UNICORECOMM UM482 User manual

WWW.UNICORECOMM.COM
INSTALLATION AND OPERATION
USER MANUAL
Data subject to change without notice.
Communications, Inc. Copyright© 2009-2021, Unicore
All-constellation Multi-frequency
GPS/BDS/GLONASS/Galileo
U M482
High Precision Positioning and
Heading Module

i
Revision History
Version
Revision History
Date
Ver. 1.0
First release
Aug. 2017
R3.1
Revise the description of RST_N configuration and the
action execution time
Add the related description to clarify the VCC restrictions
2019-08-26
R3.2
Chapter 2.1: delete the legacy parameter and add pin
mechanical spec
Chapter 2.2: add the working current info of No.17 pin
2019-10-14
R3.3
1.2 Technical Specifications: update the weight value
from 8.8 to 9.2
1 Overview: update the product diagram
2020-02-26
R3.4
1.2 Technical Specifications: add QZSS
2020-07-01
R3.5
Update BDS frequencies in section 1.2
2020-10-21
R3.6
Add external antenna feed reference design
2020-12-17
R4
Remove information on the MEMS device and add RF
input power consumption of the antenna
2021-04-13
R4.1
Modify pin definition in Figure 2-2
2021-06-30
R4.2
Modify Figure 3-4, fix typo and correct inaccurate
expressions in chapter 5.2 and 5.3
2021-07-06
Disclaimer
Information in this document is subject to change without notice and does not
represent a commitment on the part of Unicore Communications, Inc. No part of this
manual may be reproduced or transmitted in any form or by any means, electronic
or mechanical, including photocopying and recording, for any purpose without the
express written permission of a duly authorized representative of Unicore
Communications, Inc. The information contained within this manual is believed to be
true and correct at the time of publication.
© Copyright 2009-2021 Unicore Communications, Inc. All rights RSV.

UM482 User Manual
ii
Foreword
This <User Manual> offers you information on the features of the hardware, the
installation, specifications and use of the UNICORECOMM UM482 product.
For the generic version of this manual, please refer to the appropriate part of this manual
depending on your purchased product configuration - concerning CORS, RTK and Heading.
Readers it applies to
This <User Manual> is written for technologists who have knowledge of GNSS
Receivers to some extent –it is not for general readers.

i
Contents
1OVERVIEW .............................................1
1.1 KEY FEATURES ..............................................................................................................................1
1.2 TECHNICAL SPECIFICATIONS.............................................................................................................2
1.3 INTERFACES..................................................................................................................................3
2HARDWARE .............................................4
2.1 DIMENSIONS................................................................................................................................4
2.2 PIN DEFINITION (TOP VIEW)...........................................................................................................5
2.3 PIN FUNCTION .............................................................................................................................5
2.4 ELECTRICAL SPECIFICATIONS ............................................................................................................8
2.5 OPERATIONAL CONDITIONS.............................................................................................................8
2.6 PHYSICAL SPECIFICATIONS...............................................................................................................9
3HARDWARE DESIGN ......................................9
3.1 DESIGN IN CONSIDERATIONS ...........................................................................................................9
3.2 UM482 REFERENCE DESIGN ........................................................................................................10
3.3 PINS.........................................................................................................................................11
3.4 PCB PACKAGING ........................................................................................................................13
3.5 RESET SIGNAL ............................................................................................................................13
3.6 EXTERNAL ANTENNA FEED DESIGN.................................................................................................14
4INSTALLATION AND CONFIGURATION .......................15
4.1 ESD HANDLING PRECAUTIONS ......................................................................................................15
4.2 HARDWARE INSTALLATION ............................................................................................................15
4.3 POWER ON................................................................................................................................18
4.4 CONFIGURATION AND OUTPUT ......................................................................................................18
4.5 OPERATION STEPS.......................................................................................................................19
5CONFIGURATION COMMANDS...............................20
5.1 REFERENCE STATION CONFIGURATION.............................................................................................21
5.2 ROVER STATION CONFIGURATION...................................................................................................22
5.3 MOVING BASE CONFIGURATION ....................................................................................................22
5.4 HEADING CONFIGURATION ...........................................................................................................23
5.5 HEADING2 CONFIGURATION .........................................................................................................24
6ANTENNA DETECTION ...................................24
7FIRMWARE UPGRADE ....................................25
8SOLDERING RECOMMENDATION.............................26
9PACKAGING ...........................................27

1
1Overview
UM482 is the smallest, all-constellation, multi-frequency, high precision RTK and
heading module developed by Unicore Communications Inc. The module is targeted
for use in robots, UAVs and intelligent driving applications.
The UM482 provides reliable centimeter-level accuracy and a high accuracy heading
output at high update rates.
By employing a single UC4C0 (432 channel tracking) baseband chip with internal RF
front-end in a single-sided SMD package, UM482 can achieve very small size (30x40
mm). It can simultaneously track GPS L1/L2 + BDS B1I/B2I + GLONASS L1/L2+Galileo
E1/E5b+L1/L2 QZSS.
The UM482 adopts UNICORECOMM’s new-generation “UGypsophila” RTK processing
technology and takes advantage of high-performance data sharing capability and the
extremely simplified operating system within the NebulasII GNSS SoC chip. It uses
optimized multi-dimensional RTK matrix pipeline computation, resulting in much
higher RTK processing capability.
Figure 1-1 UM482 Module
1.1 Key Features
30×40 mm, small footprint multi-frequency RTK and heading module, SMD
package
Supports GPS L1/L2+BDS B1I/B2I +GLONASS L1/ L2+Galileo E1/E5b and QZSS
L1/L2
Precise RTK positioning and heading
RTK Initialization time < 5s
Dual antenna input with supporting antenna signal detection
20Hz data output rate
Adaptive recognition of RTCM input data format

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May also support odometer input and external high-performance IMU
interface*
1.2 Technical Specifications
Table 1-1 Performance Specifications
Channels
432 channels, based on
NebulasII SoC chip
Cold Start
＜25s
Frequency
GPS L1/L2
BDS B1I/B2I1
GLONASS L1/L2
Galileo E1/E5b
QZSS L1/L2
RTK Initialization
Time
＜5s (typical)
Single Point
Positioning (RMS)
Horizontal: 1.5m
Vertical: 2.5m
Initialization
Reliability
＞99.9%
DGPS (RMS)
Horizontal: 0.4m
Vertical: 0.8m
Differential Data
RTCM 3.0/3.2/3.3
Data Formats
NMEA-0183，
Unicore Binary
RTK (RMS)
Horizontal: 1cm+1ppm
Vertical: 1.5cm+1ppm
Update Rate
20Hz
Time accuracy
(RMS)
20ns
Heading Accuracy
(RMS)
0.2 degree/1m baseline
Data Accuracy
(RMS)
0.03m/s
Size
30×40×4 mm
Power Consumption
2.4W (Typical)
Weight
9.2g
Table 1-2 Functional Ports
3x UART, 1xI2C, 1x SPI (LV-TTL)
1x1PPS (LV-TTL)
1x Event input
1
BDS B1I/B3I is supported with the firmware upgraded

3
1.3 Interfaces
RF In
RF
Chip
SAW
Filter
NebulasII UART
SPI
GPS
BDS
GLO
GAL
QZSS
SBAS
Interface Event
TCXO
RF In SAW
Filter
I2C
ANT1_PWR
ANT2_PWR
PPS
Figure 1-2 Block Diagram
RF Part
GNSS signals received from the antenna via a coaxial cable are filtered and enhanced.
The RF part convert the RF input signals into the IF signal, and then IF analog signals
are converted into the digital signals required for NebulasII digital processing.
NebulasII SoC (UC4C0)
The UM482 incorporates the processing from the NebulasII (UC4C0),
UNICORECOMM’s new generation high precision GNSS SoC using 55nm low power
design. It supports up to 12 digital intermediate frequencies or 8 analog intermediate
frequency signals, and can track 12 navigation signals with 432 channels.
1PPS
UM482 outputs a 1 Pulse-per-second time strobe with a corresponding time and
positioning tag. The pulse width/polarity is configurable.
Event
UM482 provides a 1 Event Mark Input with adjustable pulse width and polarity.
Reset (RST_N)/Factory Default (FRESET_N)
The reset signal RST_N should be set active low for no less than 20ms effective time.

UM482 User Manual
4
When the FRESET_N is activated, the user parameters in NVM will be cleared and the
module is restored to factory default settings. The FRESET_N is active low. Please pull
FRESET_N pin to low for more than 5s to ensure a successful reset.
2Hardware
2.1 Dimensions
Table 2-1 Dimensions
Symbol
Value (mm)
Tolerance (mm)
A
40.00
-0.2 +0.5
B
30.00
±0.2
C
4.00
±0.2
D
1.58
±0.1
E
1.27
±0.1
K
0.91
±0.1
M
1.35
±0.1
N
0.66
±0.1
Figure 2-1 UM482 Mechanical Diagram

5
2.2 Pin Definition (Top View)
The UM482 has 2x30 pins, shown below.
Figure 2-2 UM482 Pin Diagram
2.3 Pin Function
Table 2-2 Pin Descriptions
No
Pin
I/O
Description
1
GND
-
Ground
2
ANT1_IN
I
GNSS antenna signal input (primary antenna)
3
GND
-
Ground

UM482 User Manual
6
No
Pin
I/O
Description
4
GND
-
Ground
5
ANT1_PWR
I
GNSS antenna power supply (for separate heading
antennae)
6
GND
-
Ground
7
ANT_NLOD
O
Primary GNSS antenna open circuit indicator
1: normal
0: antenna is open circuit
8
ANT_FFLG
O
Primary GNSS antenna short circuit indicator
1: normal
0: antenna is short circuit
9
GND
-
Ground
10
RSV
-
RSV
11
RSV
-
RSV
12
RSV
-
RSV
13
RSV
-
RSV
14
GND
-
Ground
15
SPEED
I
odometer- pulse (reserved)
16
FWR
I
odometer- direction (reserved)
17
V_BACKUP
I
When the main power supply of the module VCC is
cut off, V_BCKP enables a separate power supply if
provisioned to RTC and SRAM. Level requirements:
2.0~ 3.6 V, and the working current is about 10uA.
Leave it open without using the hot start function
18
GND
-
Ground
19
PVT STAT
O
PVT positioning indicator, active-high. The module
outputs high level when positioning is available and
outputs low level when no positioning is proceeded.
20
GPIO2
I/O
General IO
21
RSV
-
RSV
22
FRESET_N
I
Reset to factory default (clear all user settings),
LVTTL active-low, activate for longer than 5 seconds
23
ERR_STAT
O
Abnormal indicator, active-high. When the module
self-diagnosis system fails, it outputs high level.
Following completion of successful self-test ERR-STAT
outputs low level
24
RTK_STAT
O
RTK positioning indicator, active-high. When the RTK
solution is fixed, it outputs high level, alternatively it
outputs low level when in other positioning states or
no positioning is proceeded.
25
GND
-
Ground

7
No
Pin
I/O
Description
26
SPI_MISO
I
SPI data master input slave output
27
SPI_MOSI
O
SPI data master output slave input
28
SPI_CLK
O
SPI clock
29
SPI_SS0
O
SPI chip select 0
30
SPI_SS1
O
SPI chip select 1
31
3.3V_VCC
Power
Power Supply (+3.3V)
32
3.3V_VCC
Power
Power Supply (+3.3V)
33
GND
-
Ground
34
GND
-
Ground
35
TXD1
I/O
COM 1 transmit
36
RXD1
I
COM 1 receive
37
TXD2
O
COM 2 transmit
38
RXD2
I
COM 2 receive
39
TXD3
O
COM 3 transmit
40
RXD3
I
COM 3 receive
41
I2C_SDA
I/O
I2C data
42
I2C_SCL
I/O
I2C clock
43
GND
-
Ground
44
PPS
O
1 Pulse per second
45
EVENT
I
Event Mark
46
RST_N
I
Fast reset, will not clear user configurations. Active
Low
47
GND
-
Ground
48
RSV
-
RSV
49
RSV
-
RSV
50
RSV
-
RSV
51
RSV
-
RSV
52
GND
-
Ground
53
ANT2_FFLG
O
Secondary GNSS antenna short circuit indicator
1: normal
0: antenna is short circuit
54
ANT2_NLOD
O
Secondary GNSS antenna open circuit indicator
1: normal
0: antenna is open circuit
55
GND
-
Ground
56
ANT2_PWR
I
Secondary GNSS antenna power supply
57
GND
-
Ground
58
GND
-
Ground
59
ANT2_IN
I
Secondary GNSS antenna signal (for Heading antenna)
60
GND
-
Ground

UM482 User Manual
8
2.4 Electrical Specifications
Table 2-3 Absolute Maximum Ratings
Item
Pin
Min
Max
Unit
Power Supply (VCC)
Vcc
-0.3
3.6
V
Voltage Input
Vin
-0.3
VCC+0.2
V
Primary GNSS Antenna Power
Supply
ANT1_PWR
-0.3
6
V
Primary GNSS Antenna Signal Input
ANT1_IN
-0.3
ANT1_PWR
V
Secondary GNSS Antenna Power
Supply
ANT2_PWR
-0.3
6
V
Secondary GNSS Antenna Signal
Input
ANT2_IN
-0.3
ANT2_PWR
V
RF Input Power Consumption of
Primary antenna
ANT1_IN input power
+15
dBm
RF Input Power Consumption of
Secondary antenna
ANT2_IN input power
+15
dBm
VCC Ripple (Rated Max.)
Vrpp
0
50
mV
Voltage Input (pins other than
RXD1, RXD2, RXD3)
Vin
-0.3
3.6
V
Maximum ESD stress
VESD(HBM)
±2000
V
2.5 Operational Conditions
Table 2-4 Operational Conditions
Item
Pin
Min
Typical
Max
Unit
Condition
Power Supply (VCC)
Vcc
3.2
3.3
3.6
V
Inrush current* (impulse
current during power up)
Iccp
8.8
A
Vcc = 3.3 V
LOW Level Input Voltage
Vin_low_1
-0.3
VCC*
0.3
V
High Level Input Voltage
Vin_high_1
VCC*
0.7
VCC+
0.3
V
LOW Level Output Voltage
Vout_low
0
0.45
V
Iout= 4 mA
High Level Output Voltage
Vout_high
VCC-
0.45
VCC
V
Iout =4 mA
Antenna Gain
Gant
20
30
36
dB
Noise Figure
Nftot
2.5
3
3.5
dB
Primary GNSS Antenna
Power Supply
ANT1_PWR
3.3
5
5.5
V
< 100mA
Secondary GNSS Antenna
ANT1_PWR
3.3
5
5.5
V
< 100mA

9
Item
Pin
Min
Typical
Max
Unit
Condition
Power Supply
Operating Temperature
Topr
-40
85
°C
Power Consumption
P
2.0
W
NOTE:
Since the product contains capacitors at the input, inrush current will occur during power-on.
Evaluate in the actual environment in order to check the effect of the supply voltage drop due to
the inrush current.
2.6 Physical Specifications
Table 2-5 Physical Specifications
Size
30×40×4 mm
Temperature
Operating : -40℃～+85℃
Storage: -55℃～+95℃
Humidity
95% No condensation
Vibration
GJB150.16-2009, MIL-STD-810
Shock
GJB150.18-2009, MIL-STD-810
3Hardware Design
3.1 Design in Considerations
Supply stable power to the VCC pin. Connect all the GND pins to ground
The module VCC power-on behavior is repeatable, the initial level is lower
than 0.4V, and the undershoot and ringing should be guaranteed to be
within 5% VCC
ANT1 and ANT2 MMCX interfaces supply +3.3~5.5 V feed. Fifty (50) ohm
impedance matching for ANT1 and ANT2 is strongly recommended
Ensure COM1 is connected to the host. COM1 is required for firmware
upgrades.
Only connect the module’s reset pin FRESET_N to ensure complete reset
of the module. It will restore the module to the manufacturing
configuration.
When ANT_NLOD, ANT_FFLG and antenna detection indication signal are
connected, IO without any pull-up/down of the client MCU terminal is
required at the input.
In order to obtain proper performance, special concerns should be paid during the
design to the following:

UM482 User Manual
10
Power supply: A stable and low ripple power supply is necessary for good
performance. Make sure the peak to peak voltage ripple does not exceed
50mVpp. It is recommended to use a power chip with current output
capacity greater than 2A to power the board.
−Use LDO to ensure the purity of the power supply
−Try to place LDO close to the module in layout
−Widen the tracks of power circuit or use copper pour surface to
transmit current
−Avoid walking through any high–power or high inductance devices
such as a magnetic coil
Interfaces: Ensure that the signals and baud rate of the main equipment
match those of the UM482 module
Antenna interface: Make sure the antenna impedance matches, and the
cable is short without any kinks, try to avoid all acute angles
Try to avoid designing in any circuits underneath UM482
This module is a temperature sensitive device, so dramatic changes in temperature
will result in reduced performance. Keep it away as far as possible from any high-
power high-temperature air and heating devices
3.2 UM482 Reference Design
Figure 3-1 Minimum Reference Design

11
Figure 3-2 UM482 Reference Design
3.3 Pins
Table 3-1 Pin Sequence
Pin Name
Pin
I/O
Description
Integration Notes
Power
Supply
VCC
31, 32
power
Voltage
Supply
Stable, clean, low ripple power
supply - peak ripple power lower
than 50mV is preferred
ANT1_PWR
ANT2_PWR
5, 46
power
Antenna
Power
Supply
Voltage supply for active antenna
GND
1, 3, 4,
6, 9, 14,
18, 25,
33, 34,
43, 47,
52, 55,
57, 58,
60
power
Ground
Connect all the GND signals to
ground. Better to use copper
pour surface.

UM482 User Manual
12
Pin Name
Pin
I/O
Description
Integration Notes
Antenna
ANT1_IN,
ANT2_IN
2, 59
I
Satellite
signal input
50 Ω impedance matching
UART
TXD1
35
I
COM1
Transmit
Data
COM1 output, leave
unconnected if not used
RXD1
36
O
COM1
Receive Data
COM1 input, leave unconnected
if not used
TXD2
37
I
COM2
Transmit
Data
COM2 output, leave
unconnected if not used
RXD2
38
O
COM2
Receive Data
COM2 input, leave unconnected
if not used
TXD3
39
I
COM3
Transmit
Data
COM3 output, leave
unconnected if not used
RXD3
40
O
COM3
Receive Data
COM3 input, leave unconnected
if not used
System
FRESET_N
22
I
Hardware
Reset (low
effective)
FRESET_N requires more than 5s
to reset the module to factory
default.
Don’t connect it if not used
PPS
44
O
PPS signal
EVENT
45
I
EVENT signal

13
3.4 PCB Packaging
Figure 3-3 UM482 Recommended PCB Packaging (unit: mil, in brackets: mm)
3.5 Reset Signal
If the user resets the module via RST_N pin after power on, some configuration setting
should proceeded in order for the UM482 module to perform correctly. The RST_N
and power supply must meet the following timing sequence requirement. The RST_N
reset signal should last more than 5ms to be effective.
VCC
RST_N
> 5ms
Figure 3-4 UM482 RST_N Timing Sequence

UM482 User Manual
14
3.6 External Antenna Feed Design
UM482 feeds the antenna signals to the required circuits internally, but in order to
effectively prevent damage from lightning and surges, circuit protection should be
installed externally to protect the module.
High voltage and high-power protection chips should be used to feed the antenna from
the outside of the module. Gas discharge tube, varistor, TVS tube and other high-
power protective devices may be used in the antenna circuit to effectively improve the
prevention against lightning stroke and surge.
UM482
ANT1_IN
ANT1_BIAS
ANT1
ANT1_PWR
GND
L1
C2
C1
ANT2_PWR
ANT2_IN
L2
ANT2_BIAS
ANT2
C3
C4
Figure 3-5 UM482 External Antenna Feed Reference Circuit
Remarks:
a) L1 and L2, feed inductor, 68nH RF inductor in 0603 package is recommended
b) C1 and C3, decoupling capacitor, it is recommended to connect two capacitors of
100nF/100pF in parallel;
c) C2 and C4, DC blocking capacitor, recommended 100pF capacitor.

15
4Installation and Configuration
4.1 ESD Handling Precautions
UM482 Module is an ESD sensitive device and special precautions when handling are
required.
Electrostatic discharge may cause damages to the device. All operations
mentioned in this chapter should be carried out on an antistatic workbench,
wearing an antistatic wrist strap and a using a conductive foam pad
Hold the edge of the module, and do NOT directly touch the electronic
components
The users may assemble UM482 flexibly according to the following application
scenarios. The following figure shows a typical installation of the UM482 with
Evaluation Kit (EVK).
4.2 Hardware Installation
Figure 4-1 Typical Installation of UM482
Please inspect the shipping cartons for any signs of damage or mishandling before
unpacking the UM482 package. The following items are required to install the UM482
correctly:
UM482 EVK suite (or evaluation board)
User manual
UPrecise software
Qualified antenna
MMCX antenna cable

UM482 User Manual
16
PC or laptop with serial ports (Windows 7 or above), with UPrecise installed
Follow the steps below to install:
Step 1: Fix UM482 board on the EVK with the holes and pins aligned accurately.
Figure 4-2 Installation Instruction
Step 2: Choose the correct location for the antenna- this is critical for a high-
quality installation. Poor or incorrect placement of the antenna can influence
accuracy and reliability and may result in damage during normal operation. Use
the coaxial radio frequency cable to connect the antenna connector of UM482
EVK;
NOTE: The RF connector on the board is MMCX - the suitable connecting wire should be
selected according to the package. The input signal gain at the antenna interface is optimally
between 20 and 36 dB. Please select the appropriate antenna, antenna cable and online LNA
accordingly.