Android how to read multiple BLE characteristics with a PriorityQueue
A bit stuck here, might need your help. I want to read several BLE characteristics at once, some people suggest using PriorityQueue for that. I already know all the uuids, etc. just need a way to read several at once. Could anyone explain how exactly should it look like? Or maybe there is yet another easier solution?
Thanks in advance, here is my code:
public static final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
PriorityQueue<BluetoothGattCharacteristic> queue = new PriorityQueue<BluetoothGattCharacteristic>();
// When connection state changes
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
if (newState == BluetoothProfile.STATE_CONNECTED) {
Log.v(TAG, "Connected!");
gatt.discoverServices();
}
if (newState == BluetoothProfile.STATE_DISCONNECTED) {
Log.v(TAG, "Disconnected...");
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
List<BluetoothGattService> services = gatt.getServices();
BluetoothGattService rightService = null;
for (int i = 0; i < services.size(); i++) {
if (services.get(i).getCharacteristics().size() > 8) {
rightService = services.get(i);
}
}
List<UUID> uuidsList;
UUID TRANSMISSION_POWER = rightService.getCharacteristics().get(4).getUuid();
UUID BROADCASTING_INTERVAL = rightService.getCharacteristics().get(6).getUuid();
UUID BEACON_NAME = rightService.getCharacteristics().get(8).getUuid();
UUID CONNECTION_MODE = rightService.getCharacteristics().get(9).getUuid();
//UUID SOFT_REBOOT = rightService.getCharacteristics().get(10).getUuid();
uuidsList = new ArrayList<UUID>();
uuidsList.add(TRANSMISSION_POWER);
uuidsList.add(BROADCASTING_INTERVAL);
uuidsList.add(BEACON_NAME);
uuidsList.add(CONNECTION_MODE);
//uuidsList.add(SOFT_REBOOT);
queue.add(rightService.getCharacteristic(uuidsList.get(0)));
queue.add(rightService.getCharacteristic(uuidsList.get(1)));
queue.add(rightService.getCharacteristic(uuidsList.get(2)));
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
Log.v(TAG, "CHARACTERISTIC VALUE___: " + characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, 0));
onServicesDiscovered(gatt, 0);
}
};
UPDATE:
even after putting them on different threads it still only reacts to one gatt.readCharacteristic(...). like following:
// Gatt Callback
public static final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
// When connection state changes
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
if (newState == BluetoothProfile.STATE_CONNECTED) {
Log.v(TAG, "Connected!");
gatt.discoverServices();
}
if (newState == BluetoothProfile.STATE_DISCONNECTED) {
Log.v(TAG, "Disconnected...");
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
List<BluetoothGattService> services = gatt.getServices();
/*
DISPLAY ALL SERVICES AND CHARACTERISTICS
for (int i = 0; i < services.size(); i++) {
Log.v(TAG, "SERVICE____: " + services.get(i).getUuid());
for (int k = 0; k < services.get(i).getCharacteristics().size(); k++) {
Log.v(TAG, "CHARACTERISTIC____: " + services.get(i).getCharacteristics().get(k).getUuid());
}
}
*/
BluetoothGattService rightService = null;
for (int i = 0; i < services.size(); i++) {
if (services.get(i).getCharacteristics().size() > 8) {
rightService = services.get(i);
}
}
List<UUID> uuidsList;
UUID TRANSMISSION_POWER = rightService.getCharacteristics().get(4).getUuid();
UUID BROADCASTING_INTERVAL = rightService.getCharacteristics().get(6).getUuid();
UUID BEACON_NAME = rightService.getCharacteristics().get(8).getUuid();
UUID CONNECTION_MODE = rightService.getCharacteristics().get(9).getUuid();
//UUID SOFT_REBOOT = rightService.getCharacteristics().get(10).getUuid();
uuidsList = new ArrayList<UUID>();
uuidsList.add(TRANSMISSION_POWER);
uuidsList.add(BROADCASTING_INTERVAL);
uuidsList.add(BEACON_NAME);
uuidsList.add(CONNECTION_MODE);
//uuidsList.add(SOFT_REBOOT);
class powerThread extends Thread{
UUID uuid;
BluetoothGatt gatt;
BluetoothGattService service;
public powerThread(UUID uuid, BluetoothGatt gatt, BluetoothGattService service) {
this.gatt = gatt;
this.service = service;
this.uuid = uuid;
}
@Override
public void run() {
gatt.readCharacteristic(service.getCharacteristic(uuid));
}
}
powerThread pt = new powerThread(TRANSMISSION_POWER, gatt, rightService);
pt.run();
class intervalThread extends Thread{
UUID uuid;
BluetoothGatt gatt;
BluetoothGattService service;
public intervalThread(UUID uuid, BluetoothGatt gatt, BluetoothGattService service) {
this.gatt = gatt;
this.service = service;
this.uuid = uuid;
}
@Override
public void run() {
gatt.readCharacteristic(service.getCharacteristic(uuid));
}
}
intervalThread it = new intervalThread(BROADCASTING_INTERVAL, gatt, rightService);
it.run();
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
Log.v(TAG, "CHARACTERISTIC VALUE___: " + characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, 0));
}
};
Answer
To anyone who might encounter the same problem, here is an easy solution using a List<> of characteristics.
public static final BluetoothGattCallback readGattCallback = new BluetoothGattCallback() {
List<BluetoothGattCharacteristic> chars = new ArrayList<>();
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
if (newState == BluetoothProfile.STATE_CONNECTED) {
Log.v(TAG, "Connected!");
broadcastingInterval = 999;
transmissionPower = 999;
gatt.discoverServices();
}
if (newState == BluetoothProfile.STATE_DISCONNECTED) {
Log.v(TAG, "Disconnected...");
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
List<BluetoothGattService> services = gatt.getServices();
BluetoothGattService rightService = null;
for (int i = 0; i < services.size(); i++) {
if (services.get(i).getCharacteristics().size() > 8) {
rightService = services.get(i);
}
}
chars.add(rightService.getCharacteristics().get(4));
chars.add(rightService.getCharacteristics().get(6));
requestCharacteristics(gatt);
}
public void requestCharacteristics(BluetoothGatt gatt) {
gatt.readCharacteristic(chars.get(chars.size()-1));
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
if (characteristic.getUuid().toString().substring(7, 8).equals("5")) {
transmissionPower = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, 0);
Log.v(TAG, "tPOWER READ");
} else if (characteristic.getUuid().toString().substring(7,8).equals("7")) {
broadcastingInterval = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, 0);
Log.v(TAG, "INTERVAL READ");
}
chars.remove(chars.get(chars.size() - 1));
if (chars.size() > 0) {
requestCharacteristics(gatt);
} else {
gatt.disconnect();
}
}
}
};
- Create a list of characteristics
- In onServicesDiscovered populate the list with characteristics you want to read/write
- Create a new method called requestCharacteristics(gatt) and pass the gatt object to it. Call this method from onServicesDiscovered after adding characteristics to the list.
- In requestCharacteristics() method call gatt.readCharacteristic(chars.get(chars.size()-1));
- In onCharacteristicRead check if size of your list is not zero, then read your characteristic, remove the last item of your list and call requestCharacteristic() again.
- That's all