after the connection is established I want to read the value from the characteristic and save the value in a byte array.
Here is my function for the reading inside my BluetoothLeService:
public byte[] readWhiteAndIntensityCharacteristic() {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return null;
}
/*check if the service is available on the device*/
BluetoothGattService mCustomService = mBluetoothGatt.getService(UUID.fromString(UuidAdresssService));
if (mCustomService == null) {
Log.w(TAG, "Custom BLE Service not found");
return null;
}
/*get the read characteristic from the service*/
BluetoothGattCharacteristic mReadCharacteristic = mCustomService.getCharacteristic(UUID.fromString(UuidAdresssWhiteAndIntensityCharastic));
byte[] messageByte = mReadCharacteristic.getValue();
if (messageByte != null && messageByte.length > 0) {
final StringBuilder stringBuilder = new StringBuilder(messageByte.length);
for (byte byteChar : messageByte)
stringBuilder.append(String.format("%02X", byteChar));
s = "0x" + stringBuilder.toString();
Log.v("Scan Activity", s);
if (mBluetoothGatt.readCharacteristic(mReadCharacteristic) == false) {
Log.w(TAG, "Failed to read characteristic");
}
}
return messageByte;
}
This function get called inside my DeviceControlActivity:
public void getStartUpValue(){
Log.w(TAG, "Reading completed");}
if(mBluetoothLeService.readWhiteAndIntensityCharacteristic() == null)
{
Log.w(TAG, "FAILED Reading value failed");
}
startValue = mBluetoothLeService.readWhiteAndIntensityCharacteristic();
Log.w(TAG, "Reading completed");
}
I call the getStartUpValue function after the connection is established.
private final BroadcastReceiver mGattUpdateReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if (BluetoothLeService.ACTION_GATT_CONNECTED.equals(action)) {
mConnected = true;
updateConnectionState(R.string.connected);
invalidateOptionsMenu();
} else if (BluetoothLeService.ACTION_GATT_DISCONNECTED.equals(action)) {
mConnected = false;
updateConnectionState(R.string.disconnected);
invalidateOptionsMenu();
clearUI();
} else if (BluetoothLeService.ACTION_GATT_SERVICES_DISCOVERED.equals(action)) {
// Show all the supported services and characteristics on the user interface.
mBluetoothLeService.getSupportedGattServices();
getStartUpValue();
} else if (BluetoothLeService.ACTION_DATA_AVAILABLE.equals(action)) {
displayData(intent.getStringExtra(BluetoothLeService.EXTRA_DATA));
}
}
};
The reading is failing everytime but sending values to the characteristic is no problem.
How can I fix this problem?
The solution is: mBluetoothGatt.readCharacteristic(mReadCharacteristic)
After the reading is finished a callback will be called.
Thanks to Andrew Vovk
Related
After subscribe notification immediate write command doesn't work. I have to restart server device and auto connect to existing ble instance to get result.
Notification enable code:
public boolean setCharacteristicNotification(BluetoothGattCharacteristic characteristic,
boolean enabled) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return false;
}
mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
System.out.println("descriptor length----" + characteristic.getDescriptors().size());
// This is specific to Heart Rate Measurement.
if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
BluetoothGattDescriptor descriptor = characteristic.getDescriptor(
UUID.fromString("00002902-0000-1000-8000-00805f9b34fb"));
System.out.println("descriptor--" + Arrays.toString(descriptor.getValue()));
System.out.println("characteristic value--" + Arrays.toString(descriptor.getCharacteristic().getValue()));
descriptor.setValue(BluetoothGattDescriptor.ENABLE_INDICATION_VALUE);
return mBluetoothGatt.writeDescriptor(descriptor);
}
return false;
}
and here is my write command code:
public void writeCustomCharacteristic(String value) {
this.value = "";
this.command = value;
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
/*check if the service is available on the device*/
BluetoothGattService mCustomService = mBluetoothGatt.getService(UUID.fromString("65333333-a115-11e2-9e9a-0800200ca100"));
if (mCustomService == null) {
Log.w(TAG, "Custom BLE Service not found");
return;
}
/*get the read characteristic from the service*/
BluetoothGattCharacteristic mWriteCharacteristic = mCustomService.getCharacteristic(UUID.fromString("65333333-a115-11e2-9e9a-0800200ca101"));
mWriteCharacteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT);
mWriteCharacteristic.setValue(value.getBytes());
if (!mBluetoothGatt.writeCharacteristic(mWriteCharacteristic)) {
Log.w(TAG, "Failed to write characteristic");
}
System.out.println("BluetoothLeService.writeCustomCharacteristic------->" + value);
}
Before write any characteristic , delay for few sec . Bcz it takes time to execute.
new Handler(Looper.getMainLooper()).postDelayed(new Runnable() {
#Override
public void run() {
mBluetoothGatt.writeDescriptor(RTS_CCCD); //for descriptor
// or
mBluetoothGatt.readCharacteristic(brspInfo); //for read
//or
mBluetoothGatt.writeCharacteristic(brspInfo); //for write
}
}, 500);
Here you get more explaination
in the following coding i am getting battery level of some percentage.but i want to call notify characteristics so that for every 5 to 10 secs it updates the percentage of battery.so please help me.the following is my device control activity,in this i coded as follows.
private final BroadcastReceiver mGattUpdateReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if (BluetoothLeService.ACTION_DATA_AVAILABLE.equals(action)) {
displayData(intent.getStringExtra(BluetoothLeService.EXTRA_DATA));
}
}
};
and in the following method i am setting battery value and displaying in the value in percentage on image.
private void displayData(String data) {
Log.v("______________________No serives_______________",data );
if (data != null) {
mBluetoothLeService.setCharacteristicNotification(mNotifyCharacteristic, true);
battery.setText(data);
int x=Integer.parseInt(battery.getText().toString());
image_level.getLayoutParams().height = x*2;
}
else if (data==null)
battery.setText(data);
}
and the following is my ble service in this i add the set notification method wh
ich is as follows.
public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic,
boolean enabled) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
//For cube write
if (UUID_BatteryService.equals(characteristic.getUuid())) {
BluetoothGattDescriptor descriptor = characteristic.getDescriptor(
UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
mBluetoothGatt.writeDescriptor(descriptor);
}
}
public void onCharacteristicChanged(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
}
};
public boolean writeCharacteristic(BluetoothGattCharacteristic i){
//check mBluetoothGatt is available
if (mBluetoothGatt == null) {
Log.e(TAG, "lost connection");
return false;
}
BluetoothGattService Service = mBluetoothGatt.getService(UUID_BatteryService);
if (Service == null) {
Log.e(TAG, "service not found!");
//////////NO service found...........
return false;
}
boolean status = mBluetoothGatt.writeCharacteristic(i);
Log.e(TAG, "bluetooth write status"+status);
return status;
}
private void broadcastUpdate(final String action) {
final Intent intent = new Intent(action);
sendBroadcast(intent);
}
private void broadcastUpdate(final String action,
final BluetoothGattCharacteristic characteristic) {
final Intent intent = new Intent(action);
if(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG_BATTERY.
toString().
equalsIgnoreCase(characteristic.getUuid().toString())) {
Log.v("_____________","in broadcastupdate..........");
final byte[] data = characteristic.getValue();
if (data != null && data.length > 0) {
final StringBuilder stringBuilder = new StringBuilder(data.length);
for(byte byteChar : data)
stringBuilder.append(String.format("%02X ", byteChar));
final int flag = characteristic.getProperties();
int format = -1;
if ((flag & 0x01) != 0) {
format = BluetoothGattCharacteristic.FORMAT_UINT16;
Log.d(TAG, " format UINT16.");
} else {
format = BluetoothGattCharacteristic.FORMAT_UINT8;
Log.d(TAG, " UINT8.");
}
int batterylevel = characteristic.getIntValue(format, 0);
intent.putExtra(EXTRA_DATA, String.valueOf(batterylevel));
//intent.putExtra(EXTRA_DATA,new String(data));
}
}
sendBroadcast(intent);
}
If I well understood your question, you will need a Timer in order to check you battery level regularly.
For instance, you could use this code after starting your device control activity, maybe at the end of the onServiceConnected method :
please put the timer at the end of onServiceConnected() method of mServiceConnection object
Timer timer = new Timer("batteryTimer");
TimerTask task = new TimerTask() {
#Override
public void run() {
mBluetoothLeService.getBattery();
}
};
timer.scheduleAtFixedRate(task, 0, 5000);
And do not forget to call timer.cancel() when the activity is finishing.
And in the service, you could put something like that :
public void getBattery() {
if (mBluetoothGatt == null) {
Log.e(TAG, "lost connection");
}
BluetoothGattService batteryService = mBluetoothGatt.getService(Battery_Service_UUID);
if(batteryService == null) {
Log.d(TAG, "Battery service not found!");
return;
}
BluetoothGattCharacteristic batteryLevel = batteryService.getCharacteristic(Battery_Level_UUID);
if(batteryLevel == null) {
Log.d(TAG, "Battery level not found!");
return;
}
mBluetoothGatt.readCharacteristic(batteryLevel);
}
It is an example which would need to be modified but that gives you an idea on how to do it.
Somebody already did access to the battery value in the link below :
How to get the battery level after connect to the BLE device?
I am working on a BLE project (Android application) using Android 4.3 API, i have used sample BLE app it is only reading characteristics in DeviceControlActivity.activity, but i want to write characteristics and send it to BLE chip on clicking a button. How can I write data on chip cc2540 .. Basically i don't know the step by step procedure to write characteristics.
write i can only see the name and id of device with following piece of code in DeviceControlActivity
private final ExpandableListView.OnChildClickListener servicesListClickListner =
new ExpandableListView.OnChildClickListener() {
#Override
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition,
int childPosition, long id) {
if (mGattCharacteristics != null) {
final BluetoothGattCharacteristic characteristic =
mGattCharacteristics.get(groupPosition).get(childPosition);
final int charaProp = characteristic.getProperties();
if ((charaProp | BluetoothGattCharacteristic.PROPERTY_READ) > 0) {
// If there is an active notification on a characteristic, clear
// it first so it doesn't update the data field on the user interface.
if (mNotifyCharacteristic != null) {
mBluetoothLeService.setCharacteristicNotification(
mNotifyCharacteristic, false);
mNotifyCharacteristic = null;
}
mBluetoothLeService.readCharacteristic(characteristic);
showDialog("reading");
}
if ((charaProp | BluetoothGattCharacteristic.PROPERTY_WRITE) > 0) {
// If there is an active notification on a characteristic, clear
// it first so it doesn't update the data field on the user interface.
if (mNotifyCharacteristic != null) {
mBluetoothLeService.setCharacteristicNotification(
mNotifyCharacteristic, false);
mNotifyCharacteristic = null;
}
mBluetoothLeService.writeCharacteristic(characteristic);
showDialog("writing");
//characteristic.setValue(bytes);
//characteristic.setValue("testing");
//characteristic.setWriteType(BluetoothGattCharacteristic.PERMISSION_WRITE);
}
if ((charaProp | BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) {
mNotifyCharacteristic = characteristic;
mBluetoothLeService.setCharacteristicNotification(
characteristic, true);
}
byte[] value = {0x00, (byte) (0xB9) , 0x0D, (byte) (0x90), 0x2F};
if(!characteristic.setValue(value))
{
Log.w(TAG, "Couldn't set characteristic's local value");
//return;
}
characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
/*if(!writeCharacteristic.writeCharacteristic(characteristic))
{
Log.w(TAG, "Couldn't write characteristic");
}*/
return true;
}
return false;
}
};
The following code is write characteristic using byte[] data:
public boolean writeCharacteristic(){
//check mBluetoothGatt is available
if (mBluetoothGatt == null) {
Log.e(TAG, "lost connection");
return false;
}
BluetoothGattService Service = mBluetoothGatt.getService(your Services);
if (Service == null) {
Log.e(TAG, "service not found!");
return false;
}
BluetoothGattCharacteristic charac = Service
.getCharacteristic(your characteristic);
if (charac == null) {
Log.e(TAG, "char not found!");
return false;
}
byte[] value = new byte[1];
value[0] = (byte) (21 & 0xFF);
charac.setValue(value);
boolean status = mBluetoothGatt.writeCharacteristic(charac);
return status;
}
Please note that the logic OR in:
if ((charaProp | BluetoothGattCharacteristic.PROPERTY_READ) > 0)" in the original post should be a logic AND for the permission check to work. Same for the second charaProp comparison. Otherwise bot statements are true regardless of the actual permission flag.
The following code is write characteristic using string data in utf-8 format:
public void writeCharacteristic(BluetoothGattCharacteristic characteristic,
String data) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
Log.i(TAG, "characteristic " + characteristic.toString());
try {
Log.i(TAG, "data " + URLEncoder.encode(data, "utf-8"));
characteristic.setValue(URLEncoder.encode(data, "utf-8"));
// TODO
mBluetoothGatt.writeCharacteristic(characteristic);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
Hope it helps!
public boolean writeCharacteristic(byte value[],int type){
//check mBluetoothGatt is available
if (mBluetoothGatt == null) {
Log.e(TAG, "lost connection");
return false;
}
BluetoothGattService Service = mBluetoothGatt.getService(UUID_SIMPLESERVICE);
if (Service == null) {
Log.e(TAG, "service not found!");
//////////NO service found...........
return false;
}
BluetoothGattCharacteristic charac1 = null;
boolean status1 = false;
if(type==1) {
charac1 = Service.getCharacteristic(UUID_PORT1);
charac1.setValue(value);
status1 = mBluetoothGatt.writeCharacteristic(charac1);
Log.v("________BLESERVICE____", "___WRITE CHARATERISTICS STATUS:_________"+status1);
onReliableWriteCompleted(status1);
}
if (charac1 == null) {
Log.e(TAG, "char not found!");
return false;
}
Log.v("___TYPE___","______________________"+type);
return status1;
}
I am trying to transfer data from my android device to FPGA board. The android device supports the USB host mode and the connected FPGA board uses RS_232 port. So I got a USB-RS232 converter device(CP210x) for the connection. I coded the transfer as mentioned on this page: http://developer.android.com/guide/topics/connectivity/usb/host.html My code is:
public class MainActivity extends Activity
implements View.OnClickListener, Runnable {
private static final String TAG = "TransferData";
private Button sendB;
private UsbManager mUsbManager;
private UsbDevice mDevice;
private UsbDeviceConnection mConnection;
private UsbEndpoint mEndpointIntr;
private static final char DATA = 'A';
static UsbDevice device;
static int TIMEOUT = 0;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sendB = (Button)findViewById(R.id.send);
sendB.setOnClickListener(this);
mUsbManager = (UsbManager)getSystemService(Context.USB_SERVICE);
}
#Override
public void onPause() {
super.onPause();
}
#Override
public void onResume() {
super.onResume();
Intent intent = getIntent();
Log.d(TAG, "intent: " + intent);
String action = intent.getAction();
device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {
setDevice(device);
} else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) {
if (mDevice != null && mDevice.equals(device)) {
setDevice(null);
}
}
}
#Override
public void onDestroy() {
super.onDestroy();
}
private void setDevice(UsbDevice device) {
Log.d(TAG, "setDevice " + device);
if (device.getInterfaceCount() != 1) {
Log.e(TAG, "could not find interface");
return;
}
else Log.w(TAG, "found interface");
UsbInterface intf = device.getInterface(0);
// device should have one endpoint
if (intf.getEndpointCount() == 0) {
Log.e(TAG, "could not find endpoint");
return;
}
else Log.w(TAG, "found endpoint");
// endpoint should be of type interrupt
Log.w("endpoint", "" + intf.getEndpointCount());
UsbEndpoint ep = intf.getEndpoint(1);
if (ep.getType() != UsbConstants.USB_ENDPOINT_XFER_BULK) {
Log.e(TAG, "endpoint is not interrupt type");
return;
}
else Log.w(TAG, "endpoint is interrupt");
mDevice = device;
mEndpointIntr = ep;
if (device != null) {
UsbDeviceConnection connection = mUsbManager.openDevice(device);
if (connection != null && connection.claimInterface(intf, true)) {
Log.d(TAG, "open SUCCESS");
mConnection = connection;
Thread thread = new Thread(this);
thread.start();
} else {
Log.d(TAG, "open FAIL");
mConnection = null;
}
}
}
private void sendCommand(char control) {
if (mConnection != null) {
byte[] message = new byte[1];
message[0] = (byte)control;
// Send command via a control request on endpoint zero
UsbInterface intf = device.getInterface(0);
UsbEndpoint endpoint = intf.getEndpoint(1);
mConnection.claimInterface(intf,true);
int res = mConnection.bulkTransfer(endpoint, message, message.length, TIMEOUT);
Log.w("data sent","result " + res);
}
}
public void onClick(View v) {
if (v == sendB) {
sendCommand(DATA);
}
}
#Override
public void run() {
ByteBuffer buffer = ByteBuffer.allocate(1);
UsbRequest request = new UsbRequest();
request.initialize(mConnection, mEndpointIntr);
byte status = -1;
request.queue(buffer, 1);
// send poll status command
sendCommand(DATA);
// wait for status event
if (mConnection.requestWait() == request) {
byte newStatus = buffer.get(0);
if (newStatus != status) {
Log.d(TAG, "got status " + newStatus);
status = newStatus;
}
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
} else {
Log.e(TAG, "requestWait failed, exiting");
}
}
I get success in opening device and I get send result as 1. But no data received is reflected as the FPGA board. What am I doing wromg?
Try to switch RX with TX on FPGA. Did other communcation work with this connection?
Is there a design on the FPGA which will serve the UART?
I'm a beginner android programmer who is trying to set up some USB functionality with my tablet and a device. My program uses an Intent filter to find the device. I took the Android's MissileLauncherActivity.java example and rewrote it. I am getting a "could not find endpoint" error in logcat. Is there something wrong with my code, or could it be my device? LogCat is finding the error in the setDevice method where it is trying to find the OUT endpoint. Here is the code:
public class UsbTestActivity extends Activity implements Runnable {
private UsbManager mUsbManager;
private UsbDevice mDevice;
private UsbDeviceConnection mConnection;
private UsbEndpoint mEndpointIntr;
private static final String TAG = "UsbTestActivity";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mUsbManager = (UsbManager)getSystemService(Context.USB_SERVICE);
}
#Override
public void onPause(){
super.onPause();
}
#Override
public void onResume(){
super.onResume();
Intent intent = getIntent();
Log.d(TAG, "intent: " + intent);
String action = intent.getAction();
UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {
setDevice(device);
} else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) {
if (mDevice != null && mDevice.equals(device)) {
setDevice(null);
}
}
}
#Override
public void onDestroy() {
super.onDestroy();
}
public void setDevice(UsbDevice device){
Log.d(TAG, "setDevice " + device);
if (device.getInterfaceCount() != 1) {
Log.e(TAG, "could not find interface");
return;
}
UsbInterface intf = device.getInterface(0);
// device should have one endpoint
if (intf.getEndpointCount() != 1) {
Log.e(TAG, "could not find endpoint");
return;
}
System.out.println("Got endpoint");
// endpoint should be of type interrupt
UsbEndpoint ep = intf.getEndpoint(0);
if (ep.getType() != UsbConstants.USB_ENDPOINT_XFER_INT) {
Log.e(TAG, "endpoint is not interrupt type");
return;
}
mDevice = device;
mEndpointIntr = ep;
if (device != null) {
UsbDeviceConnection connection = mUsbManager.openDevice(device);
if (connection != null && connection.claimInterface(intf, true)) {
Log.d(TAG, "open SUCCESS");
mConnection = connection;
Thread thread = new Thread(this);
thread.start();
} else {
Log.d(TAG, "open FAIL");
mConnection = null;
}
}
}
private void sendCommand(int control) {
synchronized (this) {
if (mConnection != null) {
byte[] message = new byte[1];
message[0] = (byte)control;
// Send command via a control request on endpoint zero
if(mConnection.controlTransfer(0x21, 0x9, 0x200, 0, message, message.length, 0) > 0){
Log.d(TAG, "Sending Failed");
}
}
}
}
public void run() {
ByteBuffer buffer = ByteBuffer.allocate(1);
UsbRequest request = new UsbRequest();
request.initialize(mConnection, mEndpointIntr);
byte status = -1;
while (true) {
// queue a request on the interrupt endpoint
request.queue(buffer, 1);
// send poll status command
if (mConnection.requestWait() == request) {
byte newStatus = buffer.get(0);
if (newStatus != status) {
Log.d(TAG, "got status " + newStatus);
status = newStatus;
sendCommand(7);
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {
}
} else {
Log.e(TAG, "requestWait failed, exiting");
break;
}
}
}
}
// device should have one endpoint
if (intf.getEndpointCount() != 1) {
Log.e(TAG, "could not find endpoint");
return;
}
Looks like you are trying to work with a USB HID device and its OUT endpoint. But HID mandates the IN endpoint to be present - so getEndpointCount() will most likely return 2 instead of one. You will need to check which is the IN and which is OUT.