Data Sheet
NINA-B41-data sheet
2.5.1GPIO
NINA-B41 series modules have a versatile pin-out. In an un-configured state, the modules support
a total of 26 GPIO pins with no analog interfaces. All interfaces or functions must be allocated to a
GPIO pin before use.
2.5.2Universal Asynchronous Receiver/Transmitter (UART)
There are two UART interfaces that may be used on NINA-B41; a primary and a secondary interface.
Note For more information about how the interfaces are controlled using AT commands, see
the u-connectXpress AT commands manual and u-connectXpress software user guide.
These 4-wire UART interfaces support hardware flow control and baud rates up to 1 Mbps. Other
characteristics of the UART interface are listed below:
• Default baud rate is 115200 and frame configuration is 8N1, meaning eight (8) data bits, no (N)
parity bit, and one (1) stop bit.
•
Frames are transmitted in such a way that the least significant bit (LSB) is transmitted first.
• Pin configuration:
• TXD, data output pin
• RXD, data input pin
• RTS, Request To Send, flow control output pin (optional)
• CTS, Clear To Send, flow control input pin (optional)
• Hardware flow control or no flow control is supported.
• Power saving indication available on the hardware flow control output (RTS pin): The line is
driven to the OFF state when the module is not ready to accept data signals.
• Programmable baud rate generator allows most industry standard rates, as well as non-
standard rates up to 1 Mbps.
2.5.2.1Primary UART
The primary interface is used for communication with NINA-B41 from a host controller. It is used to
configure NINA-B41 and to transmit or receive data to or from a Bluettooth LE link or any sensors
that are connected. The primary interface has a fixed pin configuration that may not be changed.
In addition to the normal RXD, TXD, CTS, and RTS signals, the u-connectXpress software adds the
DSR and DTR pins to the UART interface. Note that they are not used as originally intended, but to
control the state of the NINA module.
Depending on the current configuration, the DSR pin can be used to:
• Enter the command mode
• Disconnect and/or toggle connectable status
• Enable/disable the rest of the UART interface
• Enter/wake up from the sleep mode
The DTR pin can be used to indicate:
• The System mode
• If the SPS peers are connected
• A Bluetooth LE GAP connection
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