利用小米MiBand和BLE测量心率

Question

我试图实现简单的sdk与健身跟踪器小米米带工作。目前，我可以跟踪步骤，驱动振动，处理传感器触摸，但我有一个问题的心率测量。基于https://github.com/pangliang/miband-sdk-android的My。为了测量心率，需要将描述符写入适当的特征，以便在改变该特征的值时处理回调，然后将适当的数据写入心率控制点特征，以直接启动心率测量过程。问题是心率测量过程在数据启动后还没有启动，这一过程是成功地写入了的特征(当米波段开始测量心率时，底层传感器闪烁绿色)。这可能是由健身跟踪器的新固件(固件版本: 4.15.12.10；HeartRate版本: 1.3.74.64)造成的，或者我的代码中有一些缺陷：

/-------- MiBandProfile --------/
public static final UUID UUID_SERVICE_HEARTRATE = UUID.fromString("0000180d-0000-1000-8000-00805f9b34fb");
public static final UUID UUID_NOTIFICATION_HEARTRATE = UUID.fromString("00002a37-0000-1000-8000-00805f9b34fb");
public static final UUID UUID_CHAR_HEARTRATE = UUID.fromString("00002a39-0000-1000-8000-00805f9b34fb");
public static final UUID UUID_DESCRIPTOR_UPDATE_NOTIFICATION = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb");

/-------- MiBandProtocol --------/
public static final byte[] START_HEART_RATE_SCAN = {21, 1, 1};

/-------- BleProvider --------/
public class BleProvider extends BluetoothGattCallback {

public interface NotifyListener {
     void onNotify(byte[] data);
}

private HashMap<UUID, NotifyListener> mNotifyListeners = new HashMap<UUID, NotifyListener>();
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.
.
public void setNotifyListener(UUID serviceUUID, UUID charaUUID, NotifyListener listener) {
        //enable chara notofication
        if (this.mGatt == null || !this.mIsServicesDiscovered) {
            if (DBG) Log.d(Debug.TAG, "Device is not connected or services are not discovered");
            return;
        }

        BluetoothGattCharacteristic chara = this.mGatt.getService(serviceUUID).getCharacteristic(charaUUID);

        if (DBG) Log.d(Debug.TAG, "setCharacteristicNotification: " + this.mGatt.setCharacteristicNotification(chara, true));
        BluetoothGattDescriptor descriptor = chara.getDescriptor(MiBandProfile.UUID_DESCRIPTOR_UPDATE_NOTIFICATION);
        if (DBG) Log.d(Debug.TAG, "setValue: " + descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE));
        if (DBG) Log.d(Debug.TAG, "writeDescriptor: " + this.mGatt.writeDescriptor(descriptor));
        this.mNotifyListeners.put(charaUUID, listener);
}

@Override
public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
        //this method must be called when the characteristic value was changed but nothing happened :(
        super.onCharacteristicChanged(gatt, characteristic);

        if (this.mNotifyListeners.containsKey(characteristic.getUuid())) {
            this.mNotifyListeners.get(characteristic.getUuid()).onNotify(characteristic.getValue());
        }
}
} //end BleProvider

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setNotifyListener(MiBandProfile.UUID_SERVICE_HEARTRATE, MiBandProfile.UUID_NOTIFICATION_HEARTRATE, new BleProvider.NotifyListener(){...});
//waiting few seconds
writeCharacteristic(MiBandProfile.UUID_SERVICE_HEARTRATE, MiBandProfile.UUID_CHAR_HEARTRATE, MiBandProtocol.START_HEART_RATE_SCAN);

也许这个协议被废弃了，有些人可以和我分享一个新的协议。我会很高兴的)谢谢。

Answer 1

我解决了问题！在调用setNotifyListener跟踪脉冲值的变化之前，必须将用户信息(年龄、体重)写到适当的特性上，因为没有这个Mi波段就无法开始测量。