Globalstar STX3 User manual

USER MANUAL
STX3 DEVELOPMENT KIT
WITH BLE TECHNOLOGY
9150-0137-01 R-2

TABLE OF CONTENTS
INTRODUCTION........................................................................................................................ 1
PURPOSE ..........................................................................................................................................................1
APPLICABLE DOCUMENTS .................................................................................................................................1
DEV KIT INCLUDES ............................................................................................................................................1
Dev Kit Board..............................................................................................................................................1
Long USB Y-Cable........................................................................................................................................1
DESCRIPTION ....................................................................................................................................................2
Key Features of the STX3 Dev Kit with BLE....................................................................................................2
APPLICATION ........................................................................................................................... 3
OPERATION OF GLOBALSTAR COMMERCIAL IOT NETWORK .................................................................................3
DEV KIT BLOCK DIAGRAM ..................................................................................................................................3
DESIGN DETAILS ...................................................................................................................... 3
Location of the features on the Dev Kit ..........................................................................................................4
DEV KIT SCHEMATIC ..........................................................................................................................................5
DEV KIT COMPONENT LOCATION .............................................................................................. 6
SETTING UP THE DEV KIT......................................................................................................... 7
DOWNLOADING SMARTPHONE APPS ..................................................................................................................7
SOFTWARE TOOLS FOR DOWNLOADING FIRMWARE ONTO THE DEV KIT ..............................................................7
QUICK TEST OF DEV KIT OPERATION ..................................................................................................................8
Steps for the Quick Test ...............................................................................................................................8
USING THE SERIAL INTERFACE WITH THE DEV KIT ............................................................................................8
USING THE STX3 DK-BLE SMARTPHONE APP WITH THE DEV KIT......................................................................10
SUMMARY OF STX3 COMMANDS ......................................................................................................................12
NOTES .....................................................................................................................................................12
HARDWARE DESCRIPTION ...................................................................................................... 13
STX3 Module.............................................................................................................................................13
Bluetooth..................................................................................................................................................13
Power Supplies..........................................................................................................................................13
Dev Kit Power Circuitry...............................................................................................................................14
LED’s........................................................................................................................................................14
Buttons.....................................................................................................................................................14
Sensors.....................................................................................................................................................15
USB Interface ...........................................................................................................................................16
Connector Interfaces ..................................................................................................................................16
Test Points ................................................................................................................................................16
REFERENCES ......................................................................................................................... 17
REGULATORY APPROVAL ........................................................................................................ 18
RADIO ASTRONOMY SITE AVOIDANCE...............................................................................................................18
REGULATORY NOTICES ....................................................................................................................................18
APPENDIX A – STX3 DEVELOPMENT KIT SCHEMATIC ................................................................. I
APPENDIX B – STX3 DEVELOPMENT KIT BILL OF MATERIAL LISTS ............................................ X
TRANSMITTER BOARD BILL OF MATERIAL ..........................................................................................................X
MAIN BOARD BILL OF MATERIAL.......................................................................................................................XI

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PURPOSE
This document describes the physical, electrical, and functional characteristics of the STX3 Development Kit with
Bluetooth Low Energy technology and operation of its associated serial interface and smartphone applications. The
information contained in this document is intended to provide the end user with the necessary technical information
required to use the STX3 Development Kit with BLE, hereby referred to as the Dev Kit.
This document is intended to be used by engineers and technical management and assumes a general knowledge
of basic engineering practices by the user.
APPLICABLE DOCUMENTS
• Globalstar STX3 User Manual
• Globalstar STX3 Development Kit with BLE Technology Quick Start Guide
• Globalstar STX3 Development Kit with BLE Software Design Guide
DEV KIT INCLUDES
When opening the Dev Kit box, it will include the following items shown:
INTRODUCTION
DEV KIT BOARD
Transmitter and Main board stacked on top of each other. The Dev Kit is pre-
programmed with demonstration firmware that supports the BLE app, serial
command communication and quick test function.
LONG USB Y-CABLE
The USB Y-cable is used for connecting the Dev Kit to the host computer.

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DESCRIPTION
At the heart of the Dev Kit is the Globalstar STX3 module. The STX3 module is a simplex Satellite transmitter
designed to send small packets of user defined data to a network of low earth orbiting (LEO) satellites using the
Globalstar Commercial IoT Network. The received data is then forwarded to a user defined network interface that
may be in the form of an FTP host or HTTP host where the user will interpret the data for further processing.
The STX3 is a surface mount module and it is mounted on the bottom side of the Transmitter board just under the
Taoglas antenna. The STX3 is electrically connected to the Nordic Bluetooth processor through the two headers that
attach the two PCBs of the Dev Kit together. Also, the Main PCB provides power, an RF connection to the transmit
antenna, and communications with a host processor which will control the operation of the STX3.
KEY FEATURES OF THE STX3 DEV KIT WITH BLE
• Globalstar Satellite Transmitter (STX3)
• nRF52832 flash-based ANT/ANT+, Bluetooth® low energy SoC solution
(https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52832)
• 2.4GHz Chip Antenna for Bluetooth
• Multiple Interfacing Options: BLE, USB, STX3 UART
• User Controllable LEDs and button
• Humidity Sensor
• Temperature Sensor
• (3-axis) Accelerometer
• Analog adjust potentiometer
• Expansion header
• Sample code and hardware files available upon request
• Mobile App available for iOS and Android

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OPERATION OF GLOBALSTAR COMMERCIAL IOT NETWORK
The STX3 Dev Kit transmits messages over the Globalstar LEO (Low Earth Orbit) satellite network. These satellites
continuously orbit the planet and can communicate with Globalstar devices that are within range of its current
position. For additional information about the operation of the Globalstar network, please see the STX3 User Manual.
DEV KIT BLOCK DIAGRAM
The block diagram of the Dev Kit is shown below:
The Dev Kit design is a basic implementation of the STX3 module with a power source (host computer), a USB
interface, user LEDs and buttons and a few peripheral sensors. The Dev Kit is a robust extension of the Reference
Design described in the STX3 User Manual.
The Dev Kit allows the hardware designer or firmware developer the platform to easily evaluate the STX3 and provide
a platform for quickly creating new products.
The block diagram shown in Figure 1 represents the features of the two boards and interfaces.
• Transmitter Board - The transmitter board consists of the STX3 module, patch antenna, and power supply for
the STX3 RF transmitter. A standard 4 signal UART interface (not RS232) is the direct method to communicate
with the STX3 module. The STX3 module includes test pins that make it easy to quickly verify the functionality of
the satellite communication.
• Main Board - The main board includes the Bluetooth Low Energy (BLE) microcontroller by Nordic
Semiconductor, accelerometer, temperature/humidity sensor, resistive potentiometer, two buttons, two LED’s,
USB interface, and expansion port.
Figure 1 - STX3 Dev Kit with BLE Block Diagram
APPLICATION
DESIGN DETAILS

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LOCATION OF THE FEATURES ON THE DEV KIT
A. Satellite Patch Antenna for STX3
B. Temperature/Humidity Sensor
C. Accelerometer
D. User button. Pressing button initiates STX3 test message packet to be transmitted
E. Reset button, for Nordic processor
F. Green and Red Indicator LED’s connected to processor
G. JTAG(SWD) programming header for Nordic processor
H. BLE chip antenna
I. Green LED indicates when RF power supply is enabled. LED is only ON during STX3 transmission
J. Expansion Header connected to processor
K. Analog potentiometer
L. USB connector, for applying power and serial terminal interface
M. Label with ESN number. Required for registration of STX3 module in Globalstar network
N. Green LED, indicates voltage output from main power supply
O. Two pin header (disables main power supply when shunt is connected across both header pins)
A
B
C
D
E
F
G
H
I
J
K
L
N
M
O

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DEV KIT SCHEMATIC
The schematic is shown in Appendix A. The schematic consists of 9 pages organized with pages 3-5 for the circuitry
on the Transmitter board and pages 5-9 for the circuitry on the Main board. The descriptions below explain a high-
level description of each schematic page and its associated circuitry:
1. Title Page (page 1)
Includes notes on changes between the revisions of the schematic and the Table of Contents for the schematic.
2. Block Diagram (page 2)
Hardware architecture of the boards with interfaces to each of the boards.
3. STX3 Transmitter module (page 3)
This includes the STX3 transmitter with interface circuitry. All of the circuitry on this page is located on the
Transmitter board.
4. RF Power supply (page 4)
The power supply dedicated for the RF section of the STX3 module. The buck/boost power supply is enabled
and disabled by the STX3 module during transmission. The power supply is disabled when the STX3 is not
transmitting. Review the STX3 data sheet on details regarding time the RF power supply is enabled. All of the
circuitry on this page is located on the Transmitter board.
5. Interface Connector and Expansion (page 5)
This page includes the interface headers between the Transmitter board and the sockets on the Main board.
Also, included are the expansion header connected to the Nordic processor and a header that interfaces directly
with the STX3 module.
6. BLE Nordic processor (page 6)
This page includes the Nordic BLE processor, BLE chip antenna, processor controlled LED’s, SWD JTAG header,
reset button, user button, and all supporting components for the processor. All of the circuitry on this page is
located on the Main board.
7. Sensors (page 7)
The sensors include 3 axis accelerometer, humidity/temperature sensor, and analog adjust resistor
potentiometer. All the circuitry on the page is located on the Main board.
8. USB and Power Input (page 8)
The USB port provides power to the Dev Kit and allows for terminal communication to the Nordic processor. All
the circuitry on this page is located on the Main board.
9. Power Supply (page 9)
This is the main power supply for the Dev Kit and converts the USB 5V power to 3.3V. The 3.3V from this supply
is used by Transmitter and Main board. On the Transmitter board it supplies the logic voltage for the STX3
module, and supplies voltage for all of the circuitry on the Main board. Please note the 3.3V voltage does not
supply power to the RF transmitter of the STX3 module on the Transmitter board. All the circuitry on this page is
located on the Main board.

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Figure 2 - STX3 Dev Kit Component Location - Top Side of PCB
Figure 3 - STX3 Dev Kit Component Locations - Bottom Side of PCB
DEV KIT COMPONENT LOCATION
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
STX3, TX output power -40 to +85° C, VRF=3.3 volts 18.0 18.5 19.0 dB
STX3, Transmit mode supply
current, Transmitter board -40 to 85º C, VRF=3.3 volts 315 325 350 mA
Operating Temperature Range 0-40 C
Power Supply Operational Range 1.8V - 5.2V
Table 1 - STX3 Dev Kit Operating Conditions & Parameters

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SETTING UP THE DEV KIT
There are 3 main communication interfaces for the Dev Kit. These are BLE, USB and the user push-button.
For controlling operation of the Dev Kit, a user may use either the downloadable smartphone app (iOS or Android)
or the serial interface. Commands are used to send information over the simplex network, read from the on-board
sensors, and monitor the internal operation of the STX3. Refer to the STX3 User Manual for a complete description
of all commands.
DOWNLOADING SMARTPHONE APPS
Globalstar provides a free smartphone App that allows BLE communication with the Dev Kit. The app is available on
the Apple App Store for iOS and Google App Store for Android. Search either app store for Globalstar and locate the
one named STX3DK BLE. After downloading the app, enable Bluetooth on your phone; as the STX3DK-BLE app can
only communicate with the Dev Kit if Bluetooth is enabled on your phone.
The STX3DK-BLE app icon is shown below.
SOFTWARE TOOLS FOR DOWNLOADING FIRMWARE ONTO THE DEV KIT
The Nordic nRF52832 processor is pre-programed with firmware that supports:
a. Communication with the BLE app
b. Terminal commands with a host computer using the USB connection
c. A quick test feature
The Dev Kit supports developing your own firmware using the development environment of your choice but using
the Nordic SDK environment is recommended.
The Dev Kit was designed for easy connection using the Segger JLink tool:
SEGGER J-Link Tool and Software - The J-Link tool is helpful to debug and program the Nordic processor. The
J-Link tool is not included with the Dev Kit but can be purchased directly from Segger (or Digikey, Mouser, etc.).
The Dev Kit uses the SWD interface (SWDIO, SWCLK, Reset, Ground) to interface with the Nordic processor. On
the Main board, reference designator J10 is a 2x10 header that matches the SWD interface pin out of the Segger
J-Link tool.
The main board also includes test points TP19, TP20, TP21, and TP23 that are connected to SWD signals. This will
allow for connecting to other tools of your choice.
Additional information regarding the programming of the Dev Kit can be found in the STX3 DK-BLE Software Design
Guide and is available from your Globalstar representative.
Figure 4 - STX3DK-BLE App Icon

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QUICK TEST OF DEV KIT OPERATION
The quick test will have you receiving a message from the STX3 message within minutes. It is recommended that
you run the quick test after first receiving the Dev Kit. The quick test does not require the smartphone App and will
provide a quick method for sending a test message packet through the Globalstar network. After registering the ESN
for your Dev Kit with Globalstar, the network will direct your messages from the Dev Kit to what you designated with
your provided route (email, URL, etc.). The Dev Kit will need to be connected to a host computer for powering it up.
STEPS FOR THE QUICK TEST
1. Place Dev Kit board in a location outside with a clear view of the sky.
2. Connect the supplied host computer to the development kit using the provided USB Y-cable.
3. Once power is applied to the Dev Kit you will see three LEDs illuminate. The blinking LEDs (LD3 & LD4) indicate
that the processor is running and the system is ready. The solid green LED (LD2) will indicate the main power
supply is enabled. The processor will boot in approximately 2 seconds.
4. Simply press the USER button located on the Main board of the Dev Kit. After pressing the USER button, a
green LED(LD1) on the Transmitter board will turn on for approximately 1 second and red LED on the main
board will stay on. The STX3 is transmitting when this green LED is on. The STX3 module will transmit the same
test message packet 3 times with a random delay between messages of 5-10 minutes. Each time the STX3
transmits, the green LED will briefly turn on and the message will be transmitted. The red LED (LD3) will stay red
until all 3 messages have been transmitted.
5. The route used for the registered ESN of the Dev Kit will receive the test message packet. It may take between to
5-20 minutes to receive the message.
The quick test transmits the test message packet as defined in the STX3 User Manual.
USING THE SERIAL INTERFACE WITH THE DEV KIT
When interfacing a host computer to the Dev Kit, two USB ports on the host computer or USB hub are required.
Use the USB Y-cable provided with the Dev Kit to connect between the Dev Kit and the host computer. Both Type-A
USB connectors must be connected to the host computer.
The Dev Kit will appear to the host computer as a virtual COM port and will be ready to communicate with the
following settings.
• Baud Rate - 115200
• Bits - 8
• Parity - None
• Stop bits – 1
A serial terminal program (for example, puTTY) can be used to communicate and configure the device. Once
connected, the “?” command can be used to display a list of command options.
A simple, text-based command infrastructure has been built to provide these examples. Each command has a
unique command name, followed by one or more arguments. The end of the command is indicated by end of line
characters. This same serial command interface is used for both BLE and USB communications.