AsteRx4 to AsteRx-m3 transition:

technical considerations

Version 1.0.0
AsteRx4 to AsteRx-m3 transition: technical considerations

Version 1.0.0

October 8, 2020

© Copyright 2000-2020 Septentrio nv/sa. All rights reserved.

Septentrio
Greenhill Campus, Interleuvenlaan 15i
3001 Leuven, Belgium

http://www.septentrio.com
Phone: +32 16 300 800
Fax: +32 16 221 640
@septentrio

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1 Table of contents

1 TABLE OF CONTENTS ....................................................................................................... 3

2 INTRODUCING THE ASTERX-M3 ..................................................................................... 4

3 WHAT DOES THE ASTERX-M3 BRING?............................................................................ 5

4 ASTERX4 TO ASTERX-M3 TRANSITION: TECHNICAL CONSIDERATIONS................... 6

4.1 Product comparison.................................................................................................... 6

4.2 Connectivity .................................................................................................................. 7

4.3 RF Interface................................................................................................................... 7

4.4 Frequency Reference Output (REF OUT).................................................................. 7

4.5 USB.................................................................................................................................. 8

4.6 Ethernet ......................................................................................................................... 8

4.7 GPIO................................................................................................................................ 8

5 SOFTWARE ......................................................................................................................... 9

6 WHAT ASTERX-M3 PRODUCT FITS THE BEST MY ASTERX-4?.................................... 10

APPENDIX: ASTERX4 80 PIN CONNECTOR REMAP ......................................................... 11

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2 Introducing the AsteRx-m3

The AsteRx-m3 is a state-of-the-art GNSS receiver family using triple frequency and multi-

constellation GNSS technology both for maximal positioning availability and reliability in

challenging conditions. The AsteRx-m3 product family includes both base station and

rover receivers in single or dual antenna configuration.

The AsteRx-m3 product family provides RTK positioning at the lowest power consumption
of any comparable device on the market,

The new product family includes 3 types of GNSS OEM boards.

AsteRx-m3 Pro is the rover receiver tracking signals from all available GNSS constellations

on 3 frequencies. Simple and powerful, it operates both in single and dual antenna modes.

The AsteRx-m3 ProBase, as its name suggests, is a product designed to operate as a base

station for RTK and PPP-RTK networks.

Last but not least is the AsteRx-m3 Pro+, the best-in-class full-feature OEM receiver board

flexible enough to fit into any application and to be used either as a rover or a base station

in a single or a dual antenna mode.

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3 What does the AsteRx-m3 bring?

Compared to the current AsteRx4 the AsteRx-m3 product family brings significant SWaP

improvements reducing the footprint to 47 mm by 70 mm and the maximum power

consumption about 4 W to ~1.8 W. The size and power reduction is obtained with no

performance compromise.

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4 AsteRx4 to AsteRx-m3 transition: technical

considerations

The AsteRx-m3 product family is designed to provide a functional equivalent of the

AsteRx4 but on a reduced footprint and a lower power consumption. In particular the

AsteRx-m3 Pro+, which is the top of the line receiver, provides the same number of

channels and the same flexibility to work in single or dual antenna..

4.1 Product comparison

AsteRx4 AsteRx-m3 AsteRx-m3 Pro AsteRx-m3

Pro+ ProBase
Dimensions 76.4 x 100 mm
3.03 x 3.93 in
47.5 x 70 x 9.32 mm
No break off edges
1.87 x 2.75 x 0.36 in
61 x 88.5 mm
2.4 x 3.48 in
Weight 27 g / 0.952 oz
55 g / 1.94 oz

Input Voltage 3 - 5.5 VDC 3.3 VDC ± 5%

Maximum antenna
200 mA 150 mA
current
Max power
4.3 W 1.86 W 1.18 W
consumption
Heading Optional Yes Optional NA
Max data rate
100 Hz 100 Hz 10 Hz 10 Hz
(measurements)
Ethernet PHY on board RMII interface 1 RMII interface 1 RMII interface 1
PPSOut 1 1 1
1
HW ready for 2 HW ready for 2 HW ready for 2
RF connectors 2 MMCX
2 MMCX 90 deg 2 MMCX straight2 MMCX straight2
straight2
Ref In NA Yes NA NA
Ref Out On 80 pin Dedicated uFL

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refer to the AsteRx-m3 hardware manual for a reference design and recommendations

for the PHY selection and integration.

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Variants with u.FL connectors and 90 deg MMCX connectors are foreseen for volume

integrations. Contact your sales representative (sales@septentrio.com) for MOQ, pricing,

part numbers and availability

4.2 Connectivity

The AsteRx4 features an 80 pin connector while the AsteRx-m3 product family connectivity

is brought via a 30 pin connector (for basic interfacing) and a 60 pin connector for a more

advanced usage.

The detailed mapping of the 80 pin connector of the AsteRx4 to the 30 and 60 pin
connectors of the AsteRx-m3 can be found in Appendix.

4.3 RF Interface

The following changes apply to the RF interface.

► Antenna net gain range of the AsteRx-m3 is 15-45 db as opposed to 15-50 db for

AsteRx4

► The antenna current limit has changed from 200 mA per antenna to 150 mA.

4.4 Frequency Reference Output (REF OUT)

REF OUT

The frequency reference used by the receiver is available at the REFOUT u.FL connector.

The signal on this pin provides a 10MHz square wave between 0 - 2.8 V with a 50 Ohm

impedance.

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 The REFOUT signal – enabled by default - can be switched on and off via the

setREFOUTmode command.

4.5 USB

By default, AsteRx-m3 is configured in USB 2.0 mode. AsteRx4 is configured in 1.1 mode

by default.

We recommend USB 2.0 when designing in the AsteRx-m3.

4.6 Ethernet

The AsteRx4 receiver features an on board Ethernet PHY. The AsteRx-m3 product family

requires the integration of an external PHY. Please refer to the AsteRx-m3 hardware

manual for a reference design and recommendations for the PHY selection and

integration.

4.7 GPIO

While the AsteRx4 has 3 General Purpose output pins, the AsteRx-m3 product family

features only 2. Please see details on the AsteRx-m3 Hardware Manual.

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5 Software

The following aspects should be accounted for in the software integration:

► The list of RTCM3 messages enabled by default in an output stream has changed:

AsteRx-m3: 1006, 1033, 1230, 1074, 1084, 1094 and 1194

AsteRx-m2/m2a: 1006, 1033, 1230, 1004, 1012

While different product names differentiate the AsteRx-m3 product variants, the

hostname follows the same syntax as all our products, i.e. asterx-m3-1234567 with

1234567 representing the serial number of the reciever.

► Wakeup on COM1 activity is not available on the AsteRx-m3 product family

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6 What AsteRx-m3 product fits the best my

AsteRx-4?

The AsteRx-m3 Pro+ is the product that matches the best the current AsteRx-4 use cases,

but in order to make sure that you do purchase the best option for your platform we

advice you to contact your local sales representative.

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Appendix: AsteRx4 80 pin connector remap
AsteRx4 AsteRx-m3
Pin Name Typ Level Description Connector Pin Correspondin Remark
# e # g pin name
1 Gnd Gnd 0 Ground. GND
3 USB_D- I/O USB USB data signal 30-pin 6 USB_D- USB 2.0
negative D-. default
5 USB_D+ I/O USB USB data signal 30-pin 5 USB_D+ USB 2.0
positive D+. default
7 Gnd Gnd 0 Ground. GND
9 Reserved Reserved for future
use
11 LANLED O LVTTL LAN link and activity Not available,
indicator, see Ethernet PHY
Appendix A of the not installed
AsteRx4 HW manual on the
AsteRx-m3
board.
13 Reserved Reserved for future
use
15 Vin P 3.0V Main power supply 30-pin 1 Vin Voltage range
<Vin input. reduced to
<5.5V 3.3V +/-5%.
Shall also be
connected to
pin 2.
17 Gnd Gnd 0 Ground. GND
19 SCOM_RX1 I LVTTL Serial COM 1 receive 30-pin 10 RX1
line (inactive state is
high). Disabled when
pin#69 is tied to
ground.
21 SCOM_RX2 I LVTTL Serial COM 2 receive 30-pin 14 RX2
line (inactive state is
high). Disabled when
pin#69 is tied to
ground.
23 SCOM_RX3 I LVTTL Serial COM 3 receive 30-pin 16 RX3
line (inactive state is
high)
25 SCOM_RX4 I LVTTL Serial COM 4 receive 60-pin 16 RX4
line (inactive state is
high).
27 Gnd Gnd 0 Ground. GND
29 VCC_3V3_OUT P 3.3V 3.3V power supply the
output (10mA max), or VCC_3V3_OUT
0V if the receiver is in pin is taken
sleep or stand-by over by the
mode. IO_EN pin on
AsteRx-m3. It
is the pin that
can be used
to enable
input buffers
(see warning
in both
manuals)
31 Reserved Reserved for future
use
33 Gnd Gnd 0 Ground. GND
35 EVENT_B I LVTTL Event B input (see 60-pin 57 For both
Firmware User events: the

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 Manual for operation pin is pulled-
instructions) down on
AsteRx-m3.
37 Gnd Gnd 0 Ground. GND
39 REF_O O LVTTL Output depends on u.FL Signal now
the EXTREF_STAT pin available on a
level: EXTREF_STAT dedicated
left open: 10-MHz u.FL
square wave output connector.
from the internal
frequency reference.
EXTREF_STAT tied to
ground: REF_O is
disabled.
41 Gnd Gnd 0 Ground. GND
43 REF_I I LVTTL 10-MHz square wave 60-pin 60 REF_IN Sine wave or
frequency reference a square
input. Input ignored wave with a
when EXTREF_STAT is peak-to-peak
left open. amplitude
between 2V
and 5V.
Always used
when
provided.
Not hot-
swappable.
45 SCOM_CTS2 I LVTTL Serial COM 2 CTS line 60-pin 12 CTS2
47 SCOM_CTS3 I LVTTL Serial COM 3 CTS line 60-pin 14 CTS3
49 LOGLED O LVTTL Internal logging status 30-pin 27 LOGLED Max output
indicator, see current:
Appendix A. 10mA.
51 TRACKLED O LVTTL Tracking status Not available,
indicator, see GPLED signal
Appendix A. can be used.
53 GP1 O LVTTL GP1 in 60-pin 9 GP1
setGPIOFunctionality
command.
55 EXTREF_STAT I LVTTL Sets the source of the Not available
10-MHz frequency
reference (internal or
external).
57 Gnd Gnd 0 Ground. GND
59 Reserved Reserved for future
use
61 SD_CMD O LVTTL SD card CMD line 30-pin 28 SD_CMD
63 SD_CLK O LVTTL SD card CLK line 30-pin 26 SD_CLK
65 Reserved Reserved for future
use
67 Gnd Gnd 0 Ground. GND
69 TTLnRS232 I LVTTL LVTTL vs RS232 Not available,
selection for COM1 the AsteRx-
and COM2. Internal m3 only
pull up. support
LVTTL serial
port.
71 Reserved Reserved for future
use
73 ETH_TX+ O Etherne Ethernet TX+ Not available,
t Ethernet PHY
not installed
on the
AsteRx-m3
board. Please
refer to
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 chapter TBD
for a
description
on how to
integrate
Ethernet on
the AsteRx-
m3
75 ETH_TX- O Etherne Ethernet TX- Not available,
t Ethernet PHY
not installed
on the
AsteRx-m3
board. Please
refer to
chapter TBD
for a
description
on how to
integrate
Ethernet on
the AsteRx-
m3
77 ETH_RX+ I Etherne Ethernet RX+ Not available,
t Ethernet PHY
not installed
on the
AsteRx-m3
board. Please
refer to
chapter TBD
for a
description
on how to
integrate
Ethernet on
the AsteRx-
m3
79 ETH_RX- I Etherne Ethernet RX- Not available,
t Ethernet PHY
not installed
on the
AsteRx-m3
board. Please
refer to
chapter TBD
for a
description
on how to
integrate
Ethernet on
the AsteRx-
m3

2 Gnd Gnd 0 Ground. GND

4 USB_Vbus P 4.35V≤V USB Power. Cannot 30-pin 7 USB_Vbus
high≤5. be used to power the
25V receiver.
6 Gnd Gnd 0 Ground. GND
8 nPWR_TOGGL I LVTTL Power toggling input, Not available.
E active negative. The AsteRx-
Applying a negative m3 uses a
pulse to this pin level-based
orders the receiver to nPDN state
enter stand-by mode signal to
if it was operating, define it's

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 and to start operation operation
if it was in stand-by mode instead
mode (see section of a state
2.10 of this transition
document). input as a
pulse.
10 nRST_IN I LVTTL Reset input, active 30-pin 8 nRST TBC: The
negative. Receiver AsteRx-m3
resets when driven stays in reset
low for at least 1ms. mode as long
The net effect is as the pin is
similar to shortly driven low.
disconnecting the
power supply.
12 Reserved Reserved for future
use
14 Vantenna P 3.15V<V Antenna supply, max 30-pin 18 VANT The AsteRx-
ant<12 current per antenna m3 allowed
V 200mA. The voltage voltage input
provided on this pin is is reduced to
transferred to the 3<VANT<5.5V.
central conductor of The
the antenna MMCX maximum
connectors. current per
antenna is
150mA.
16 Vin P 3.0V<Vi Main power supply 30-pin 2 Voltage range
n<5.5V input reduced to
3.3V +/-5%.
Shall also be
connected to
pin 1.
18 Gnd Gnd 0 Ground. GND
20 SCOM_TX1 O LVTTL Serial COM 1 transmit 30-pin 9 TX1
line (inactive state is
high)
22 SCOM_TX2 O LVTTL Serial COM 2 transmit 30-pin 13 TX2
line (inactive state is
high)
24 SCOM_TX3 O LVTTL Serial COM 3 transmit 30-pin 15 TX3
line (inactive state is
high)
26 SCOM_TX4 O LVTTL Serial COM 4 transmit 60-pin 15 TX4
line (inactive state is
high)
28 Gnd Gnd 0 Ground. GND
30 Reserved Reserved for future
use
32 Gnd Gnd 0 Ground. GND
34 EVENT_A I LVTTL Event A input (see 30-pin 19 Both events
Firmware User can be
Manual for operation utilized for
instructions) time-
synchronizati
on.
Permission
dependent.
36 Gnd Gnd 0 Ground. GND
38 PPSout O LVTTL PPS output. See 30-pin 12 PPSout
section 2.5.
40 Gnd Gnd 0 Ground. GND
42 SSNIn1 I LVTTL Proprietary input

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 44 Button I LVTTL Input can be 30-pin 25
connected to a push
button, used to
enable and disable
internal SBF and
NMEA logging. High to
low transitions are
detected as “button
pressed” events.
46 SCOM_RTS2 O LVTTL Serial COM 2 RTS line 60-pin 11 RTS2
48 SCOM_RTS3 O LVTTL Serial COM 3 RTS line 60-pin 13 RTS3
50 GPLED O LVTTL General-purpose 30-pin 22 GPLED
status indicator, see
Appendix A.
52 GP3 O LVTTL GP3 in Not available,
setGPIOFunctionality the AsteRx-
command. m3 only
features 2
General
Purpose pins
54 GP2 O LVTTL GP2 in 60-pin 44 GP2
setGPIOFunctionality
command.
56 PVTLED O LVTTL PVT status indicator, Not available,
see Appendix A. GPLED can be
used to
provide the
same
functionality.
58 Gnd Gnd 0 Ground. GND
60 Reserved Reserved for future
use
62 SD_DAT0 I/O LVTTL SD card DAT0 line 30-pin 30 SD_DAT0
64 Reserved Reserved for future
use
66 Reserved Reserved for future
use
68 Gnd Gnd 0 Ground. GND
70 Reserved Reserved for future
use
72 ETH_BIAS P Etherne Bias pin for centre tap Not available,
t of Ethernet Ethernet PHY
transformer not installed
on the
AsteRx-m3
board. Please
refer to
chapter TBD
for a
description
on how to
integrate
Ethernet on
the AsteRx-
m3
74 RS232_TX1 O RS232 Serial COM 1 transmit Not available,
line (RS232 level) the AsteRx-
m3 only
support
LVTTL serial
port.
76 RS232_RX1 I RS232 Serial COM 1 receive Not available,
line (RS232 level) the AsteRx-
m3 only
support

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 LVTTL serial
port.
78 RS232_TX2 O RS232 Serial COM 2 transmit Not available,
line (RS232 level) the AsteRx-
m3 only
support
LVTTL serial
port.
80 RS232_RX2 I RS232 Serial COM 2 receive Not available,
line (RS232 level) the AsteRx-
m3 only
support
LVTTL serial
port.

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