Android设备作为BLE中央和读/写操作，无需外围设备触发

Question

My Android app is made as a BLE central device. I have a device which is peripheral. I want to send some data from Android app to peripheral device without any request from the peripheral. Can I achieve this ?

In my peripheral device to write data i am using below code :

BluetoothGattCharacteristic charac = Service
            .getCharacteristic(UUID.fromString(SampleGattAttributes.LOCAL_TIME));
byte[] value = new byte[1];
    String valuetosend = "data from client to server";
    value = valuetosend.getBytes();
    charac.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
    charac.setValue(value);


    Log.d("BluetoothLeservice::","Write Status:" + charac.getValue());
    boolean status = mBluetoothGatt.writeCharacteristic(charac);

Do I have to do in the same way for central also? Any reference links would be helpful.

Answer 1

I think the process is same, you have to write data to the particular characteristic and service. You should know the value of the characteristic and service. In your case it is SampleGattAttributes.LOCAL_TIME .