SARA-N2 / N3 series - System integration manual
UBX-17005143 - R13
Design-in
Page 66 of 95
C1-Public
2.6.3
Additional UART interface
2.6.3.1
Guidelines for additional UART circuit design
The SARA-N2 modules include
GPIO1
pin, operating at
V_INT
voltage level (1.8 V) as additional UART
interface for diagnostic purpose, to collect trace logs.
A suitable application circuit can be the one illustrated in
, where direct external access is
provided for diagnostic purpose by means of Test-Points made available on the application board for
GPIO1
and
V_INT
lines.
SARA-N2 series
16
GPIO1
GND
TestPoint
4
V_INT
TestPoint
Figure 44: SARA-
N2 modules’ additional
UART application circuit providing access for diagnostic purpose
☞
It is recommended to provide a direct access to the
GPIO1
pin of SARA-N2 module by means of
accessible Test-Point for diagnostic purpose.
The SARA-N3 series modules include the
RXD_FT
and
TXD_FT
pins, operating at the
V_INT
voltage
level (1.8 V or 2.8 V, according to
VSEL
input pin external configuration: see
) as additional UART
interface for Firmware update and diagnostic Trace logs collection.
A suitable application circuit can be similar to the one illustrated in
, where direct external
access is provided for Firmware update and diagnostic purpose by means of test-points made
available on the application board for
RXD_FT
,
TXD_FT
and
V_INT
lines.
SARA-N3 series
29
TXD_FT
GND
TestPoint
4
V_INT
TestPoint
28
RXD_FT
TestPoint
Figure 45: SARA-
N3 modules’ additional UART application circuit providing access for FW update and diagnostic purpose
☞
It is recommended to provide a direct access to the
RXD_FT
and
TXD_FT
pins of SARA-N3 module
by means of accessible Test-Points for diagnostic purpose.
2.6.3.2
Guidelines for additional UART layout design
There are no specific layout design recommendations for additional UART.
2.6.4
DDC (I2C) interface
☞
The DDC (I2C) interface is not supported by the "02" product version of the SARA-N2 series
modules: the
SDA
and
SCL
lines can be left unconnected.
☞
The DDC (I2C) interface is not supported by the "00" product version of the SARA-N3 series
modules: the
SDA
and
SCL
lines can be left unconnected.