Integration Manual

ANNA-B4 series - System integration manual
UBX-21000517 - R03 Contents Page 17 of 76
C1-Public
For more information about the UART interface characteristics, see also the ANNA-B402 and
ANNA-B412 data sheet [5] and [6].
Interface
Default configuration
COM port
115200 baud, 8 data bits, no parity, 1 stop bit, hardware flow control
Table 10: Default settings for the COM port while using the u-connectXpress software
It is advisable to make the UART available as either test points or as available through a connected
header for software upgrade.
The IO level of the UART follows the VCC voltage and can subsequently in the range of 1.8–3.6 V. If you
are connecting the ANNA-B4 module to a host with a different voltage on the UART interface, a level
shifter should be used.
Serial peripheral interface (SPI)
The ANNA-B4 series supports up to four serial peripheral interfaces that can operate in both master
and slave modes with a maximum serial clock frequency of 8 MHz in both these modes.
The SPI interfaces use the four following signals:
• SCLK
• MOSI
• MISO
• CS
When using the SPI interface in master mode, it is possible to use GPIOs as additional Chip Select (CS)
signals to allow addressing of multiple slaves.
I2C interface (open CPU only)
The Inter-Integrated Circuit (I2C) interfaces can be used to transfer or receive data on a 2-wire bus
network. The ANNA-B4 series contains up to two I2C bus interfaces and can operate as both master
and slave using both standard (100 kbps) and fast (400 kbps) transmission speeds. The interface
uses the SCL signal to clock instructions and data on the SDL signal.
External pull up resistors are required for the I2C interface. The value of the pull-up resistor should be
selected depending on the speed and capacitance of the bus.
2.7 GPIO pins
ANNA-B4 series modules can provide up to 33 pins, which can be configured as general-purpose input
or output. Eight GPIO pins are capable of handling analog functionality. All pins are capable of handling
interrupt.
Function
Description
Default ANNA-B4 pin
Configurable GPIOs
General purpose input
Digital input with configurable edge detection and
interrupt generation.
Any
General purpose
output
Digital output with configurable drive strength, pull-
up, pull-down, open-source, open-drain and/or slew
rate.
Any
Pin disabled
Pin is disconnected from input buffers and output
drivers.
All*
Any
Timer/ counter
High precision time measurement between two
pulses/ Pulse counting with interrupt/event
generation.
Any
Interrupt/ Event
trigger
Interrupt/event trigger to the software application/
Wake up event.
Any