Android USB转串口通信
一、引用
二、截图
废话不多说，先上图，micro usb -> usb 连接的测试温度的外设（其实是个测试粮油品质的，还有TPM值等等）
usb_connect.png
三、流程
1、mainfest中注册监听USB拔插动作并且过滤对应vid,pid的设备。这个是静态的，在下面实例中用的是动态的，具体可以参考引用中的第【2】个。
2、查找所有的USB设备
3、动态注册需要用的USB设备权限
4、连接已注册的USB设备，并设置连接参数
5、设置返回监听，并对话
6、按照不同的协议解析byte[]数据获得对应数据（在此不表）
7、关闭连接等
四、代码
0、配置：git上的案例，把其中usbSerialForAndroid的这个module拿下来，关联到自己的工程上面去
build.gradle-app
dependencies {
compile project(':usbSerialForAndroid')
}
settings.gradle
include ':app', 'usbSerialForAndroid'
1、动态监听USB拔插动作+USB注册动作
private String USB_PERMISSION = "xxxxxxxxxx.usb.permission";
private PendingIntent mPrtPermissionIntent; //获取外设权限的意图
/**
* 动态注册usb广播，拔插动作，注册动作
* */
private void register(){
//注册在此service下的receiver的监听的action
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
intentFilter.addAction(UsbManager.ACTION_USB_ACCESSORY_ATTACHED);
intentFilter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
intentFilter.addAction(USB_PERMISSION);
registerReceiver(usbReceiver, intentFilter);//注册receiver
//通知监听外设权限注册状态
//PendingIntent：连接外设的intent
//ask permission
mPrtPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(USB_PERMISSION), 0);
}
private BroadcastReceiver usbReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
if (intent == null) {
return;
}
String action = intent.getAction();
// USB注册动作
if (USB_PERMISSION.equals(action)) {
synchronized (this) {
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if ((UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE) != null) {
// usbDev = (UsbDevice)
// intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
// after request dev permission and granted
// pemission , connect printer by usb
LogUtil.i("after request dev permission and granted pemission , connect printer by usb.");
getUsbInfo(mUsbSerialPort.getDriver().getDevice());
} else {
LogUtil.e("usb device suddenly disappera.");
ToastUtil.showShort(instance,"USB外设意外消失。");
}
} else {
LogUtil.e("usb permission granted fail.");
ToastUtil.showShort(instance, "USB权限注册失败。");
}
}
}
// USB拔插动作
else if(UsbManager.ACTION_USB_ACCESSORY_ATTACHED.equals(action)
|| UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)){
LogUtil.i("USB 插入...");
search();
}
}
};
2、查询所有USB设备
//查询设备
private void search(){
usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
List<UsbSerialDriver> drivers =
UsbSerialProber.getDefaultProber().findAllDrivers(usbManager);
//try get enable printer dev
if (drivers.size() > 0) {
usbDevicesList.clear();
for(UsbSerialDriver driver : drivers){
usbDevicesList.addAll(driver.getPorts());
}
adapter.notifyDataSetChanged();
}else{
LogUtil.e("not find device.");
return;
}
}
3、动态注册需要用的USB设备权限（会走到1中的receiver中）
@Override
public void onItemClick(View view, int position) {
mUsbSerialPort = usbDevicesList.get(position);
RequestNormalPermission(usbManager, mUsbSerialPort.getDriver().getDevice());
}
/**
* 请求权限：一般来说有弹框
*/
public void RequestNormalPermission(UsbManager usbManager,UsbDevice device) {
if (!usbManager.hasPermission(device)) {
// ask has dev permission,pop dialog
LogUtil.d("printer dev has no permission,try request it.");
ToastUtil.showShort(this,"printer dev has no permission,try request it.");
usbManager.requestPermission(device, mPrtPermissionIntent);// will recall mReceiver
} else {
// when dev has granted permission , connect printer by usb
LogUtil.d("printer dev has granted permission,connect usb.");
ToastUtil.showShort(this, "USB权限注册成功。");
getUsbInfo(mUsbSerialPort.getDriver().getDevice());
}
}
4、连接已注册的USB设备，并设置连接参数 + 5、设置返回监听，并对话 + 7、关闭连接等
/**
* 获得授权USB的基本信息
* 1、USB接口，一般是第一个
* 2、USB设备的输入输出端
*
* */
private void getUsbInfo(UsbDevice usbDevice){
StringBuilder sb = new StringBuilder();
if(Build.VERSION.SDK_INT >= 23){
sb.append(String.format("VID:%04X PID:%04X ManuFN:%s PN:%s V:%s",
usbDevice.getVendorId(),
usbDevice.getProductId(),
usbDevice.getManufacturerName(),
usbDevice.getProductName(),
usbDevice.getVersion()
));
}
else if(Build.VERSION.SDK_INT >= 21){
sb.append(String.format("VID:%04X PID:%04X ManuFN:%s PN:%s",
usbDevice.getVendorId(),
usbDevice.getProductId(),
usbDevice.getManufacturerName(),
usbDevice.getProductName()
));
}
else{
sb.append(String.format("VID:%04X PID:%04X",
usbDevice.getVendorId(),
usbDevice.getProductId()
));
}
tv_usb.setText(sb.toString());
connect();//连接
}
/**
* usb设备的连接
* */
private void connect(){
LogUtil.i("usb connect...");
usbDeviceConnection = null;
usbDeviceConnection = usbManager.openDevice(mUsbSerialPort.getDriver().getDevice());
if(usbDeviceConnection == null){
ll_usb_connect.setVisibility(View.GONE);
tv_usb.setText(tv_usb.getText().toString() + " 连接失败！！！");
}else{
tv_usb.setText(tv_usb.getText().toString() + " 连接成功。");
ll_usb_connect.setVisibility(View.VISIBLE);
tv_connect_state.setText("USB通信");
tv_receive.setText("");
et_send.setText("01 03 00 01 00 01 D5 CA");
setConnectionParam();
onDeviceStateChange();
}
}
/**
* 设置通讯参数
* */
private void setConnectionParam(){
try {
if(mUsbSerialPort.getDriver().getDevice().getInterfaceCount() > 0){
mUsbSerialPort.open(usbDeviceConnection);
mUsbSerialPort.setParameters(115200, 8, UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE);
StringBuilder sb = new StringBuilder();
sb.append( "\n CD - Carrier Detect = "+mUsbSerialPort.getCD());
sb.append( "\n CTS - Clear To Send = "+mUsbSerialPort.getCTS());
sb.append( "\n DSR - Data Set Ready = "+mUsbSerialPort.getDSR());
sb.append( "\n DTR - Data Terminal Ready = "+mUsbSerialPort.getDTR());
sb.append( "\n DSR - Data Set Ready = "+mUsbSerialPort.getDSR());
sb.append( "\n RI - Ring Indicator = "+mUsbSerialPort.getRI());
sb.append( "\n RTS - Request To Send = "+mUsbSerialPort.getRTS());
tv_connect_state.setText(sb.toString());
try {
mUsbSerialPort.setDTR(true);
}catch (IOException x){
LogUtil.e("IOException DTR: " + x.getMessage());
}
try {
mUsbSerialPort.setRTS(true);
}catch (IOException x){
LogUtil.e("IOException RTS: " + x.getMessage());
}
}
//无通讯接口
else{
tv_connect_state.setText("该USB无通讯接口");
}
} catch (IOException e) {
LogUtil.e("Error setting up device: " + e.getMessage());
tv_connect_state.setText("Error opening device: " + e.getMessage());
try {
mUsbSerialPort.close();
} catch (IOException e2) {
// Ignore.
}
mUsbSerialPort = null;
return;
}
}
public boolean sendData(byte[] data) {
LogUtil.i("sendData:"+Arrays.toString(data));
if (mSerialIoManager != null) {
mSerialIoManager.writeAsync(data);
}
return false;
}
private final SerialInputOutputManager.Listener mListener =
new SerialInputOutputManager.Listener() {
@Override
public void onRunError(Exception e) {
LogUtil.d("Runner stopped.");
}
@Override
public void onNewData(final byte[] data) {
LogUtil.i("onReceiver data="+Arrays.toString(data));
instance.runOnUiThread(new Runnable() {
@Override
public void run() {
tv_receive.setText(HexUtil.bytesToHexString(data));
}
});
}
};
/**
* usb设备断开连接
* */
private void disconnect(){
LogUtil.e("usb disconnect...");
stopIoManager();
if (mUsbSerialPort != null) {
try {
mUsbSerialPort.close();
} catch (IOException e) {
// Ignore.
}
mUsbSerialPort = null;
}
//usbdevice usbmanager
}
private void stopIoManager() {
if (mSerialIoManager != null) {
LogUtil.i("Stopping io manager ..");
mSerialIoManager.stop();
mSerialIoManager = null;
}
}
private void startIoManager() {
if (mSerialIoManager == null) {
LogUtil.i("Starting io manager ..");
mSerialIoManager = new SerialInputOutputManager(mUsbSerialPort, mListener);
mExecutor.submit(mSerialIoManager);
}
}
private void onDeviceStateChange() {
stopIoManager();
startIoManager();
}
@Override
public void onDestroy() {
unregisterReceiver(usbReceiver);
usbReceiver = null;
disconnect();
super.onDestroy();
}
五、其他
参数意义
1 载波检测 DCD（Data Carrier Detect）
2 接收数据 RXD（Received Data）
3 发送数据 TXD（Transmit Data）
4 数据终端准备好 DTR（Data Terminal Ready）
5 信号地 SG（Signal Ground）
6 数据准备好 DSR（Data Set Ready）
7 请求发送 RTS（Request To Send）
8 清除发送 CTS（Clear To Send）
9 振铃提示 RI（Ring Indicator）
支持USB芯片种类
1、CDC ACM
2、CH34X
3、CP21XX
4、FTDI
5、Common USB
波特率参数等
这里是写死的，具体得看设备
