Android和低功耗蓝牙（BLE）
问题描述：
我很努力从定制蓝牙低功耗设备读取/发送数据。我正在使用Microchip RN4020蓝牙模块。Android和低功耗蓝牙（BLE）
我发现的每个教程或示例都解释了如何将移动应用程序连接到设备，但我没有找到如何实际与其进行交互。 因此，我正是可以做和不能做我的应用程序。
每一个特征目前我做了以下内容：
gatt.readCharacteristic(services.get(i).getCharacteristics().get(j));
这是结果，当我打印的价值观：
getStringValue= Mobi_F934��
getStringValue= null
getStringValue= ����d���
getStringValue= 001EC030F934
getStringValue= 2.1
getStringValue= 1.10
getStringValue= 1.10
getStringValue= Microchip
getStringValue= RN4020
getStringValue=
getStringValue=
我不知道这是重要的或者不...
如何读取从BLE设备发送的数据？
编辑：我的Android代码
@TargetApi(21)
public class MainActivity extends ActionBarActivity {
private BluetoothAdapter mBluetoothAdapter;
private int REQUEST_ENABLE_BT = 1;
private Handler mHandler;
private static final long SCAN_PERIOD = 10000;
private BluetoothLeScanner mLEScanner;
private ScanSettings settings;
private List<ScanFilter> filters;
private BluetoothGatt mGatt;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mHandler = new Handler();
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
Toast.makeText(this, "BLE Not Supported",
Toast.LENGTH_SHORT).show();
finish();
}
// Initializes Bluetooth adapter
final BluetoothManager bluetoothManager =
(BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = bluetoothManager.getAdapter();
}
@Override
protected void onResume() {
super.onResume();
// Ensures Bluetooth is available on the device and it is enabled. If not,
// displays a dialog requesting user permission to enable Bluetooth.
if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
} else {
if (Build.VERSION.SDK_INT >= 21) {
mLEScanner = mBluetoothAdapter.getBluetoothLeScanner();
settings = new ScanSettings.Builder()
.setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
.build();
filters = new ArrayList<ScanFilter>();
}
scanLeDevice(true);
}
}
@Override
protected void onPause() {
super.onPause();
if (mBluetoothAdapter != null && mBluetoothAdapter.isEnabled()) {
scanLeDevice(false);
}
}
@Override
protected void onDestroy() {
if (mGatt == null) {
return;
}
mGatt.close();
mGatt = null;
super.onDestroy();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_ENABLE_BT) {
if (resultCode == Activity.RESULT_CANCELED) {
//Bluetooth not enabled.
finish();
return;
}
}
super.onActivityResult(requestCode, resultCode, data);
}
private void scanLeDevice(final boolean enable) {
if (enable) {
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
}
}, SCAN_PERIOD);
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.startLeScan(mLeScanCallback);
} else {
mLEScanner.startScan(filters, settings, mScanCallback);
}
} else {
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
}
}
private ScanCallback mScanCallback = new ScanCallback() {
@Override
public void onScanResult(int callbackType, ScanResult result) {
Log.e("callbackType", "MAX " + String.valueOf(callbackType));
Log.e("result", "MAX " + result.toString());
BluetoothDevice btDevice = result.getDevice();
connectToDevice(btDevice);
}
@Override
public void onBatchScanResults(List<ScanResult> results) {
for (ScanResult sr : results) {
Log.e("ScanResult - Results", "MAX " + sr.toString());
}
}
@Override
public void onScanFailed(int errorCode) {
Log.e("Scan Failed", "MAX " + "Error Code: " + errorCode);
}
};
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi,
byte[] scanRecord) {
runOnUiThread(new Runnable() {
@Override
public void run() {
Log.e("onLeScan", "MAX " + device.toString());
connectToDevice(device);
}
});
}
};
public void connectToDevice(BluetoothDevice device) {
if (mGatt == null) {
mGatt = device.connectGatt(this, false, gattCallback);
scanLeDevice(false);// will stop after first device detection
}
}
private final BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
Log.e("onConnectionStateChange", "MAX " + "Status: " + status);
switch (newState) {
case BluetoothProfile.STATE_CONNECTED:
Log.e("gattCallback", "MAX " + "STATE_CONNECTED");
gatt.discoverServices();
break;
case BluetoothProfile.STATE_DISCONNECTED:
Log.e("gattCallback", "MAX " + "STATE_DISCONNECTED");
break;
default:
Log.e("gattCallback", "MAX " + "STATE_OTHER");
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
List<BluetoothGattService> services = gatt.getServices();
Log.e("onServicesDiscovered", "MAX " + services.toString());
/*
for(int i = 0; i < services.size(); i++){
for (int j = 0; j < services.get(i).getCharacteristics().size(); j++){
Log.e("MAX", "i= " + i + " j= " + j);
gatt.readCharacteristic(services.get(i).getCharacteristics().get
(j));
}
}
*/
gatt.readCharacteristic(services.get(0).getCharacteristics().get(0));
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt,
BluetoothGattCharacteristic
characteristic, int status) {
Log.e("onCharacteristicRead", "MAX " + characteristic.toString());
Log.e("onCharacteristicRead", "MAX " +characteristic.getStringValue(0));
//gatt.disconnect();
}
};
}
编辑2：我的Arduino代码
#include <SoftwareSerial.h>
/* Set up BT to arduino uno
BT RN4020 Arduino Uno
------------------------------------------------
Red 3.3V
Green GND
Yellow(RX) TX (digital pin 1)
Orange(TX) RX (digital pin 0)
White PIN 8 (!) This is not GND (!)
Blue 3.3V (Ioref can also be used)
*/
/*
-----------------------------------------------------------------------------
-----EXPLANATION PROGRAM-----------------------------------------------------
----------------------------
Eerst wordt de BT module geïnitialiseerd door verschillende commando's door te
sturen. Bij elk commando wordt gecheckt of de BT module het juiste antwoord
heeft teruggestuurd.
De initialisatie moet gebeuren in CMD mode, de CMD/MLDP pin moet laag zijn. Na
de initialisatie checken we tot de BT module is geconnecteerd met het device.
Als de BT module geconnecteerd is zetten we deze uit CMD mode en in MLDP mode
om het verzenden en ontvangen van data te ondersteunen. Daarna zenden we om de
seconde de string 'test' door.
Dit gebeurt zolang het device geconnecteerd is met de BT module.
------------------------------------------------------------------------------
------------------------------------------------------------------------------
-----------------------------
*/
int CMD_MLD_pin = 8; // IO pin for CMD/MLDP pin (LOW --> CMD, HIGH --> MLDP)
void setup() // Initialising BT RN4020
{
pinMode(CMD_MLD_pin, OUTPUT);
digitalWrite(CMD_MLD_pin, LOW); // put CMD/MLDP pin LOW for CMD mode
delay(5000);
/* Initialize Bluetooth */
Serial.begin(115200); // Set up serial connection with required baud rate of
// 115200
delay(1500);
Serial.println("R,1"); //Reboot
while(!Serial.find("Reboot")){} // Waiting until BT RN4020 responds the
required string
while(!Serial.find("CMD")){}
//delay(2000);
Serial.println("SF,1"); // Factory reset
while(!Serial.find("AOK")){}
//delay(1500);
Serial.println("SR,32000000"); // Set device as peripheral
while(!Serial.find("AOK")){}
Serial.println("S-, Mobi"); // Change name of BT
while(!Serial.find("AOK")){}
//delay(1500);
Serial.println("R,1"); // Reboot to make changes effective
while(!Serial.find("Reboot")){}
while(!Serial.find("CMD")){}
//delay(2000);
}
void loop()
{
// Wait until the device responds it is connected
// If the device is connected we will send every second the string 'test'
while(!Serial.find("Connected")){} // Wait until BT RN4020 is connected to a
// device
digitalWrite(CMD_MLD_pin, HIGH); // Go to MLDP to support data stream
while(!Serial.find("MLDP")){} // Wait until BT RN4020 is effectively in MLDP
// mode
delay(500);
while (!Serial.find("Connection End")) // Send string to BTRN4020 while the
// BT RN4020 is conected to a device
{
Serial.println("test");
delay(1000);
}
}
答
问了几个月后，我设法解决了我的问题。那时我忘了分享我的解决方案。无论如何，迟到比从未更好！
这是我在BLE上测试android-TI sensortag通信时编写的一些代码。
完整的例子可在https://github.com/maxhelskens/SmergyBicycle
package com.example.max.smergy;
import android.annotation.TargetApi;
import android.app.Activity;
import android.app.ProgressDialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattDescriptor;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothManager;
import android.bluetooth.BluetoothProfile;
import android.bluetooth.le.BluetoothLeScanner;
import android.bluetooth.le.ScanCallback;
import android.bluetooth.le.ScanFilter;
import android.bluetooth.le.ScanResult;
import android.bluetooth.le.ScanSettings;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.util.SparseArray;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
@TargetApi(21)
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
private static final String DEVICE_NAME = "SensorTag";
/* Humidity Service */
private static final UUID HUMIDITY_SERVICE = UUID.fromString("F000AA20-0451-4000-B000-000000000000");
private static final UUID HUMIDITY_DATA_CHAR = UUID.fromString("f000aa21-0451-4000-b000-000000000000");
private static final UUID HUMIDITY_CONFIG_CHAR = UUID.fromString("f000aa22-0451-4000-b000-000000000000");
/* magneto Service */
private static final UUID MAGNETO_SERVICE = UUID.fromString("F000AA80-0451-4000-B000-000000000000");
private static final UUID MAGNETO_DATA_CHAR = UUID.fromString("f000aa81-0451-4000-b000-000000000000");
private static final UUID MAGNETO_CONFIG_CHAR = UUID.fromString("f000aa82-0451-4000-b000-000000000000");
/* Barometric Pressure Service */
private static final UUID PRESSURE_SERVICE = UUID.fromString("f000aa40-0451-4000-b000-000000000000");
private static final UUID PRESSURE_DATA_CHAR = UUID.fromString("f000aa41-0451-4000-b000-000000000000");
private static final UUID PRESSURE_CONFIG_CHAR = UUID.fromString("f000aa42-0451-4000-b000-000000000000");
private static final UUID PRESSURE_CAL_CHAR = UUID.fromString("f000aa43-0451-4000-b000-000000000000");
/* Client Configuration Descriptor */
private static final UUID CONFIG_DESCRIPTOR = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb");
private BluetoothAdapter mBluetoothAdapter;
private SparseArray<BluetoothDevice> mDevices;
private BluetoothGatt mGatt;
private TextView mTemperature, mHumidity, mPressure;
private ProgressDialog mProgress;
private int REQUEST_ENABLE_BT = 1;
private BluetoothLeScanner mLEScanner;
private ScanSettings settings;
private List<ScanFilter> filters;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setProgressBarIndeterminate(true);
// Find the toolbar view inside the activity layout
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
// Sets the Toolbar to act as the ActionBar for this Activity window.
// Make sure the toolbar exists in the activity and is not null
setSupportActionBar(toolbar);
/*
* We are going to display the results in some text fields
*/
mTemperature = (TextView) findViewById(R.id.text_temperature);
mHumidity = (TextView) findViewById(R.id.text_humidity);
mPressure = (TextView) findViewById(R.id.text_pressure);
//Check if BLE is supported
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
Toast.makeText(this, "BLE Not Supported",
Toast.LENGTH_SHORT).show();
finish();
}
final BluetoothManager bluetoothManager =
(BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = bluetoothManager.getAdapter();
mDevices = new SparseArray<BluetoothDevice>();
/*
* A progress dialog will be needed while the connection process is
* taking place
*/
mProgress = new ProgressDialog(this);
mProgress.setIndeterminate(true);
mProgress.setCancelable(false);
}
@Override
protected void onResume() {
super.onResume();
if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
} else {
if (Build.VERSION.SDK_INT >= 21) {
mLEScanner = mBluetoothAdapter.getBluetoothLeScanner();
settings = new ScanSettings.Builder()
.setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
.build();
filters = new ArrayList<ScanFilter>();
}
}
clearDisplayValues();
}
@Override
protected void onPause() {
super.onPause();
//Make sure dialog is hidden
mProgress.dismiss();
//Cancel any scans in progress
mHandler.removeCallbacks(mStopRunnable);
mHandler.removeCallbacks(mStartRunnable);
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
}
@Override
protected void onStop() {
super.onStop();
//Disconnect from any active tag connection
if (mGatt != null) {
mGatt.close();
mGatt = null;
}
}
@Override
protected void onDestroy() {
if (mGatt == null) {
return;
}
mGatt.close();
mGatt = null;
super.onDestroy();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_ENABLE_BT) {
if (resultCode == Activity.RESULT_CANCELED) {
//Bluetooth not enabled.
finish();
return;
}
}
super.onActivityResult(requestCode, resultCode, data);
}
// Menu icons are inflated just as they were with actionbar
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
//Add any device elements we've discovered to the overflow menu
for (int i=0; i < mDevices.size(); i++) {
BluetoothDevice device = mDevices.valueAt(i);
menu.add(0, mDevices.keyAt(i), 0, device.getName());
}
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.bluetoothSearch:
mDevices.clear();
startScan();
//scanLeDevice(true);
return true;
default:
//Obtain the discovered device to connect with
BluetoothDevice device = mDevices.get(item.getItemId());
Log.i(TAG, "Connecting to " + device.getName());
/*
* Make a connection with the device
*/
connectToDevice(device);
//Display progress UI
mHandler.sendMessage(Message.obtain(null, MSG_PROGRESS, "Connecting to " + device.getName() + "..."));
return super.onOptionsItemSelected(item);
}
}
private void clearDisplayValues() {
mTemperature.setText("---");
mHumidity.setText("---");
mPressure.setText("---");
}
private Runnable mStopRunnable = new Runnable() {
@Override
public void run() {
stopScan();
}
};
private Runnable mStartRunnable = new Runnable() {
@Override
public void run() {
startScan();
}
};
private void startScan() {
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.startLeScan(mLeScanCallback);
} else {
mLEScanner.startScan(filters, settings, mScanCallback);
}
setProgressBarIndeterminateVisibility(true);
mHandler.postDelayed(mStopRunnable, 2500);
}
private void stopScan() {
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
setProgressBarIndeterminateVisibility(false);
}
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
Log.i("onLeScan", device.toString());
mDevices.put(device.hashCode(), device);
//Update the overflow menu
invalidateOptionsMenu();
}
};
/*
private void scanLeDevice(final boolean enable) {
if (enable) {
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
}
}, SCAN_PERIOD);
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.startLeScan(mLeScanCallback);
} else {
mLEScanner.startScan(filters, settings, mScanCallback);
}
} else {
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
}
}
*/
private ScanCallback mScanCallback = new ScanCallback() {
@Override
public void onScanResult(int callbackType, ScanResult result) {
Log.i("callbackType", String.valueOf(callbackType));
Log.i("result", result.toString());
BluetoothDevice btDevice = result.getDevice();
mDevices.put(btDevice.hashCode(), btDevice);
//Update the overflow menu
invalidateOptionsMenu();
}
@Override
public void onBatchScanResults(List<ScanResult> results) {
for (ScanResult sr : results) {
Log.i("ScanResult - Results", sr.toString());
}
}
@Override
public void onScanFailed(int errorCode) {
Log.e("Scan Failed", "Error Code: " + errorCode);
}
};
public void connectToDevice(BluetoothDevice device) {
if (mGatt == null) {
mGatt = device.connectGatt(this, false, gattCallback);
stopScan();
}
}
/*
* In this callback, we've created a bit of a state machine to enforce that only
* one characteristic be read or written at a time until all of our sensors
* are enabled and we are registered to get notifications.
*/
private final BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
/* State Machine Tracking */
private int mState = 0;
private void reset() { mState = 0; }
private void advance() { mState++; }
/*
* Send an enable command to each sensor by writing a configuration
* characteristic. This is specific to the SensorTag to keep power
* low by disabling sensors you aren't using.
*/
private void enableNextSensor(BluetoothGatt gatt) {
BluetoothGattCharacteristic characteristic;
switch (mState) {
/*
case 0:
Log.d(TAG, "Enabling pressure cal");
characteristic = gatt.getService(PRESSURE_SERVICE)
.getCharacteristic(PRESSURE_CONFIG_CHAR);
characteristic.setValue(new byte[] {0x02});
break;
case 1:
Log.d(TAG, "Enabling pressure");
characteristic = gatt.getService(PRESSURE_SERVICE)
.getCharacteristic(PRESSURE_CONFIG_CHAR);
characteristic.setValue(new byte[] {0x01});
break; */
case 0:
Log.d(TAG, "Enabling humidity");
characteristic = gatt.getService(HUMIDITY_SERVICE)
.getCharacteristic(HUMIDITY_CONFIG_CHAR);
characteristic.setValue(new byte[] {0x01});
break;
case 1:
Log.d(TAG, "Enabling magneto");
characteristic = gatt.getService(MAGNETO_SERVICE)
.getCharacteristic(MAGNETO_CONFIG_CHAR);
characteristic.setValue(new byte[] {(byte)0x7F, (byte)0x00});
break;
default:
mHandler.sendEmptyMessage(MSG_DISMISS);
Log.i(TAG, "All Sensors Enabled");
return;
}
gatt.writeCharacteristic(characteristic);
}
/*
* Read the data characteristic's value for each sensor explicitly
*/
private void readNextSensor(BluetoothGatt gatt) {
BluetoothGattCharacteristic characteristic;
switch (mState) {
/*
case 0:
Log.d(TAG, "Reading pressure cal");
characteristic = gatt.getService(PRESSURE_SERVICE)
.getCharacteristic(PRESSURE_CAL_CHAR);
break;
case 1:
Log.d(TAG, "Reading pressure");
characteristic = gatt.getService(PRESSURE_SERVICE)
.getCharacteristic(PRESSURE_DATA_CHAR);
break;*/
case 0:
Log.d(TAG, "Reading humidity");
characteristic = gatt.getService(HUMIDITY_SERVICE)
.getCharacteristic(HUMIDITY_DATA_CHAR);
break;
case 1:
Log.d(TAG, "Reading magneto");
characteristic = gatt.getService(MAGNETO_SERVICE)
.getCharacteristic(MAGNETO_DATA_CHAR);
break;
default:
mHandler.sendEmptyMessage(MSG_DISMISS);
Log.i(TAG, "All Sensors Enabled");
return;
}
gatt.readCharacteristic(characteristic);
}
/*
* Enable notification of changes on the data characteristic for each sensor
* by writing the ENABLE_NOTIFICATION_VALUE flag to that characteristic's
* configuration descriptor.
*/
private void setNotifyNextSensor(BluetoothGatt gatt) {
BluetoothGattCharacteristic characteristic;
switch (mState) {
/*
case 0:
Log.d(TAG, "Set notify pressure cal");
characteristic = gatt.getService(PRESSURE_SERVICE)
.getCharacteristic(PRESSURE_CAL_CHAR);
break;
case 1:
Log.d(TAG, "Set notify pressure");
characteristic = gatt.getService(PRESSURE_SERVICE)
.getCharacteristic(PRESSURE_DATA_CHAR);
break;*/
case 0:
Log.d(TAG, "Set notify humidity");
characteristic = gatt.getService(HUMIDITY_SERVICE)
.getCharacteristic(HUMIDITY_DATA_CHAR);
break;
case 1:
Log.d(TAG, "Set notify magneto");
characteristic = gatt.getService(MAGNETO_SERVICE)
.getCharacteristic(MAGNETO_DATA_CHAR);
break;
default:
mHandler.sendEmptyMessage(MSG_DISMISS);
Log.i(TAG, "All Sensors Enabled");
return;
}
//Enable local notifications
gatt.setCharacteristicNotification(characteristic, true);
//Enabled remote notifications
BluetoothGattDescriptor desc = characteristic.getDescriptor(CONFIG_DESCRIPTOR);
desc.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
gatt.writeDescriptor(desc);
}
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
Log.i("onConnectionStateChange", "Status: " + status);
if (status == BluetoothGatt.GATT_SUCCESS && newState == BluetoothProfile.STATE_CONNECTED) {
/*
* Once successfully connected, we must next discover all the services on the
* device before we can read and write their characteristics.
*/
gatt.discoverServices();
mHandler.sendMessage(Message.obtain(null, MSG_PROGRESS, "Discovering Services..."));
} else if (status == BluetoothGatt.GATT_SUCCESS && newState == BluetoothProfile.STATE_DISCONNECTED) {
/*
* If at any point we disconnect, send a message to clear the weather values
* out of the UI
*/
mHandler.sendEmptyMessage(MSG_CLEAR);
} else if (status != BluetoothGatt.GATT_SUCCESS) {
/*
* If there is a failure at any stage, simply disconnect
*/
gatt.close();
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
List<BluetoothGattService> services = gatt.getServices();
Log.i("onServicesDiscovered", services.toString());
mHandler.sendMessage(Message.obtain(null, MSG_PROGRESS, "Enabling Sensors..."));
/*
* With services discovered, we are going to reset our state machine and start
* working through the sensors we need to enable
*/
reset();
enableNextSensor(gatt);
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
Log.i("onCharacteristicRead", characteristic.toString());
//For each read, pass the data up to the UI thread to update the display
if (HUMIDITY_DATA_CHAR.equals(characteristic.getUuid())) {
mHandler.sendMessage(Message.obtain(null, MSG_HUMIDITY, characteristic));
}
if (MAGNETO_DATA_CHAR.equals(characteristic.getUuid())) {
mHandler.sendMessage(Message.obtain(null, MSG_MAGNETO, characteristic));
}
if (PRESSURE_DATA_CHAR.equals(characteristic.getUuid())) {
mHandler.sendMessage(Message.obtain(null, MSG_PRESSURE, characteristic));
}
if (PRESSURE_CAL_CHAR.equals(characteristic.getUuid())) {
mHandler.sendMessage(Message.obtain(null, MSG_PRESSURE_CAL, characteristic));
}
//After reading the initial value, next we enable notifications
setNotifyNextSensor(gatt);
}
@Override
public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
//After writing the enable flag, next we read the initial value
readNextSensor(gatt);
}
@Override
public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
/*
* After notifications are enabled, all updates from the device on characteristic
* value changes will be posted here. Similar to read, we hand these up to the
* UI thread to update the display.
*/
if (HUMIDITY_DATA_CHAR.equals(characteristic.getUuid())) {
mHandler.sendMessage(Message.obtain(null, MSG_HUMIDITY, characteristic));
}
if (MAGNETO_DATA_CHAR.equals(characteristic.getUuid())) {
mHandler.sendMessage(Message.obtain(null, MSG_MAGNETO, characteristic));
}
if (PRESSURE_DATA_CHAR.equals(characteristic.getUuid())) {
mHandler.sendMessage(Message.obtain(null, MSG_PRESSURE, characteristic));
}
if (PRESSURE_CAL_CHAR.equals(characteristic.getUuid())) {
mHandler.sendMessage(Message.obtain(null, MSG_PRESSURE_CAL, characteristic));
}
}
@Override
public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
//Once notifications are enabled, we move to the next sensor and start over with enable
advance();
enableNextSensor(gatt);
}
@Override
public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
Log.d(TAG, "Remote RSSI: " + rssi);
}
private String connectionState(int status) {
switch (status) {
case BluetoothProfile.STATE_CONNECTED:
return "Connected";
case BluetoothProfile.STATE_DISCONNECTED:
return "Disconnected";
case BluetoothProfile.STATE_CONNECTING:
return "Connecting";
case BluetoothProfile.STATE_DISCONNECTING:
return "Disconnecting";
default:
return String.valueOf(status);
}
}
};
/*
* We have a Handler to process event results on the main thread
*/
private static final int MSG_HUMIDITY = 101;
private static final int MSG_PRESSURE = 102;
private static final int MSG_PRESSURE_CAL = 103;
private static final int MSG_MAGNETO = 104;
private static final int MSG_PROGRESS = 201;
private static final int MSG_DISMISS = 202;
private static final int MSG_CLEAR = 301;
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
BluetoothGattCharacteristic characteristic;
switch (msg.what) {
case MSG_HUMIDITY:
characteristic = (BluetoothGattCharacteristic) msg.obj;
if (characteristic.getValue() == null) {
Log.w(TAG, "Error obtaining humidity value");
return;
}
updateHumidityValues(characteristic);
break;
case MSG_MAGNETO:
characteristic = (BluetoothGattCharacteristic) msg.obj;
if (characteristic.getValue() == null) {
Log.w(TAG, "Error obtaining magneto value");
return;
}
updateMagnetoValues(characteristic);
break;
case MSG_PRESSURE:
characteristic = (BluetoothGattCharacteristic) msg.obj;
if (characteristic.getValue() == null) {
Log.w(TAG, "Error obtaining pressure value");
return;
}
updatePressureValue(characteristic);
break;
case MSG_PRESSURE_CAL:
characteristic = (BluetoothGattCharacteristic) msg.obj;
if (characteristic.getValue() == null) {
Log.w(TAG, "Error obtaining cal value");
return;
}
updatePressureCals(characteristic);
break;
case MSG_PROGRESS:
mProgress.setMessage((String) msg.obj);
if (!mProgress.isShowing()) {
mProgress.show();
}
break;
case MSG_DISMISS:
mProgress.hide();
break;
case MSG_CLEAR:
clearDisplayValues();
break;
}
}
};
/* Methods to extract sensor data and update the UI */
private void updateHumidityValues(BluetoothGattCharacteristic characteristic) {
double humidity = SensorTagData.extractHumidity(characteristic);
mHumidity.setText(String.format("%.0f%%", humidity));
}
ArrayList<Double> magnets = new ArrayList<>();
double average = 0;
int count = -1;
int wait5 = 0;
private void updateMagnetoValues(BluetoothGattCharacteristic characteristic) {
double magnet = SensorTagData.extractMagnetoX(characteristic);
Log.e("MAGNETO", "" + magnet);
magnet = Math.abs(magnet);
if (wait5 == 0) {
if (magnet > average + 300 || magnet < average - 300) {
wait5 = 6;
count ++;
mPressure.setText("" + count);
}
}
else {
wait5 --;
}
if (magnets.size() >= 5) {
magnets.remove(0);
}
magnets.add(magnet);
double sum = 0;
for (int i = 0; i < magnets.size(); i++) {
sum += magnets.get(i);
}
average = sum/magnets.size();
average = magnets.get(2);
//mHumidity.setText(String.format("%.0f%%", humidity));
}
private int[] mPressureCals;
private void updatePressureCals(BluetoothGattCharacteristic characteristic) {
mPressureCals = SensorTagData.extractCalibrationCoefficients(characteristic);
}
private void updatePressureValue(BluetoothGattCharacteristic characteristic) {
if (mPressureCals == null) return;
double pressure = SensorTagData.extractBarometer(characteristic, mPressureCals);
double temp = SensorTagData.extractBarTemperature(characteristic, mPressureCals);
mTemperature.setText(String.format("%.1f\u00B0C", temp));
mPressure.setText(String.format("%.2f", pressure));
}
}
答
嗯，我认为你应该做如何使用的特点更多的阅读。你的芯片在默认情况下有很多特征，主要包含来自芯片的信息。为了发送和接收数据，您必须首先对芯片进行编程，以便通过特定的特性发送数据，并通过其他特定的特性接收数据。
某些芯片具有默认的Rx和Tx特性，您应该使用它们来发送和接收数据。这些特性充当BLE与芯片上Tx和Rx引脚之间的流水线，并将简单回显所有数据。
或者，您可以在BLE服务上创建自己的特征，并编写自己的发送和接收协议。
让我给你举一个简单的例子：
假设您正在使用芯片的默认特性发送数据。这些数据必须以小块发送，例如20个字节。要在Android上读取此数据，您必须首先获取该特征的描述符并启用通知。这将告诉Android听取该特征并监控变化。
characteristic = gatt.getService(UUID.fromString(SERVICE_UUID)).getCharacteristic(UUID.fromString(CHARACTERISTIC_UUID)); //Find you characteristic
mGatt.setCharacteristicNotification(characteristic, true); //Tell you gatt client that you want to listen to that characteristic
List<BluetoothGattDescriptor> descriptors = characteristic.getDescriptors(); //find the descriptors on the characteristic
BluetoothGattDescriptor descriptor = descriptors.get(1); //get the right descriptor for setting notifications
descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
mGatt.writeDescriptor(descriptor); //apply these changes to the ble chip to tell it we are ready for the data
这样做了以后，你就可以使用onCharacteristicChanged方法来读取数据：
@Override
public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
super.onCharacteristicChanged(gatt, characteristic);
String data = characteristic.getStringValue(0);
}
发送的数据将是一个有点简单。一旦你找到的特征，你就必须以块的形式写入数据到特点：
byte[] value = new byte[1];
value[0] = (byte) (21 & 0xFF); //your data
characteristic.setValue(value); //assign the new data value to the characteristic
boolean success = mBluetoothGatt.writeCharacteristic(charac); //write to the chip
一旦写入，该芯片将刷新特性，将数据发送到芯片的TX脚上。
编辑：
通过the user manual for RN4020去，你可以看到，该芯片具有默认的电池服务和型号，软件版本等一些特点，但没有默认Rx和Tx的特性。
在这种情况下，您在代码中找到的特征仅仅是设备信息，实际上是无用的。你必须首先在芯片上定义你自己的私人服务和特性。请参阅manual中的示例3-1。一旦您使用唯一的UUID定义私有服务和特性，您可以将数据写入该数据，并使用相同的UUID在Android上阅读。
+0
我想感谢您的快速回复。但是我有一个问题，如果我使用微芯片的应用程序，我可以读取数据（它是一个终端），如果芯片上没有定义Rx和Tx，那该怎么做？ –
+0
很难说没有看到你的代码。但我猜你可能有一个预定义的特征。尝试使用它，看看它是否工作。无论如何，最好使用特有的UUID在Android中读取它，而不是遍历所有这些。 – SoroushA
+0
你在正确的轨道上。我的建议是代替服务和特性的.get（0），使用gatt.getService（UUID.fromString（SERVICE_UUID））。getCharacteristic（UUID.fromString（CHARACTERISTIC_UUID））; 然后在您的芯片端代码上，将您的数据写入具有该UUID和voila的特性中！ – SoroushA
答
我得到RN4020在processing.org与arduino平台结合使用。如果你仍然有兴趣，让我知道。
您是否将SW唤醒和硬件唤醒引脚连接到vcc 3.3v？ 你不必去开始你的CMD everythime。
我只是将CDM直接连接到VCC。一旦你给重启命令，它直接进入MLDP。
+2
您应该修复语法/拼写错误。这真的会损害你的答案的可读性。 – Laurel
BLE设备发送数据时，无论是通过通知服务。或者您可以阅读该服务，其中大部分数据都是十六进制格式，因此您必须将其转换。所以代码更具体的答案 – AAnkit