SARA-G450 - System integration manual
UBX-18046432 - R08
System description
Page 29 of 143
C1-Public
1.9
Serial interfaces
SARA-G450 modules provide the following serial communication interfaces:
UART interface: 9-wire unbalanced 1.8 V / 3 V asynchronous serial interface supporting (see
o
AT command mode
4
o
Data mode and online command mode
o
MUX functionality, including dedicated GNSS tunneling
5
o
FW upgrades by means of the FOAT feature
Secondary auxiliary UART interface
6
: 3-wire unbalanced 1.8 V / 3 V asynchronous serial interface
supporting (see
):
o
AT command mode
o
Data mode and online command mode
o
GNSS tunneling
Additional UART interface for FW upgrade and tracing: 3-wire unbalanced 1.8 V / 3 V asynchronous
serial interface supporting (see
):
o
FW upgrades by means of the dedicated tool
o
Trace log capture (diagnostic purpose)
DDC interface
7
: I2C-bus compatible 1.8 V / 3 V interface supporting (see
):
o
Communication with u-blox GNSS positioning chips / modules
☞
Secondary auxiliary UART interface is not supported by the “00” product version. This interface
should be left unconnected and should not be driven by external devices.
☞
DDC (I2C) interface is not supported by the “00” product version. This interface should be left
unconnected and should not be driven by external devices.
1.9.1
Primary main serial interface (UART)
1.9.1.1
UART features
The UART interface is a 9-wire unbalanced asynchronous serial interface, supporting:
AT command mode
Data mode and Online command mode
Multiplexer protocol functionality (see
FW upgrades by means of the FOAT feature (see
The main characteristics of the interface are the following:
Complete serial port with RS-232 functionality conforming to ITU-T V.24 recommendation
with CMOS compatible signal levels: 0 V for low data bit or ON state and 1.8 V / 3 V for high data
bit or OFF state (for detailed electrical characteristics, see the SARA-G450 data sheet
Data lines (RXD as output, TXD as input)
Hardware flow control lines (CTS as output, RTS as input)
Modem status and control lines (DTR as input, DSR as output, RI as output, DCD as output)
4
See the u-blox AT commands manual
for the definition of the command mode, data mode, and online command mode.
5
SARA-G450 modules product version “00” do not support GNSS tunneling.
6
SARA-G450 modules product version “00” do not support secondary auxiliary UART.
7
SARA-G450 modules product version “00” do not support DDC I
2
C-bus compatible interface.
