I'm currently developing a long term data logger device based on an RFduino/RTC/PressureSensor.
I already completed the logging functions for writing to SD card.
Now, i want to enable the device to transfer the logfile to a (Android) smartphone.
Sending Data via RFduinoBLE.send is already working.
What i want to do now, is making a reliable transfer service.
The Rfduino should send the data in packets, along with a number to identify the packet.
The Phone sould answer with an ACK to request the next packet or NACK to request resending the current packet.
I got that handshake already working, simulated over Serial Monitor.
What i need to know is:
How does the send function form the transmitted GATT packages?
How many Bytes can it transfer in one GATT Package?
Is it possible to custom make the Package? (for setting up a proper Package format)