Hi all,
I am trying to get an Android Nexus 5X app to work with an NRF chip, and facing some problems, specifically with writing to a characteristic. Really hope to get some help.
Specifically, I am trying to set a real-time clock (RTC) on the nrf by means of the app. Details given to me about the GATT service characeristic are as follows:
Properties: Read - Mandatory, Write - Mandatory, WriteWithoutResponse - Excluded, SignedWrite - Excluded, Notify - Excluded, Indicate - Excluded, Writeable Auxilliaries - Excluded, Broadcast - Excluded.
Security: ENC_NO_MITM
Descriptors: None
After connecting to the nrf, my implementation of 'onServiceDiscovered()' is as follows.
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
// Get the characteristic
BluetoothGattCharacteristic loggingRTCCharacteristic = gatt.getService(loggingServiceUUID).getCharacteristic(loggingRTCControlPointCharacteristicUUID);
// Read characteristic (which succeeded, as onReadCharacteristic is invoked)
boolean successFlag = gatt.readCharacteristic(loggingRTCCharacteristic);
// Check for success.
// Set a plausible timestamp.
int year_lsb = 221; int year_msb = 7;
int month = 3;
int dayOfMonth = 4;
int dayOfWeek = 7;
int hour = 9;
int min = 3;
int sec = 15;
byte[] timeStamp = {(byte)year_lsb, (byte)year_msb, (byte)month, (byte)dayOfMonth, (byte)dayOfWeek, (byte)hour, (byte)min, (byte)sec};
logingRTCCharacteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT);
// This returns a failure. The onCharacteristicWrite() function is not invoked either.
successFlag = gatt.writeCharacteristic(loggingRTCCharacteristic); }
The readcharacteristic() is successful, while writecharacteristic() failed. I have tried to change the write type of the other 2 options: WRITE_TYPE_ENCRYPTED, and WRITE_TYPE_NO_RESPONSE, but no joy. Can anyone please advise, as I cannot seem to find anything that helps online. Thanks!
