Android提高之模擬信號(hào)示波器的實(shí)現(xiàn)
前面簡(jiǎn)單地介紹了Android程序開(kāi)發(fā)中AudioRecord和AudioTrack的使用,這次再結(jié)合SurfaceView實(shí)現(xiàn)一個(gè)Android版的手機(jī)模擬信號(hào)示波器。最近物聯(lián)網(wǎng)炒得很火,作為手機(jī)軟件開(kāi)發(fā)者,如何在不修改手機(jī)硬件電路的前提下實(shí)現(xiàn)與第三方傳感器結(jié)合呢?麥克風(fēng)就是一個(gè)很好的ADC接口,通過(guò)麥克風(fēng)與第三方傳感器結(jié)合,再在軟件里對(duì)模擬信號(hào)做相應(yīng)的處理,就可以提供更豐富的傳感化應(yīng)用。
先來(lái)看看本文程序運(yùn)行的效果圖(屏幕錄像截圖的速度較慢,真機(jī)實(shí)際運(yùn)行起來(lái)會(huì)很流暢):
本文程序使用8000hz的采樣率,對(duì)X軸方向繪圖的實(shí)時(shí)性要求較高,如果不降低X軸的分辨率,程序的實(shí)時(shí)性較差,因此程序?qū)軸數(shù)據(jù)縮小區(qū)間為8倍~16倍。由于采用16位采樣,因此Y軸數(shù)據(jù)的高度相對(duì)于手機(jī)屏幕來(lái)說(shuō)也偏大,程序也對(duì)Y軸數(shù)據(jù)做縮小,區(qū)間為1倍~10倍。在SurfaceView的OnTouchListener方法里加入了波形基線(xiàn)的位置調(diào)節(jié),直接在SurfaceView控件上觸摸即可控制整體波形偏上或偏下顯示。
main.xml源碼如下:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <LinearLayout android:id="@+id/LinearLayout01" android:layout_height="wrap_content" android:layout_width="fill_parent" android:orientation="horizontal"> <Button android:layout_height="wrap_content" android:id="@+id/btnStart" android:text="開(kāi)始" android:layout_width="80dip"></Button> <Button android:layout_height="wrap_content" android:text="停止" android:id="@+id/btnExit" android:layout_width="80dip"></Button> <ZoomControls android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/zctlX"></ZoomControls> <ZoomControls android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/zctlY"></ZoomControls> </LinearLayout> <SurfaceView android:id="@+id/SurfaceView01" android:layout_height="fill_parent" android:layout_width="fill_parent"></SurfaceView> </LinearLayout>
ClsOscilloscope.java是實(shí)現(xiàn)示波器的類(lèi)庫(kù),包含AudioRecord操作線(xiàn)程和SurfaceView繪圖線(xiàn)程的實(shí)現(xiàn),兩個(gè)線(xiàn)程同步操作,代碼如下:
package com.testOscilloscope; import java.util.ArrayList; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Rect; import android.media.AudioRecord; import android.view.SurfaceView; public class ClsOscilloscope { private ArrayList<short[]> inBuf = new ArrayList<short[]>(); private boolean isRecording = false;// 線(xiàn)程控制標(biāo)記 /** * X軸縮小的比例 */ public int rateX = 4; /** * Y軸縮小的比例 */ public int rateY = 4; /** * Y軸基線(xiàn) */ public int baseLine = 0; /** * 初始化 */ public void initOscilloscope(int rateX, int rateY, int baseLine) { this.rateX = rateX; this.rateY = rateY; this.baseLine = baseLine; } /** * 開(kāi)始 * * @param recBufSize * AudioRecord的MinBufferSize */ public void Start(AudioRecord audioRecord, int recBufSize, SurfaceView sfv, Paint mPaint) { isRecording = true; new RecordThread(audioRecord, recBufSize).start();// 開(kāi)始錄制線(xiàn)程 new DrawThread(sfv, mPaint).start();// 開(kāi)始繪制線(xiàn)程 } /** * 停止 */ public void Stop() { isRecording = false; inBuf.clear();// 清除 } /** * 負(fù)責(zé)從MIC保存數(shù)據(jù)到inBuf * * @author GV * */ class RecordThread extends Thread { private int recBufSize; private AudioRecord audioRecord; public RecordThread(AudioRecord audioRecord, int recBufSize) { this.audioRecord = audioRecord; this.recBufSize = recBufSize; } public void run() { try { short[] buffer = new short[recBufSize]; audioRecord.startRecording();// 開(kāi)始錄制 while (isRecording) { // 從MIC保存數(shù)據(jù)到緩沖區(qū) int bufferReadResult = audioRecord.read(buffer, 0, recBufSize); short[] tmpBuf = new short[bufferReadResult / rateX]; for (int i = 0, ii = 0; i < tmpBuf.length; i++, ii = i * rateX) { tmpBuf[i] = buffer[ii]; } synchronized (inBuf) {// inBuf.add(tmpBuf);// 添加數(shù)據(jù) } } audioRecord.stop(); } catch (Throwable t) { } } }; /** * 負(fù)責(zé)繪制inBuf中的數(shù)據(jù) * * @author GV * */ class DrawThread extends Thread { private int oldX = 0;// 上次繪制的X坐標(biāo) private int oldY = 0;// 上次繪制的Y坐標(biāo) private SurfaceView sfv;// 畫(huà)板 private int X_index = 0;// 當(dāng)前畫(huà)圖所在屏幕X軸的坐標(biāo) private Paint mPaint;// 畫(huà)筆 public DrawThread(SurfaceView sfv, Paint mPaint) { this.sfv = sfv; this.mPaint = mPaint; } public void run() { while (isRecording) { ArrayList<short[]> buf = new ArrayList<short[]>(); synchronized (inBuf) { if (inBuf.size() == 0) continue; buf = (ArrayList<short[]>) inBuf.clone();// 保存 inBuf.clear();// 清除 } for (int i = 0; i < buf.size(); i++) { short[] tmpBuf = buf.get(i); SimpleDraw(X_index, tmpBuf, rateY, baseLine);// 把緩沖區(qū)數(shù)據(jù)畫(huà)出來(lái) X_index = X_index + tmpBuf.length; if (X_index > sfv.getWidth()) { X_index = 0; } } } } /** * 繪制指定區(qū)域 * * @param start * X軸開(kāi)始的位置(全屏) * @param buffer * 緩沖區(qū) * @param rate * Y軸數(shù)據(jù)縮小的比例 * @param baseLine * Y軸基線(xiàn) */ void SimpleDraw(int start, short[] buffer, int rate, int baseLine) { if (start == 0) oldX = 0; Canvas canvas = sfv.getHolder().lockCanvas( new Rect(start, 0, start + buffer.length, sfv.getHeight()));// 關(guān)鍵:獲取畫(huà)布 canvas.drawColor(Color.BLACK);// 清除背景 int y; for (int i = 0; i < buffer.length; i++) {// 有多少畫(huà)多少 int x = i + start; y = buffer[i] / rate + baseLine;// 調(diào)節(jié)縮小比例,調(diào)節(jié)基準(zhǔn)線(xiàn) canvas.drawLine(oldX, oldY, x, y, mPaint); oldX = x; oldY = y; } sfv.getHolder().unlockCanvasAndPost(canvas);// 解鎖畫(huà)布,提交畫(huà)好的圖像 } } }
testOscilloscope.java是主程序,控制UI和ClsOscilloscope,代碼如下:
package com.testOscilloscope; import android.app.Activity; import android.graphics.Color; import android.graphics.Paint; import android.media.AudioFormat; import android.media.AudioRecord; import android.media.MediaRecorder; import android.os.Bundle; import android.view.MotionEvent; import android.view.SurfaceView; import android.view.View; import android.view.View.OnTouchListener; import android.widget.Button; import android.widget.ZoomControls; public class testOscilloscope extends Activity { /** Called when the activity is first created. */ Button btnStart,btnExit; SurfaceView sfv; ZoomControls zctlX,zctlY; ClsOscilloscope clsOscilloscope=new ClsOscilloscope(); static final int frequency = 8000;//分辨率 static final int channelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_MONO; static final int audioEncoding = AudioFormat.ENCODING_PCM_16BIT; static final int xMax = 16;//X軸縮小比例最大值,X軸數(shù)據(jù)量巨大,容易產(chǎn)生刷新延時(shí) static final int xMin = 8;//X軸縮小比例最小值 static final int yMax = 10;//Y軸縮小比例最大值 static final int yMin = 1;//Y軸縮小比例最小值 int recBufSize;//錄音最小buffer大小 AudioRecord audioRecord; Paint mPaint; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //錄音組件 recBufSize = AudioRecord.getMinBufferSize(frequency, channelConfiguration, audioEncoding); audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, frequency, channelConfiguration, audioEncoding, recBufSize); //按鍵 btnStart = (Button) this.findViewById(R.id.btnStart); btnStart.setOnClickListener(new ClickEvent()); btnExit = (Button) this.findViewById(R.id.btnExit); btnExit.setOnClickListener(new ClickEvent()); //畫(huà)板和畫(huà)筆 sfv = (SurfaceView) this.findViewById(R.id.SurfaceView01); sfv.setOnTouchListener(new TouchEvent()); mPaint = new Paint(); mPaint.setColor(Color.GREEN);// 畫(huà)筆為綠色 mPaint.setStrokeWidth(1);// 設(shè)置畫(huà)筆粗細(xì) //示波器類(lèi)庫(kù) clsOscilloscope.initOscilloscope(xMax/2, yMax/2, sfv.getHeight()/2); //縮放控件,X軸的數(shù)據(jù)縮小的比率高些 zctlX = (ZoomControls)this.findViewById(R.id.zctlX); zctlX.setOnZoomInClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(clsOscilloscope.rateX>xMin) clsOscilloscope.rateX--; setTitle("X軸縮小"+String.valueOf(clsOscilloscope.rateX)+"倍" +","+"Y軸縮小"+String.valueOf(clsOscilloscope.rateY)+"倍"); } }); zctlX.setOnZoomOutClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(clsOscilloscope.rateX<xMax) clsOscilloscope.rateX++; setTitle("X軸縮小"+String.valueOf(clsOscilloscope.rateX)+"倍" +","+"Y軸縮小"+String.valueOf(clsOscilloscope.rateY)+"倍"); } }); zctlY = (ZoomControls)this.findViewById(R.id.zctlY); zctlY.setOnZoomInClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(clsOscilloscope.rateY>yMin) clsOscilloscope.rateY--; setTitle("X軸縮小"+String.valueOf(clsOscilloscope.rateX)+"倍" +","+"Y軸縮小"+String.valueOf(clsOscilloscope.rateY)+"倍"); } }); zctlY.setOnZoomOutClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(clsOscilloscope.rateY<yMax) clsOscilloscope.rateY++; setTitle("X軸縮小"+String.valueOf(clsOscilloscope.rateX)+"倍" +","+"Y軸縮小"+String.valueOf(clsOscilloscope.rateY)+"倍"); } }); } @Override protected void onDestroy() { super.onDestroy(); android.os.Process.killProcess(android.os.Process.myPid()); } /** * 按鍵事件處理 * @author GV * */ class ClickEvent implements View.OnClickListener { @Override public void onClick(View v) { if (v == btnStart) { clsOscilloscope.baseLine=sfv.getHeight()/2; clsOscilloscope.Start(audioRecord,recBufSize,sfv,mPaint); } else if (v == btnExit) { clsOscilloscope.Stop(); } } } /** * 觸摸屏動(dòng)態(tài)設(shè)置波形圖基線(xiàn) * @author GV * */ class TouchEvent implements OnTouchListener{ @Override public boolean onTouch(View v, MotionEvent event) { clsOscilloscope.baseLine=(int)event.getY(); return true; } } }
希望本文實(shí)例對(duì)于讀者進(jìn)行Android項(xiàng)目開(kāi)發(fā)能起到一定的借鑒與幫助作用。
- Android9.0 SystemUI 網(wǎng)絡(luò)信號(hào)欄定制修改的流程解析
- Android自定義View展示W(wǎng)ifi信號(hào)強(qiáng)弱指示方法示例
- Android Init進(jìn)程對(duì)信號(hào)的處理流程詳細(xì)介紹
- Android手機(jī)信號(hào)強(qiáng)度檢測(cè)詳細(xì)介紹
- android 獲取手機(jī)GSM/CDMA信號(hào)信息,并獲得基站信息的方法
- Android 模擬信號(hào)示波器示例代碼
- Android獲取當(dāng)前已連接的wifi信號(hào)強(qiáng)度的方法
- Android實(shí)現(xiàn)信號(hào)強(qiáng)度監(jiān)聽(tīng)的方法
- android wifi信號(hào)強(qiáng)度等級(jí)區(qū)分的修改介紹
- Android獲取移動(dòng)網(wǎng)絡(luò)信號(hào)強(qiáng)度的方法
相關(guān)文章
Android抓取CSDN首頁(yè)極客頭條內(nèi)容完整實(shí)例
這篇文章主要介紹了Android抓取CSDN首頁(yè)極客頭條內(nèi)容完整實(shí)例,具有一定借鑒價(jià)值,需要的朋友可以參考下2018-01-01RelativeLayout(相對(duì)布局)用法實(shí)例講解
在本文里小編給大家分享了關(guān)于RelativeLayout(相對(duì)布局)用法知識(shí)點(diǎn)以及對(duì)應(yīng)的實(shí)例內(nèi)容,需要的朋友們學(xué)習(xí)下。2019-02-02Android ListView分頁(yè)功能實(shí)現(xiàn)方法
這篇文章主要為大家詳細(xì)介紹了Android ListView分頁(yè)功能的實(shí)現(xiàn)方法,具有一定的參考價(jià)值,感興趣的小伙伴們可以參考一下2016-05-05Qt6.5.3?Android環(huán)境配置的實(shí)現(xiàn)
本文主要介紹了Qt6.5.3?Android環(huán)境配置的實(shí)現(xiàn),文中通過(guò)圖文介紹的非常詳細(xì),對(duì)大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值,需要的朋友們下面隨著小編來(lái)一起學(xué)習(xí)學(xué)習(xí)吧2024-01-01Android中ListView設(shè)置靜態(tài)數(shù)據(jù)的方法
這篇文章主要介紹了Android中ListView設(shè)置靜態(tài)數(shù)據(jù)的方法,如何為L(zhǎng)istView設(shè)置靜態(tài)數(shù)據(jù),感興趣的小伙伴們可以參考一下2015-12-12Android編程UI設(shè)計(jì)之GridView和ImageView的用法
這篇文章主要介紹了Android編程UI設(shè)計(jì)之GridView和ImageView的用法,結(jié)合實(shí)例形式較為詳細(xì)的分析了Android中GridView和ImageView組件的相關(guān)方法使用技巧,需要的朋友可以參考下2016-01-01詳解Android WebView的input上傳照片的兼容問(wèn)題
本篇文章主要介紹了詳解Android WebView的input上傳照片的兼容問(wèn)題,非常具有實(shí)用價(jià)值,需要的朋友可以參考下2017-08-08