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android操作串口

發布時間: 2024-11-24 00:56:02

❶ 一般android系統的手機硬體上支持串口嗎android系統有沒有串口...

串口API肯定是有的,打開設備後通過文件操作符來read和write。但是,手機上沒有串口啊。和PC通訊是通過ADB用usb來做的。
也可以通過BT模塊來通訊,車載設備不都是這么做的么 .

❷ 如何開放android的串口許可權

要調用串口,肯定是要用到JNI的,而且要有打開對應串口設備的許可權
至於是不是通過USB轉的,沒啥關系,因為USB轉串口的驅動已經把USB的特徵封裝了,就當它是一個純串口操作就行
android-serialport-api也是用的JNI,要想知道能不能用,裝它的DEMO代碼試試就知道了
不然重新寫一個JNI的庫,用android-serialport-api的也行,不然網上也好多現成的代碼,基本不用重寫

❸ android 串口編程是做什麼用的

有藍牙串口, 也有usb串口, 就是用來讀取數據的啊, 例如otg通信中, 就是通過usb串口來通信的, 藍牙的話就是通過無線來通信.

❹ 怎麼查看android 設備的串口

1. 如果是linux,不需要單獨安裝什麼串口驅動
2. 但需要使用ls /dev/tty * 查看usb 串口設備是否被檢測到
2. 然後使用linux下的MINICOM進行串口信息列印,具體配置和用法可以一下

❺ 誰有沒有Android串口的使用例子

1 首先做的是創建新的工程然後添加一下文件


3代碼

好了 然後就是關於這個頁面的Code了,

這是我的:

package android.serialport;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.BreakIterator;
import java.util.ServiceConfigurationError;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MyserialActivity extendsActivity
{
EditText sendedit;
EditText receiveedit;
FileInputStream mInStream;
FileOutputStream mOutStream;
SerialPort classserialport;
ReadThread mReadThread;

private class ReadThread extends Thread
{
public void run()
{
super.run();
while(!isInterrupted())
{
int size;
}
}
}


void onDataReceive(final byte[] buffer,finalint size)
{
runOnUiThread(new Runnable()
{

@Override
publicvoid run()
{
// TODO Auto-generated method stub
if(mReadThread != null)
{
receiveedit.append(newString(buffer,0,size));
}
}
});
}
@Override
protectedvoid onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_myserial);

sendedit= (EditText)findViewById(R.id.editText1);
receiveedit=(EditText)findViewById(R.id.editText2);


receiveedit.setFocusable(false);//進制輸入
/*
* 打開串口
* */
finalButton openserial =(Button)findViewById(R.id.button1);
openserial.setOnClickListener(newView.OnClickListener()
{

@Override
publicvoid onClick(View arg0)
{
//TODO Auto-generated method stub
try
{
classserialport=new SerialPort(new File("/dev/ttyS2"),9600);
}catch(SecurityExceptione)
{
e.printStackTrace();
}
catch(IOExceptione)
{
e.printStackTrace();
}
mInStream=(FileInputStream) classserialport.getInputStream();
Toast.makeText(MyserialActivity.this,"串口打開成功",Toast.LENGTH_SHORT).show();
}
});
/*
* 發送數據
* */
finalButton sendButton =(Button)findViewById(R.id.button2);
sendButton.setOnClickListener(newView.OnClickListener()
{

@Override
publicvoid onClick(View arg0)
{

Stringindata;
indata=sendedit.getText().toString();
//TODO Auto-generated method stub
try
{
mOutStream=(FileOutputStream) classserialport.getOutputStream();
mOutStream.write(indata.getBytes());
mOutStream.write(' ');
}
catch(IOExceptione)
{
e.printStackTrace();
}
Toast.makeText(MyserialActivity.this,"數據發送成功",Toast.LENGTH_SHORT).show();
sendedit.setText("");
}
});
/*
* 接收數據
* */
finalButton receButton= (Button)findViewById(R.id.button3);
receButton.setOnClickListener(newView.OnClickListener()
{//inttag =0;

@Override
publicvoid onClick(View arg0)
{
// TODO Auto-generated method stub
intsize;
try
{
byte[]buffer = new byte[64];
if(mInStream== null) return;
size= mInStream.read(buffer);
if(size>0)
{
receiveedit.setText("");

}
if(size>0)
{
onDataReceive(buffer,size);
}
inttag =1;

receiveedit.setText(newString(buffer, 0, size));

}catch(IOExceptione)
{
e.printStackTrace();
return;
}
}

privateboolean isInterrupted()
{
// TODO Auto-generated methodstub
returnfalse;
}
});
/*
* 清楚接收區
* */
finalButton ClearButton = (Button)findViewById(R.id.clear);
ClearButton.setOnClickListener(newView.OnClickListener()
{

@Override
publicvoid onClick(View arg0)
{
//TODO Auto-generated method stub
receiveedit.setText("");
}
});}

@Override
publicboolean onCreateOptionsMenu(Menu menu)
{
//Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.myserial,menu);
returntrue;
}

}

好吧 你做好了。

3需要載入的文件

下面我把所需要添加的代碼貼一貼

第一個是Serialport.java

/*
* Copyright 2009 Cedric Priscal
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package android.serialport;

import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.util.Log;

public class SerialPort {

private static final String TAG = "SerialPort";

/*
* Do not remove or rename the field mFd: it is used by native method close();
*/
private FileDescriptor mFd; //創建一個文件描述符對象 mFd
private FileInputStream mFileInputStream;
private FileOutputStream mFileOutputStream;

public SerialPort(File device, int baudrate) throws SecurityException, IOException {
/*
* 檢查訪問許可權
* */
/* Check access permission */
if (!device.canRead() || !device.canWrite()) {//如果設備不可讀或者設備不可寫
try {
/* Missing read/write permission, trying to chmod the file *///沒有讀寫許可權,就嘗試去掛載許可權
Process su; //流程進程 su
su = Runtime.getRuntime().exec("/system/bin/su");//通過執行掛載到/system/bin/su 獲得執行
String cmd = "chmod 777 " + device.getAbsolutePath() + " "
+ "exit ";
/*String cmd = "chmod 777 /dev/s3c_serial0" + " "
+ "exit ";*/
su.getOutputStream().write(cmd.getBytes());//進程。獲得輸出流。寫(命令。獲得二進制)
if ((su.waitFor() != 0) || !device.canRead()
|| !device.canWrite()) {//如果 進程等待不是0 或者 設備不能讀寫就
throw new SecurityException();//拋出一個許可權異常
}
} catch (Exception e) {
e.printStackTrace();
throw new SecurityException();
}
}
/*
*
* */
mFd = open(device.getAbsolutePath(), baudrate);
//device.getAbsolutePath()這是要掛載的路徑new File("/dev/ttyS2")
if (mFd == null) {
Log.e(TAG, "native open returns null");
throw new IOException();//輸入輸出異常
}
//將文件描述符 做輸入輸出流的參數 傳遞給創建的輸入輸出流
mFileInputStream = new FileInputStream(mFd);
mFileOutputStream = new FileOutputStream(mFd);
}

// Getters and setters
public InputStream getInputStream() {
return mFileInputStream;
}

public OutputStream getOutputStream() {
return mFileOutputStream;
}

// JNI
private native static FileDescriptor open(String path, int baudrate);
public native void close();
static {
System.loadLibrary("serial_port");
}
}

第二個是SerialPortFinder.java

/*
* Copyright 2009 Cedric Priscal
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package android.serialport;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.LineNumberReader;
import java.util.Iterator;
import java.util.Vector;

import android.util.Log;

public class SerialPortFinder {

/*
* 創建一個驅動程序類
* */
public class Driver {
public Driver(String name, String root) {
mDriverName = name;//String 類型的
mDeviceRoot = root;
}
private String mDriverName;
private String mDeviceRoot;
Vector<File> mDevices = null;
/*
* Vector 類在 java 中可以實現自動增長的對象數組
* 簡單的使用方法如下:
vector<int> test;//建立一個vector
test.push_back(1);
test.push_back(2);//把1和2壓入vector這樣test[0]就是1,test[1]就是2
* */
public Vector<File> getDevices() {
if (mDevices == null) {
mDevices = new Vector<File>();
File dev = new File("/dev");
File[] files = dev.listFiles();
int i;
for (i=0; i<files.length; i++) {
if (files[i].getAbsolutePath().startsWith(mDeviceRoot)) {
Log.d(TAG, "Found new device: " + files[i]);
mDevices.add(files[i]);
}
}
}
return mDevices;
}

public String getName() {
return mDriverName;
}
}
/*
*
*
* */
private static final String TAG = "SerialPort";

private Vector<Driver> mDrivers = null;

Vector<Driver> getDrivers() throws IOException {
if (mDrivers == null) {
mDrivers = new Vector<Driver>();
LineNumberReader r = new LineNumberReader(new FileReader("/proc/tty/drivers"));
String l;
while((l = r.readLine()) != null) {
String[] w = l.split(" +");
if ((w.length == 5) && (w[4].equals("serial"))) {
Log.d(TAG, "Found new driver: " + w[1]);
mDrivers.add(new Driver(w[0], w[1]));
}
}
r.close();
}
return mDrivers;
}

public String[] getAllDevices() {
Vector<String> devices = new Vector<String>();
// Parse each driver
Iterator<Driver> itdriv;
try {
itdriv = getDrivers().iterator();
while(itdriv.hasNext()) {
Driver driver = itdriv.next();
Iterator<File> itdev = driver.getDevices().iterator();
while(itdev.hasNext()) {
String device = itdev.next().getName();
String value = String.format("%s (%s)", device, driver.getName());
devices.add(value);
}
}
} catch (IOException e) {
e.printStackTrace();
}
return devices.toArray(new String[devices.size()]);
}

public String[] getAllDevicesPath() {
Vector<String> devices = new Vector<String>();
// Parse each driver
Iterator<Driver> itdriv;
try {
itdriv = getDrivers().iterator();
while(itdriv.hasNext()) {
Driver driver = itdriv.next();
Iterator<File> itdev = driver.getDevices().iterator();
while(itdev.hasNext()) {
String device = itdev.next().getAbsolutePath();
devices.add(device);
}
}
} catch (IOException e) {
e.printStackTrace();
}
return devices.toArray(new String[devices.size()]);
}
}

第三個是Android.mk

#
# Copyright 2009 Cedric Priscal
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

TARGET_PLATFORM := android-3
LOCAL_MODULE := serial_port
LOCAL_SRC_FILES := SerialPort.c
LOCAL_LDLIBS := -llog

include $(BUILD_SHARED_LIBRARY)

第四個是SerialPort.c

/*
* Copyright 2009 Cedric Priscal
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <jni.h>

#include "android/log.h"
static const char *TAG="serial_port";
#define LOGI(fmt, args...) __android_log_print(ANDROID_LOG_INFO, TAG, fmt, ##args)
#define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_DEBUG, TAG, fmt, ##args)
#define LOGE(fmt, args...) __android_log_print(ANDROID_LOG_ERROR, TAG, fmt, ##args)

static speed_t getBaudrate(jint baudrate)
{
switch(baudrate) {
case 0: return B0;
case 50: return B50;
case 75: return B75;
case 110: return B110;
case 134: return B134;
case 150: return B150;
case 200: return B200;
case 300: return B300;
case 600: return B600;
case 1200: return B1200;
case 1800: return B1800;
case 2400: return B2400;
case 4800: return B4800;
case 9600: return B9600;
case 19200: return B19200;
case 38400: return B38400;
case 57600: return B57600;
case 115200: return B115200;
case 230400: return B230400;
case 460800: return B460800;
case 500000: return B500000;
case 576000: return B576000;
case 921600: return B921600;
case 1000000: return B1000000;
case 1152000: return B1152000;
case 1500000: return B1500000;
case 2000000: return B2000000;
case 2500000: return B2500000;
case 3000000: return B3000000;
case 3500000: return B3500000;
case 4000000: return B4000000;
default: return -1;
}
}

/*
* Class: cedric_serial_SerialPort
* Method: open
* Signature: (Ljava/lang/String;)V
*/
JNIEXPORT jobject JNICALL Java_android_serialport_SerialPort_open
(JNIEnv *env, jobject thiz, jstring path, jint baudrate)
{
int fd;
speed_t speed;
jobject mFileDescriptor;

/* Check arguments */
{
speed = getBaudrate(baudrate);
if (speed == -1) {
/* TODO: throw an exception */
LOGE("Invalid baudrate");
return NULL;
}
}

/* Opening device */
{
jboolean is;
const char *path_utf = (*env)->GetStringUTFChars(env, path, &is);
LOGD("Opening serial port %s", path_utf);
fd = open(path_utf, O_RDWR | O_DIRECT | O_SYNC);
LOGD("open() fd = %d", fd);
(*env)->ReleaseStringUTFChars(env, path, path_utf);
if (fd == -1)
{
/* Throw an exception */
LOGE("Cannot open port");
/* TODO: throw an exception */
return NULL;
}
}

/* Configure device */
{
struct termios cfg;
LOGD("Configuring serial port");
if (tcgetattr(fd, &cfg))
{
LOGE("tcgetattr() failed");
close(fd);
/* TODO: throw an exception */
return NULL;
}

cfmakeraw(&cfg);
cfsetispeed(&cfg, speed);
cfsetospeed(&cfg, speed);

if (tcsetattr(fd, TCSANOW, &cfg))
{
LOGE("tcsetattr() failed");
close(fd);
/* TODO: throw an exception */
return NULL;
}
}

/* Create a corresponding file descriptor */
{
jclass cFileDescriptor = (*env)->FindClass(env, "java/io/FileDescriptor");
jmethodID iFileDescriptor = (*env)->GetMethodID(env, cFileDescriptor, "<init>", "()V");
jfieldID descriptorID = (*env)->GetFieldID(env, cFileDescriptor, "descriptor", "I");
mFileDescriptor = (*env)->NewObject(env, cFileDescriptor, iFileDescriptor);
(*env)->SetIntField(env, mFileDescriptor, descriptorID, (jint)fd);
}

return mFileDescriptor;
}

/*
* Class: cedric_serial_SerialPort
* Method: close
* Signature: ()V
*/
JNIEXPORT void JNICALL Java_android_serialport_SerialPort_close
(JNIEnv *env, jobject thiz)
{
jclass SerialPortClass = (*env)->GetObjectClass(env, thiz);
jclass FileDescriptorClass = (*env)->FindClass(env, "java/io/FileDescriptor");

jfieldID mFdID = (*env)->GetFieldID(env, SerialPortClass, "mFd", "Ljava/io/FileDescriptor;");
jfieldID descriptorID = (*env)->GetFieldID(env, FileDescriptorClass, "descriptor", "I");

jobject mFd = (*env)->GetObjectField(env, thiz, mFdID);
jint descriptor = (*env)->GetIntField(env, mFd, descriptorID);

LOGD("close(fd = %d)", descriptor);
close(descriptor);
}

❻ Android串口通訊

1.打開串口。

2.串口處於監聽狀態

3.想串口寫入數胡鋒據,串口接收到數據返回數據

SerialPort類所嫌遲在的包一定要和上圖包名一直,因為串口通訊需要使用jni中褲者晌的函數。

package android_serialport_api;

import java.io.File;

import java.io.FileDescriptor;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import com.fx.serialporttest.L;

public class SerialPort {

/*

* Do not remove or rename the field mFd: it is used by native method

* close();

*/

private FileDescriptor mFd;

private FileInputStream mFileInputStream;

private FileOutputStream mFileOutputStream;

/**

* 構造方法

* @param device 串口地址

* @param baurate 波特率

* @param flags

* @throws IOException

* @throws InterruptedException

*/

public SerialPort(File device,int baudrate,int flags) {

/*

* 檢測是否有訪問許可權

*/

if(!device.canRead()||!device.canWrite()){

//如果沒有讀寫許可權,嘗試chmod命令這個文件

L.tag("沒有讀寫許可權");

Process su;

try {

su = Runtime.getRuntime().exec("/system/bin/su");//獲取root讀寫許可權

String cmd = "chmod 777"+device.getAbsolutePath()+"\n"+"exit\n";

su.getOutputStream().write(cmd.getBytes()); //向此路徑文件寫入命令

if((su.waitFor()!=0||!device.canRead()||!device.canWrite())){

throw new SecurityException();

}

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

mFd = open(device.getAbsolutePath(),baudrate,flags);

if(mFd==null){

mFd = open(device.getAbsolutePath(),baudrate,flags);

L.tag("native open return null");

}

mFileInputStream = new FileInputStream(mFd);

mFileOutputStream = new FileOutputStream(mFd);

}

public FileInputStream getmFileInputStream() {

return mFileInputStream;

}

public void setmFileInputStream(FileInputStream mFileInputStream) {

this.mFileInputStream = mFileInputStream;

}

public FileOutputStream getmFileOutputStream() {

return mFileOutputStream;

}

public void setmFileOutputStream(FileOutputStream mFileOutputStream) {

this.mFileOutputStream = mFileOutputStream;

}

//JNI

private native static FileDescriptor open(String path,int baudrate,int flags);

public native void close();

static {

System.loadLibrary("serial_port");

}

}

package android_serialport_api;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import com.fx.serialporttest.L;

public  class SerialPortFinger {

private static ReadThread readThread;

private static FileInputStream mFileInputStream;

private static FileOutputStream mFileOutputStream;

static String path = "/dev/ttyS0";//設備主板的串口地址,地址有所不同

public  void startListener(){

SerialPort serialPort = new SerialPort(new File(path), 9600, 0);//9600是波特率,這個也是有所不同,具體要看設備

mFileInputStream = serialPort.getmFileInputStream();

mFileOutputStream = serialPort.getmFileOutputStream();//獲取串口寫入流

readThread  = new ReadThread();

readThread.start();//開啟監聽

}

/**

* 發送指令到串口

*

* @param cmd

* @return

*/

public boolean sendCmds(String cmd) {

boolean result = true;

byte[] mBuffer = (cmd+"\r\n").getBytes();

try {

if (mFileOutputStream != null) {

mFileOutputStream.write(mBuffer);

} else {

result = false;

}

} catch (IOException e) {

e.printStackTrace();

result = false;

}

return result;

}

static class ReadThread extends Thread{

@Override

public void run() {

// TODO Auto-generated method stub

super.run();

int len;

StringBuffer sb = new StringBuffer("");

while(true){ //循環監聽串口,讀取返回的數據

byte[] buffer = new byte[1024];

if(mFileInputStream==null){

return;

}

try {

len = mFileInputStream.read(buffer);

if(len>0){

sb.append(new String(buffer, 0, len));

}

if(!sb.toString().equals(""))

{

L.tag(sb.toString());//收到串口的返回數據,在日誌中列印出來

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

L.tag("接受完成");

}

}

}

}

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