Androidusb转串口驱动开发pl2303hx由于pl2303xh(即pl2303xha)已停产，官方的demo仅支持pl2302hxd ra ea.不支持pl2303xha, 此文支持。
Android usb转串口驱动开发doliangzhe最近做了个平板与单片机的项目，由于使用的平板不支持串口，所以中间借助了usb-串口转换器(PL2303)。
这方面的资料可以说少之又少，几乎没有，我唯一能找到的就是usb-serial-for-android，一个国外的开源项目。
实现了一些主要的转换器的驱动，但是国内一般用得最多的还是PL2303。
我将usb-serial-for-android的驱动简化了下，成功的与串口调试工具通信了，能读，能写。
给大家分享下。
驱动源码：001.package com.example.android_usb;002.003.import java.io.ByteArrayOutputStream;004.import java.io.IOException;005.import ng.reflect.Method;006.007.import android.app.PendingIntent;008.import android.content.Context;009.import android.content.Intent;010.import bConstants;011.import bDevice;012.import bDeviceConnection;013.import bEndpoint;014.import bInterface;015.import bManager;016.import android.util.Log;017.import android.widget.Toast;018.019./**020.* PL2303串口驱动021.* @author pc022.*023.*/024.public class ProlificSerialDriver {025.private static final int USB_READ_TIMEOUT_MILLIS = 50 00;026.private static final int USB_WRITE_TIMEOUT_MILLIS = 3 000;027.private final Object mReadBufferLock = new Object();028.private final Object mWriteBufferLock = new Object();029.private byte[] buffer = new byte[4096];030.private ByteArrayOutputStream bufferOS = new ByteArr ayOutputStream();031.private Context context;032.private UsbEndpoint mReadEndpoint;033.private UsbEndpoint mWriteEndpoint;034.private UsbDeviceConnection connection;035.private UsbDevice usbDevice;037.public ProlificSerialDriver(Context context, UsbDevice u sbDevice){038.this.context = context;bDevice = usbDevice;040.}041./**042.* 安装043.* @param baudRate044.* @throws IOException045.*/046.public void setup(int baudRate) throws IOException{047.open();048.initPL2303Chip();049.ctrlOut(baudRate);050.}051.private void open() throws IOException{bManager usbManager = (UsbManager) context.get SystemService(B_SERVICE);053.//申请权限054.PendingIntent mPermissionIntent = PendingIntent.getB roadcast(context, 0, new Intent("com.prolific.pl2303hxdsimplete B_PERMISSION"), 0);bManager.requestPermission(usbDevice, mPermissio nIntent);bInterface usbInterface = usbDevice.getInterface(0);057.for (int i = 0; i < usbInterface.getEndpointCount(); ++i) {bEndpoint currentEndpoint = usbInterface.getEndpoi nt(i);060.switch (currentEndpoint.getAddress()) {061.case 0x83:062.mReadEndpoint = currentEndpoint;063.break;064.065.case 0x02:066.mWriteEndpoint = currentEndpoint;067.break;068.}069.}070.connection = usbManager.openDevice(usbDevice);071.connection.claimInterface(usbInterface, true);072.073.}074.private final void ctrlOut(int baudRate) throws IOExcepti on {075.//设置传输控制076.byte[] lineRequestData = new byte[7];077.078.lineRequestData[0] = (byte) (baudRate & 0xff);079.lineRequestData[1] = (byte) ((baudRate >> 8) & 0xff);080.lineRequestData[2] = (byte) ((baudRate >> 16) & 0xff);081.lineRequestData[3] = (byte) ((baudRate >> 24) & 0xff);082.083.lineRequestData[4] = 0;084.lineRequestData[5] = 0;085.lineRequestData[6] = (byte) 8;086.outControlTransfer(B_DIR_OUT | UsbC B_TYPE_CLASS | 0x01, 0x20, 0, 0, lineRequestData);088./**089.* 初始化芯片090.* @throws IOException091.*/092.private void initPL2303Chip() throws IOException{ 093.int mDeviceType = getDeviceType();094.vendorIn(0x8484, 0, 1);095.vendorOut(0x0404, 0, null);096.097.vendorIn(0x8484, 0, 1);098.vendorIn(0x8383, 0, 1);099.vendorIn(0x8484, 0, 1);100.101.vendorOut(0x0404, 1, null);102.vendorIn(0x8484, 0, 1);103.vendorIn(0x8383, 0, 1);104.105.vendorOut(0, 1, null);106.vendorOut(1, 0, null);107.vendorOut(2, (mDeviceType == 0) ? 0x44 : 0x24, null); 108.}109./**110.* 获得设备类型111.*/112.private int getDeviceType(){113.int mDeviceType = 0;114.try {115.if (usbDevice.getDeviceClass() == 0x02) {116.mDeviceType = 1;117.} else{118.Method getRawDescriptorsMethod = connection.getCl ass().getMethod("getRawDescriptors");119.byte[] rawDescriptors = (byte[]) getRawDescriptorsMet hod.invoke(connection);120.byte maxPacketSize0 = rawDescriptors[7];121.if (maxPacketSize0 == 64) {122.mDeviceType = 0;123.} else if ((usbDevice.getDeviceClass() == 0x00) || (usbDe vice.getDeviceClass() == 0xff)) {124.mDeviceType = 2;125.} else {126.mDeviceType = 0;127.}128.}129.}catch (Exception e) {130.// TODO Auto-generated catch block131.e.printStackTrace();132.}133.return mDeviceType;134.}135./**136.* 写137.* @param buf138.* @param wlength139.* @return140.*/141.public int write(byte[] buf, int wlength) {142.int offset = 0;143.byte[] write_buf = new byte[4096];144.synchronized (mWriteBufferLock) {145.while (offset < wlength) {146.int write_size = 4096;147.148.if (offset + write_size > wlength) {149.write_size = wlength - offset;150.}151.152.System.arraycopy(buf, offset, write_buf, 0, write_size);153.154.int actual_length = this.connection.bulkTransfer(this.m WriteEndpoint, write_buf, write_size, USB_WRITE_TIMEOUT_MILL IS);155.if (actual_length < 0) {156.return -1;157.}158.offset += actual_length;159.}160.}161.return offset;162.}163./**164.* 读取165.* @param timeoutMillis166.* @throws IOException167.*/168.public byte[] read() throws IOException {169.synchronized (mReadBufferLock) {170.try {171.bufferOS.reset();172.int number = 0;173.while(number != -1){174.number = connection.bulkTransfer(mReadEndpoint, buf fer, buffer.length, USB_READ_TIMEOUT_MILLIS);175.MainActivity.showMessage("number:"+number);176.bufferOS.write(buffer, 0, number);177.}178.} catch (Exception e) {179.e.printStackTrace();180.}181.}182.return bufferOS.toByteArray();183.}184./**185.* 关闭资源186.*/187.public void close(){188.try {189.if (connection == null) {190.return ;191.}192.connection.releaseInterface(bDevice.getInterface( 0));193.} catch (Exception e) {194.e.printStackTrace();195.}196.}197./**198.* 输出的传输199.* @throws IOException200.*/201.private final void outControlTransfer(int requestType, in t request, int value, int index, byte[] data) throws IOException { 202.int length = (data == null) ? 0 : data.length;203.int result = connection.controlTransfer(requestType, req uest, value, index, data, length, USB_WRITE_TIMEOUT_MILLIS);204.if (result != length) {205.throw new IOException(String.format("ControlTransfer with value 0x%x failed: %d", value, result));206.}207.}208./**209.* 输入的传输210.* @throws IOException211.*/212.private final byte[] inControlTransfer(int requestType, int request, int value, int index, int length) throws IOException { 213.byte[] buffer = new byte[length];214.int result = connection.controlTransfer(requestType, req uest, value, index, buffer, length, USB_READ_TIMEOUT_MILLIS);215.if (result != length) {216.throw new IOException(String.format("ControlTransfer with value 0x%x failed: %d", value, result));217.}218.return buffer;219.}220./**221.* 写设备控制222.*/223.private final byte[] vendorIn(int value, int index, int length)throws IOException {224.return inControlTransfer(B_DIR_IN | Us B_TYPE_VENDOR, 0x01, value, index, length);225.}226./**227.* 读设备控制228.*/229.private final void vendorOut(int value, int index, byte[] d ata)throws IOException {230.outControlTransfer(B_DIR_OUT | UsbC B_TYPE_VENDOR, 0x01, value, index, data);231.}232.}。
