Step by step to teach you the simple completion of Android USB development

There is a new requirement in the project that a USB thermometer can be connected, the app can read the body temperature data from the thermometer, and a search has found a great USB communication library.
GitHub Address: Usb-serial-for-android

Preparatory work

1. Clone This library's source file from GitHub

2. Introducing modules in Android Studio
   

3. adding dependencies in Build.gradlecompile project(path: ‘:usbSerialForAndroid‘)

4. Copy Device_filter.xml to the project's res/xml/folder
   

5. Configuring the Androidmanifest.xml File

<uses-feature android:name="android.hardware.usb.host" /><application>    <activity        android:name="..."        ...>      <intent-filter>        <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />      </intent-filter>      <meta-data          android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" android:resource="@xml/device_filter" /> </activity></application>

Use

Sample code parsing:

Get system service Get Usbmanager instance Usbmanager Manager = (Usbmanager) getsystemservice (Context.usb_service);Find all plugged-in devices list<usbserialdriver> availabledrivers = Usbserialprober.getdefaultprober (). FindAllDrivers ( Manager);if (Availabledrivers.isempty ()) {return;}Open the device and establish a communication connection usbserialdriver driver = availabledrivers.Get0); Usbdeviceconnection connection = Manager.opendevice (Driver.getdevice ());if (connection = =NULL) {You probably need-to-call Usbmanager.requestpermission (Driver.getdevice (),..)return;}//open port, set port parameters, read data usbserialport port = Driver.getports (). get (0); 115200, 8, Usbserialport.stopbits_1, Usbserialport.parity_none); byte buffer[] = new byte[16]; int numbytesread = port.read (buffer, 1000); LOG.D (TAG,  "Read" + numbytesread +  "bytes.");} catch (IOException e) {//Deal with error.} finally {port.close ();}            

The code above is a sample code written by the library author, which shows that it is very simple to use, and the following code demonstrates how to encapsulate a USB operation in a class.

PublicClassTemperatureusbcontrol {PrivateStaticFinal String TAG = TemperatureUsbControl.class.getSimpleName ();PrivateStaticFinal String temperature_usb_vendor_id ="067B";Vendor IDPrivateStaticFinal String temperature_usb_product_id ="2303";Product IDPrivate Context Mcontext;Private Usbmanager Musbmanager;USB ManagerPrivate Usbserialport Stemperatureusbport =NullUSB port for temperature gunPrivate Serialinputoutputmanager Mserialiomanager;Input and output manager (essentially a runnable)PrivateFinal Executorservice mexecutor = Executors.newsinglethreadexecutor ();Used to continuously read data from the portData input/Output listenerPrivateFinal Serialinputoutputmanager.listener Mlistener =New Serialinputoutputmanager.listener () {@OverridePublicvoidOnrunerror (Exception e) {log.d (TAG,"Runner stopped."); }@OverridePublicvoidOnnewdata (FinalByte[] data) {LOG.D (TAG,"New data."); } };PublicTemperatureusbcontrol (Context context) {Mcontext = context;}PublicvoidInitusbcontrol () {Musbmanager = (Usbmanager) mcontext.getsystemservice (Context.usb_service);All devices list<usbserialdriver> usbserialdrivers = Usbserialprober.getdefaultprober (). FindAllDrivers ( Musbmanager);All ports list<usbserialport> Usbserialports =New Arraylist<usbserialport> ();for (Usbserialdriver driver:usbserialdrivers) {list<usbserialport> ports = Driver.getports (); LOG.D (TAG, String.Format ("+%s:%s port%s", Driver, Integer.valueof (Ports.size ()), ports.size () = =1?"" :"S")); Usbserialports.addall (ports); } String VendorID; String productId;Calibration equipment, equipment is 2303 equipmentfor (Usbserialport port:usbserialports) {usbserialdriver driver = Port.getdriver (); Usbdevice device = Driver.getdevice (); VendorID = Hexdump.tohexstring ((Short) Device.getvendorid ()); ProductId = Hexdump.tohexstring ((Short) Device.getproductid ());if (Vendorid.equals (temperature_usb_vendor_id) && productid.equals (temperature_usb_product_id)) { Stemperatureusbport = port; } }if (stemperatureusbport! =NULL) {Successfully get port, open connection Usbdeviceconnection connection = Musbmanager.opendevice (Stemperatureusbport.getdriver (). GetDevice ()) ;if (connection = =NULL) {LOG.E (TAG,"Opening device Failed");Return }try {stemperatureusbport.open (connection);Set the baud rate stemperatureusbport.setparameters (4800,8, Usbserialport.stopbits_1, Usbserialport.parity_none); }catch (IOException e) {Open port failed, shut down! LOG.E (TAG,"Error Setting up Device:" + e.getmessage (), E);try {stemperatureusbport.close ();}catch (IOException E2) {Ignore. } Stemperatureusbport =NullReturn } }else {Prompt not detected device}}PublicvoidOndevicestatechange () {Re-open the USB manager Stopiomanager (); Startiomanager (); }PrivatevoidStartiomanager () {if (stemperatureusbport! =NULL) {LOG.I (TAG,"Starting IO Manager.."); Mserialiomanager =New Serialinputoutputmanager (Stemperatureusbport, Mlistener); Mexecutor.submit (Mserialiomanager);//essence is to read the USB port continuously with a thread}} private void Stopiomanager () { if (mserialiomanager! = null) {LOG.I (TAG, "stopping IO Manager: "); Mserialiomanager.stop (); Mserialiomanager = null;}} public void OnPause () {Stopiomanager (); if (stemperatureusbport! = null) { try {stemperatureusbport.close ();} catch (IOException e) { //Ignore.} stemperatureusbport = null;      }}} 

Use in activity:

    @OverrideProtectedvoidOnCreate (Bundle savedinstancestate) {Super.oncreate (savedinstancestate); Setcontentview (R.layout.activity_punch); Initusbcontrol ();Initialize the USB controller}/** * Initialize USB */PrivatevoidInitusbcontrol () {Mtemperatureusbcontrol =New Temperatureusbcontrol (Mcontext); Mtemperatureusbcontrol.initusbcontrol (); }@OverrideProtectedvoidOnresume () {Super.onresume (); Intentfilter Usbfilter =New Intentfilter (); Usbfilter.addaction (usbmanager.action_usb_device_attached); Usbfilter.addaction (usbmanager.action_usb_device_detached); Registerreceiver (Musbreceiver, Usbfilter); Mtemperatureusbcontrol.ondevicestatechange (); }@OverrideProtectedvoidOnPause () {Super.onpause (); Mtemperatureusbcontrol.onpause (); Unregisterreceiver (Musbreceiver); }/** * Broadcasreceiver to detect the USB insertion status */private final broadcastreceiver mUsbReceiver = new broadcastreceiver () {public void onreceive (context context, Intent Intent) {String action = intent.getaction (); if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals (ACTION)) {//device insertion Mtemperatureusbcontrol.initusbcontrol (); Mtemperatureusbcontrol.ondevicestatechange (); LOG.E (TAG,  "action_usb_device_attached");} else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals ( Action) {//device removal mtemperatureusbcontrol.onpause (); LOG.E (TAG,  "action_usb_device_detached");}} };

Read the data if you need to use it in the activity, you can use Eventbus to complete the ~

Step by step to teach you the simple completion of Android USB development