android 串口通信

FT311D接口芯片为Android手机或平板电脑提供了USB转外部UART、GPIO、PWM、I2C、SPI硬件接口功能。
因为用的是这种串口，也就得用他对应的类

FT311UARTInterface.java 接口类 直接用

//User must modify the below package with their package namepackage com.example.chuankoudemo;import java.io.FileDescriptor;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import Database.Global;import android.app.Activity;import android.app.PendingIntent;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.content.SharedPreferences;import android.hardware.usb.UsbAccessory;import android.hardware.usb.UsbManager;import android.os.Bundle;import android.os.ParcelFileDescriptor;import android.util.Log;import android.widget.Toast;/****************************** FT311 GPIO interface class ******************************************/public abstract class FT311UARTInterface extends Activity {    private static final String ACTION_USB_PERMISSION = "com.UARTTest.USB_PERMISSION";    public UsbManager usbmanager;    public UsbAccessory usbaccessory;    public PendingIntent mPermissionIntent;    public ParcelFileDescriptor filedescriptor = null;    public FileInputStream inputstream = null;    public FileOutputStream outputstream = null;    public boolean mPermissionRequestPending = false;    public read_thread readThread;    private byte[] writeusbdata;    //public byte[] readBuffer; /* circular buffer */    private byte status;    //final int maxnumbytes = 1024;    final int maxnumLimit=256;    public boolean datareceived = false;    public boolean READ_ENABLE = false;    public boolean accessory_attached = false;    public static String ManufacturerString = "mManufacturer=FTDI";    public static String ModelString1 = "mModel=FTDIUARTDemo";    public static String ModelString2 = "mModel=Android Accessory FT312D";    public static String VersionString = "mVersion=1.0";    public SharedPreferences intsharePrefSettings;    @Override    protected void onCreate(Bundle savedInstanceState) {        // TODO Auto-generated method stub        super.onCreate(savedInstanceState);        Global.context = this;        intsharePrefSettings = null;// sharePrefSettings;        writeusbdata = new byte[maxnumLimit];        /* 128(make it 256, but looks like bytes should be enough) */        //readBuffer = new byte[maxnumbytes];        usbmanager = (UsbManager) this.getSystemService(Context.USB_SERVICE);        // Log.d("LED", "usbmanager" +usbmanager);        mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(                ACTION_USB_PERMISSION), 0);        IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);        filter.addAction(UsbManager.ACTION_USB_ACCESSORY_DETACHED);        this.registerReceiver(mUsbReceiver, filter);    }    public void SetConfig(int baud, byte dataBits, byte stopBits, byte parity,            byte flowControl) {        //配置信息写到前8个byte        /* prepare the baud rate buffer */        writeusbdata[0] = (byte) baud;        writeusbdata[1] = (byte) (baud >> 8);        writeusbdata[2] = (byte) (baud >> 16);        writeusbdata[3] = (byte) (baud >> 24);        /* data bits */        writeusbdata[4] = dataBits;        /* stop bits */        writeusbdata[5] = stopBits;        /* parity */        writeusbdata[6] = parity;        /* flow control */        writeusbdata[7] = flowControl;        /* send the UART configuration packet */        SendPacket((int) 8);    }    /* write data */    public byte SendData(int numBytes, byte[] buffer) {        status = 0x00; /* success by default */        /*         * if num bytes are more than maximum limit         */        if (numBytes < 1) {            /* return the status with the error in the command */            return status;        }        /* check for maximum limit */        if (numBytes > maxnumLimit) {            numBytes = maxnumLimit;        }        /* prepare the packet to be sent */        for (int count = 0; count < numBytes; count++) {            writeusbdata[count] = buffer[count];        }        if (numBytes != 64) {            SendPacket(numBytes);        } else {            byte temp = writeusbdata[63];            SendPacket(63);            writeusbdata[0] = temp;            SendPacket(1);        }        return status;    }    /* method to send on USB */    private void SendPacket(int numBytes) {        try {            if (outputstream != null) {                outputstream.write(writeusbdata, 0, numBytes);            }        } catch (IOException e) {            e.printStackTrace();        }    }    /* resume accessory */    public int ResumeAccessory() {        // Intent intent = getIntent();        if (inputstream != null && outputstream != null) {            return 1;        }        UsbAccessory[] accessories = usbmanager.getAccessoryList();        if (accessories != null) {            Toast.makeText(Global.context, "Accessory Attached",                    Toast.LENGTH_SHORT).show();        } else {            // return 2 for accessory detached case            accessory_attached = false;            return 2;        }        UsbAccessory accessory = (accessories == null ? null : accessories[0]);        if (accessory != null) {            if (-1 == accessory.toString().indexOf(ManufacturerString)) {                Toast.makeText(Global.context, "Manufacturer is not matched!",                        Toast.LENGTH_SHORT).show();                return 1;            }            if (-1 == accessory.toString().indexOf(ModelString1)                    && -1 == accessory.toString().indexOf(ModelString2)) {                Toast.makeText(Global.context, "Model is not matched!",                        Toast.LENGTH_SHORT).show();                return 1;            }            if (-1 == accessory.toString().indexOf(VersionString)) {                Toast.makeText(Global.context, "Version is not matched!",                        Toast.LENGTH_SHORT).show();                return 1;            }            Toast.makeText(Global.context,                    "Manufacturer, Model & Version are matched!",                    Toast.LENGTH_SHORT).show();            accessory_attached = true;            if (usbmanager.hasPermission(accessory)) {                OpenAccessory(accessory);            } else {                synchronized (mUsbReceiver) {                    if (!mPermissionRequestPending) {                        Toast.makeText(Global.context,                                "Request USB Permission", Toast.LENGTH_SHORT)                                .show();                        usbmanager.requestPermission(accessory,                                mPermissionIntent);                        mPermissionRequestPending = true;                    }                }            }        } else {        }        return 0;    }    /* destroy accessory */    public void DestroyAccessory(boolean bConfiged) {        if (true == bConfiged) {            READ_ENABLE = false; // set false condition for handler_thread to                                    // exit waiting data loop            writeusbdata[0] = 0; // send dummy data for instream.read going            SendPacket(1);        } else {            SetConfig(9600, (byte) 1, (byte) 8, (byte) 0, (byte) 0); // send                                                                        // default                                                                        // setting                                                                        // data                                                                        // for                                                                        // config            try {                Thread.sleep(10);            } catch (Exception e) {            }            READ_ENABLE = false; // set false condition for handler_thread to                                    // exit waiting data loop            writeusbdata[0] = 0; // send dummy data for instream.read going            SendPacket(1);            if (true == accessory_attached) {                saveDefaultPreference();            }        }        try {            Thread.sleep(10);        } catch (Exception e) {        }        CloseAccessory();    }    /********************* helper routines *************************************************/    public void OpenAccessory(UsbAccessory accessory) {        filedescriptor = usbmanager.openAccessory(accessory);        if (filedescriptor != null) {            usbaccessory = accessory;            FileDescriptor fd = filedescriptor.getFileDescriptor();            inputstream = new FileInputStream(fd);            outputstream = new FileOutputStream(fd);            /* check if any of them are null */            if (inputstream == null || outputstream == null) {                return;            }            if (READ_ENABLE == false) {                READ_ENABLE = true;                readThread = new read_thread(inputstream);                readThread.start();            }        }    }    private void CloseAccessory() {        try {            if (filedescriptor != null)                filedescriptor.close();        } catch (IOException e) {        }        try {            if (inputstream != null)                inputstream.close();        } catch (IOException e) {        }        try {            if (outputstream != null)                outputstream.close();        } catch (IOException e) {        }        /* FIXME, add the notfication also to close the application */        filedescriptor = null;        inputstream = null;        outputstream = null;        System.exit(0);    }    protected void saveDetachPreference() {        if (intsharePrefSettings != null) {            intsharePrefSettings.edit().putString("configed", "FALSE").commit();        }    }    protected void saveDefaultPreference() {        if (intsharePrefSettings != null) {            intsharePrefSettings.edit().putString("configed", "TRUE").commit();            intsharePrefSettings.edit().putInt("baudRate", 9600).commit();            intsharePrefSettings.edit().putInt("stopBit", 1).commit();            intsharePrefSettings.edit().putInt("dataBit", 8).commit();            intsharePrefSettings.edit().putInt("parity", 0).commit();            intsharePrefSettings.edit().putInt("flowControl", 0).commit();        }    }    /*********** USB broadcast receiver *******************************************/    private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {        @Override        public void onReceive(Context context, Intent intent) {            String action = intent.getAction();            if (ACTION_USB_PERMISSION.equals(action)) {                synchronized (this) {                    UsbAccessory accessory = (UsbAccessory) intent                            .getParcelableExtra(UsbManager.EXTRA_ACCESSORY);                    if (intent.getBooleanExtra(                            UsbManager.EXTRA_PERMISSION_GRANTED, false)) {                        Toast.makeText(Global.context, "Allow USB Permission",                                Toast.LENGTH_SHORT).show();                        OpenAccessory(accessory);                    } else {                        Toast.makeText(Global.context, "Deny USB Permission",                                Toast.LENGTH_SHORT).show();                        Log.d("LED", "permission denied for accessory "                                + accessory);                    }                    mPermissionRequestPending = false;                }            } else if (UsbManager.ACTION_USB_ACCESSORY_DETACHED.equals(action)) {                saveDetachPreference();                DestroyAccessory(true);            } else {                Log.d("LED", "....");            }        }    };    /* usb input data handler */    private class read_thread extends Thread {        FileInputStream instream;        read_thread(FileInputStream stream) {            instream = stream;        }        @Override        public void run() {            super.run();            while (READ_ENABLE == true && !isInterrupted()) {                byte[] usb = new byte[1024];                try {                    if (instream == null) {                        return;                    }                    int readcount = instream.read(usb);                    if (readcount > 0) {                        onDataReceived(usb, readcount);                    }                } catch (IOException e) {                    e.printStackTrace();                    return;                }            }        }    }    protected abstract void onDataReceived(final byte[] buffer, final int size);}

用的时候 主类extends FT311UARTInterface一下

MainActivity.java

package com.example.chuankoudemo;//import java.io.UnsupportedEncodingException;//import java.util.ArrayList;import Database.Global;import android.annotation.SuppressLint;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends FT311UARTInterface implements OnClickListener{    private long main_time = Global.threadPeriod;    protected CharSequence sError;    protected boolean reflag;    protected EditText etReceive=null;    private Button btSend=null;    private EditText etSend=null;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        // 初始化所有控件        allinit();        System.out.println("start");        new Thread(new Homethread()).start();    }    private void allinit() {// 初始化监听以及控件定义        etReceive=(EditText)findViewById(R.id.etReceive);        etSend=(EditText)findViewById(R.id.etSend);        btSend=(Button)findViewById(R.id.btSend);        btSend.setOnClickListener(this);    }    @Override    protected void onResume() {        super.onResume();        ResumeAccessory();        SetConfig(115200, (byte) 8, (byte) 1, (byte) 0, (byte) 0);    }    @Override    protected void onPause() {        super.onPause();    }    @Override    protected void onDestroy() {        super.onDestroy();        DestroyAccessory(true);        android.os.Process.killProcess(android.os.Process.myPid());    }    @Override    public boolean onOptionsItemSelected(MenuItem item) {// end        return true;    }    /**     * @Fields handler : 用于线程间通信     */    @SuppressLint("HandlerLeak")    public Handler handler = new Handler() {        @Override        public void handleMessage(Message msg) {            byte[] usbdata = new byte[64];            switch (msg.what) {            case 1:// 回复                Toast.makeText(getApplicationContext(), Global.sendCMD, 30).show();                usbdata = Global.sendCMD.getBytes();                int size = usbdata.length;                SendData(size, usbdata);                break;            case 6:                Toast.makeText(getApplicationContext(), sError, 30).show();            default:                break;            }            super.handleMessage(msg);        }    };    class Homethread implements Runnable {        long start = 0;        long end = 0;        String text = "";        @Override        public void run() {            SetConfig(115200, (byte) 8, (byte) 1, (byte) 0, (byte) 0);            while (!Thread.interrupted()) {                start=System.currentTimeMillis();                System.out.println("HomeThread");                Message message = new Message();                //处理接受命令                end = System.currentTimeMillis();                try {                    if (end - start < main_time) {                        Thread.sleep(main_time - (end - start));                    }                } catch (InterruptedException e) {                    e.printStackTrace();                }            }        }    }    @Override    protected void onDataReceived(final byte[] buffer, final int size) {        runOnUiThread(new Runnable() {            public void run() {                String a = new String(buffer, 0, size);                    //usbBuffer.append(a);                    etReceive.append(a,0,size);                             }        });    }    @Override    public void onClick(View v) {        // TODO        if(v.getId()==R.id.btSend){            Global.sendCMD=etSend.getText().toString();            Message message=new Message();            message.what=1;            this.handler.sendMessage(message);        }    }}

main里面用到我在global里定义的几个参数
Global.java

public class Global {    public static Context context = null;    public static long threadPeriod = 1000;// 子线程周期    public static String sendCMD = "";// 要发送的命令    public static boolean sendSwitch = false;// 发送命令开关    public static synchronized void setSendSwitch(boolean set) {        Global.sendSwitch = set;    }    public static boolean canSend(){        return sendSwitch;    }}

现在程序还不能直接用
还要在AndroidManifest申请权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" >    </uses-permission>

再在对应的activity中添加

<intent-filter>                <action android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED" />            </intent-filter>            <meta-data                android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED"                android:resource="@xml/accessory_filter" >            </meta-data>

accessory_filter.xml

<?xml version="1.0" encoding="utf-8"?><resources>        <usb-accessory model="FTDIUARTDemo" manufacturer="FTDI" version="1.0"/>    <usb-accessory model="Android Accessory FT312D" manufacturer="FTDI" version="1.0"/></resources>