Dear community,
I would like to know how to send as much data as possilbe from a Nexus 4 to an NRF51822 based device. For that I think I need to send multiple packets per connection interval.
What I did:
I searched the interwebs and also this community. ;) and found this: devzone.nordicsemi.com/.../
I set the connection interval to:
In the Sniffer I see that the devices agree to about 10 ms which is fine:
To send Data I use a queue and the onCharacteristicsWrite callback to pump data in 20 byte chunks to the device:
public void writeCharacteristicBulk()
{
BluetoothGattService service = mBluetoothGatt.getService(UUID.fromString("xxx"));
BluetoothGattCharacteristic bluetoothGattCharacteristicA = service.getCharacteristic(UUID.fromString("xxx"));
byte[] value;
boolean status;
bluetoothGattCharacteristicA.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
value = mDataToTransfer.poll();
if(value!=null) {
bluetoothGattCharacteristicA.setValue(value);
status = mBluetoothGatt.writeCharacteristic(bluetoothGattCharacteristicA);
Log.d(TAG, "write " + bluetoothGattCharacteristicA.getUuid() + " status " + status);
}
}
and later ...
@Override
public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
writeCharacteristicBulk();
}
But when I send large amounts of data (96 packets of 20 byte) I only see one per interval in the sniffer:
So the question is: Is it possible to send more than that? Or is the throughput calculation of the above mentioned question only valid for android receiving data?
Thanks and have a great weekend Matthias
