/github/introml/activityrecognition/TensorFlowClassifier.java

@@ -10,9 +10,9 @@ public class TensorFlowClassifier {
         System.loadLibrary("tensorflow_inference");
     }
 
-    private TensorFlowInferenceInterface inferenceInterface;
+    private final TensorFlowInferenceInterface inferenceInterface;
     private static final String MODEL_FILE = "file:///android_asset/frozen_model.pb";
-//    private static final String MODEL_FILE = "file:///android_asset/frozen_har.pb";
+    //    private static final String MODEL_FILE = "file:///android_asset/frozen_har.pb";
     private static final String INPUT_NODE = "inputs";
     private static final String[] OUTPUT_NODES = {"y_"};
     private static final String OUTPUT_NODE = "y_";

AndroidApp/app/src/main/res/layout/activity_main.xml

@@ -5,7 +5,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
-    <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    <TableLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:background="#ededed"

AndroidApp/build.gradle

@@ -2,10 +2,13 @@
 
 buildscript {
     repositories {
+        maven { url 'https://maven.aliyun.com/repository/google/' }
+        maven { url 'https://maven.aliyun.com/repository/jcenter/'}
         jcenter()
+        google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.1'
+        classpath 'com.android.tools.build:gradle:4.1.1'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -14,7 +17,10 @@ buildscript {
 
 allprojects {
     repositories {
+        maven { url 'https://maven.aliyun.com/repository/google/' }
+        maven { url 'https://maven.aliyun.com/repository/jcenter/'}
         jcenter()
+        google()
     }
 }
 

AndroidApp/gradle/wrapper/gradle-wrapper.properties

@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.5-all.zip

README.md

@@ -11,3 +11,34 @@ Interested in deeper understanding of Machine Learning algorithms? Implement the
 </a>
 
 <a href="https://leanpub.com/hmls" target="_blank">Read the book here</a>
+
+
+
+---
+
+### My Environments (2021)
+
+- Android SDK Platform 28 (Android 9.0 Pie)
+- Android SDK Build-Tools 30.0.3 (Higher version Supports lower version)
+- a Android *Phone* with Android 10 OS (Support lower SDK built apps I guess)
+
+
+
+**It works fine on my phone!**
+
+<img src="assets/image-20210114132032334.png" alt="image-20210114132032334" style="zoom:50%;" />
+
+### Changes Should be Made to Run Locally
+
+- `gradle-wrapper.properties`
+  - To fit your own `gradle` version. 
+  - BTW, my written version works fine, you can let it run.
+- `build.gradle`
+  - Top-level
+  - Change to your local **repositories**, I used `aliyun`
+- `build.gradle`
+  - App-level
+  - `compileSdkVersion`
+  - `buildToolsVersion`
+  - `targetSdkVersion`
+