NEO-D9C - Integration manual
Pin no.
Name
I/O
Description
12
GND
I
Ground
13
GND
I
Ground
14
ANT_OFF
O
External LNA disable - default active high
15
ANT_DETECT
I
Active antenna detect - default active high
16
ANT_SHORT_N
O
Active antenna short detect- default active low
17
EXTINT
I
External interrupt pin
18
SDA / SPI CS_N
I/O
I2C data if D_SEL = VCC (or open); SPI chip select if D_SEL = GND
19
SCL / SPI SLK
I/O
I2C clock if D_SEL = VCC (or open); SPI clock if D_SEL = GND
20
TXD / SPI MISO
O
UART1 output if D_SEL = VCC (or open); SPI MISO if D_SEL = GND
21
RXD / SPI MOSI
I
UART1 input if D_SEL = VCC (or open); SPI MOSI if D_SEL = GND
22
Reserved
-
No connection
23
VCC
I
Supply voltage
24
GND
I
Ground
Table 5: NEO-D9C pin assignment
4.2 Antenna
An active antenna NEO-D9C is mandatory for operation.
The NEO-D9C needs to receive L2 and L6 signals in order to operate. A combined L1/L2/L6 active
antenna is recommended if used with a ZED-F9x.
If a combined L1/L2/L6 active antenna needs to be implemented in an application case, it is
recommended that an OEM active antenna module is used that meets our specification. It is
not a simple task to implement the required RF circuitry. Sourcing the required components to
meet the RTK group delay specification is not a simple process compared to previous L1 only
implementations.
A suitable ground plane is required for the antenna to achieve good performance if a
combined L1/L2/L6 antenna is used.
Location of the antenna is critical for reaching good performance. Even more so if a
combined L1/L2/L6 for RTK is used. The application requirements make it unsuitable for
under vehicle dash location or rear view mirror location, etc.
Figure 18: NEO-D9C required signals
UBX-21031631 - R02
4 Design
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