NINA-B31 series - Getting Started
UBX-18022394 - R02
Introduction
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1.3
u-blox Low Energy Serial Port Service (SPS)
In Bluetooth BR/EDR, there is a Serial Port Profile (SPP) that emulates a serial port over the air. For
Bluetooth low energy, there is no such profile and thereby no standardized way of transferring generic
data over the air.
The u-blox Low Energy Serial Port Service is a non-standard profile developed for the u-blox serial port
adapter concept. The specification is open and may be implemented in any Bluetooth Low Energy
device to enable generic data transmission.
The serial port service is implemented on top of the Generic Attribute Profile (GATT). It contains the
following characteristics:
•
FIFO for reading and writing data
•
Credits to simulate the Bluetooth BR/EDR credit-based flow control
To connect, the central/client side sets up the ACL (Asynchronous Connection-Less) link and enables
indications for both the FIFO and credits characteristics. Then the server side sends the number of
credits to the client using the credit indication, and the client writes the number of credits to the
server. The credits correspond to the number of packets the remote side may write before receiving
new credits. The received credits are added to the remaining ones (if any).
When the connection has been established and credits have been received, data transmission starts.
The client writes to the FIFO and the server sends indications or notifications with the FIFO data.
Connections without credits are also supported. Connections without credits are faster to establish
and ideal for scenarios where a small amount of data shall be transferred.
For more information, see the u-blox Low Energy Serial Port Service Protocol Specification [10].
1.4
NFC
The NINA-B31 series includes NFC (Near Field Communication), which can be used to “touch”
NINA-B31 to an NFC reader device to perform actions. NFC can simplify the connection process to a
module and reduce the number of steps when provisioning an NINA-B31 module. NFC can also be used
to launch apps on smartphones and store a web link or a text.
An NFC antenna is included in the NINA-B31 evaluation kit.
