ST STEVAL-FKI433V1 User manual

December 2016
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www.st.com
UM2149
User manual
Getting started with the S2-LP development kits
Introduction
This document describes the development kits for the S2-LP device and related hardware and software
components.
The S2-LPisan ultra low-power, low data rate, sub-1 GHz transceiver.
The following S2-LP kits are available:
1. S2-LP development platform for 430-470 MHz (order code: STEVAL-FKI433V1)
2. S2-LP development platform for 860-940 MHz (order code: STEVAL-FKI868V1)
3. S2-LP development platform for 860-940 MHz with external FEM (order code: STEVAL-FKI915V1)

Contents
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Contents
1Overview .......................................................................................... 6
1.1 System requirements ........................................................................6
1.2 STSW-S2LP-DK development kit setup............................................6
2Hardware description...................................................................... 7
2.1 STEVAL-FKI868V1 and STEVAL-FKI433V1 evaluation boards .......7
2.1.1 S2-LP connections ............................................................................. 8
2.1.2 STEVAL-FKI868V1 and STEVAL-FKI433V1 power .......................... 9
2.2 STEVAL-FKI915V1 evaluation board................................................9
2.2.1 S2-LP connections ........................................................................... 10
2.2.2 STEVAL-FKI915V1 power................................................................ 11
2.3 NUCLEO-L152 ................................................................................ 11
2.3.1 Push buttons..................................................................................... 11
2.3.2 LEDs ................................................................................................. 11
2.3.3 Embedded ST-LINK ......................................................................... 11
2.3.4 STM32L152RE microcontroller ........................................................ 11
2.4 Hardware setup............................................................................... 12
3GUI software description .............................................................. 13
3.1 Installation....................................................................................... 13
3.2 Detailed description......................................................................... 13
3.2.1 Connection panel.............................................................................. 15
3.2.2 Radio setting panel........................................................................... 15
3.2.3 RF test mode .................................................................................... 16
3.3 Packet setting.................................................................................. 17
3.3.1 Packet setting: BASIC ...................................................................... 17
3.3.2 Packet setting: WMBUS ................................................................... 18
3.4 Transmission test ............................................................................ 19
3.5 Low level commands....................................................................... 22
3.6 Running RSSI ................................................................................. 24
3.7 How to run a BER test using a signal generator.............................. 25
3.8 Register table.................................................................................. 26
3.9 Menu bar......................................................................................... 27
3.9.1 File .................................................................................................... 27
3.9.2 Tools ................................................................................................. 28
3.9.3 Help .................................................................................................. 30

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3.9.4 Device emulator................................................................................ 30
4Firmware examples ....................................................................... 31
5Release notes ................................................................................ 32
6License........................................................................................... 33
7 Revision history ............................................................................ 34

List of tables
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List of tables
Table 1: S2-LP: FKI868V1 and FKI433V1 evaluation board pin description..............................................8
Table 2: S2-LP: FKI915V1 evaluation board pin description....................................................................10
Table 3: STEVAL-FKI915V1 expansion board jumper description ..........................................................11
Table 4: Document revision history ..........................................................................................................34

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List of figures
Figure 1: STEVAL-FKI868V1 evaluation board features............................................................................7
Figure 2: STEVAL-FKI915V1 evaluation board features............................................................................9
Figure 3: NODE_L152RE disk drive .........................................................................................................13
Figure 4: Connection setup 1: 1 PC with S2-LP-DK GUI .........................................................................13
Figure 5: Connection setup 2: 2 PCs with S2-LP-DK GUI........................................................................14
Figure 6: S2-LP GUI main window ...........................................................................................................14
Figure 7: Available COM ports..................................................................................................................15
Figure 8: S2-LP radio setting ....................................................................................................................16
Figure 9: RF test mode buttons ................................................................................................................16
Figure 10: Basic packet setting panel.......................................................................................................17
Figure 11: wM-Bus packet setting panel...................................................................................................18
Figure 12: Transmission test panel...........................................................................................................19
Figure 13: Low level command panel .......................................................................................................22
Figure 14: Read/write register window .....................................................................................................23
Figure 15: Running RSSI tab....................................................................................................................24
Figure 16: BER test bench schema ..........................................................................................................25
Figure 17: Register table ..........................................................................................................................26
Figure 18: File list......................................................................................................................................27
Figure 19: Tool list ....................................................................................................................................28
Figure 20: Help menu ...............................................................................................................................30
Figure 21: S2-LP emulator........................................................................................................................30
Figure 22: IAR project ...............................................................................................................................31

Overview
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1 Overview
This section describes all the software and hardware components of the S2-LP kits.
1.1 System requirements
The STSW-S2LP-DK application GUI has the following minimum requirements:
•PC with Intel® or AMD® processor running Windows (XP SP3, Vista, 7 or 10)
•At least 128 Mb of RAM
•USB ports
•40 MB of available hard disk space
•Adobe Acrobat Reader 6.0 or above.
1.2 STSW-S2LP-DK development kit setup
Launch the S2-LP DK-Setup-X.X.X.exe file and follow the onscreen instructions.
EWARM Compiler 7.40.3 or later is required for building the
S2LPLibrary_Examples demonstration applications.

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2 Hardware description
2.1 STEVAL-FKI868V1 and STEVAL-FKI433V1 evaluation boards
The STEVAL-FKI868V1 and the STEVAL-FKI433V1 evaluation boards are designed to
work in the 860-940 MHz and in the 430-470 MHz band, respectively.
Some features on the boards are (see Figure 1: "STEVAL-FKI868V1 evaluation board
features"):
•S2-LP (A)
•8 MHz high frequency crystal (B)
•Balun, matching network and harmonic filter (C)
•Two rows with Arduino compliant connectors (D1-4)
•SMA connector (E)
•An EEPROM to store the manufacturing data (F)
•A NUCLEO-L152RE evaluation board (please refer to UM1724 for further details) (G)
•A jumper for S2-LP current measurement (H)
Figure 1: STEVAL-FKI868V1 evaluation board features
Pressing the reset button, the STM32 Nucleo development board resets and a hex format
string containing ID and PAC is shown.

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2.1.1 S2-LP connections
S2-LP signal test points are split across two rows which are Arduino compliant connectors:
CN1, CN3 and CN2, CN4.
The S2-LP shield is connected to the Nucleo motherboard via the Arduino compliant
connectors.
The connectors and pin names below are used in the STEVAL-FKIxxxV1 schematic
diagram.
Table 1: S2-LP: FKI868V1 and FKI433V1 evaluation board pin description
Pin name Pin number Arduino connectors
CN1 (D1) CN2 (D2) CN3 (D3) CN4 (D4)
VDD SMPS 1 pin 4
SMPS1 2
SMPS2 3
XOUT 4
XIN 5
SDN 6 pin 8(SDN)
VDDANASYNTH 7 pin 4
VRSYNTH 8
VREFVCO 9
VDDVCOTX 10 pin 4
TX 11
VRRF 12
RXN 13
RXP 14
VDDRXDIG 15 pin 4
SDO 16 pin 5 (MISO)
SDI 17 pin 4 (MOSI)
SCLK 18 pin 4(SCK)
CSN 19 pin 2 (CS)
GPIO0 20 pin 1 (GPIO0)
GPIO1 21 pin 3 (GPIO1)
GPIO2 22 pin 4 (GPIO2)
GPIO3 23 pin 6 (GPIO3)
VSMPS3 24
GND 25 pin 7 pins 6 and 7
The S2-LP evaluation board contains a discrete passive circuit for RF matching and balun
and other additional components required by the S2-LP for proper operation.

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2.1.2 STEVAL-FKI868V1 and STEVAL-FKI433V1 power
The board can be powered by the Nucleo evaluation board mini USB connector.
When the JP1 jumper is fitted (H in Figure 1: "STEVAL-FKI868V1 evaluation board
features"), the radio section is supplied.
By removing this jumper and connecting a power meter, you can measure the S2-LP
current consumption.
2.2 STEVAL-FKI915V1 evaluation board
The STEVAL-FKI915V1 evaluation board is tuned to work in the 868 MHz and 915 MHz
bands.
The FKI915V1 evaluation board features (see Figure 2: "STEVAL-FKI915V1 evaluation
board features"):
•S2-LP (A)
•Skyworks SE2435L FEM (B)
•High frequency 8 MHz crystal (C)
•Two rows with Arduino compliant connectors (D1-D4)
•Balun, matching network and harmonic filter (E)
•SMA connector (F)
•An EEPROM to store the manufacturing data (G)
•A jumper for S2-LP current measurement (H)
•A jumper for Skyworks SE2435L FEM current measurement (I)
•A NUCLEO-L152RE board (please refer to UM1724 for further details) (J)
Figure 2: STEVAL-FKI915V1 evaluation board features

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2.2.1 S2-LP connections
S2-LP signal test points are split across two rows which are Arduino compliant connectors:
CN1, CN3 and CN2, CN4.
The S2-LP shield is connected to the NUCLEO motherboard using the Arduino compliant
connectors.
The connectors and pin names below are used in the STEVAL-FKI915V1 schematic
diagram.
Table 2: S2-LP: FKI915V1 evaluation board pin description
Pin name Pin number Arduino connectors
J5 (D1) J2 (D2) J1 (D3) J6 (D4)
VDD SMPS 1 pin 4
SMPS1 2
SMPS2 3
XOUT 4
XIN 5
SDN 6 pin 8 (SDN)
VDDANASYNTH 7 pin 4
VRSYNTH 8
VREFVCO 9
VDDVCOTX 10 pin 4
TX 11
VRRF 12
RXN 13
RXP 14
VDDRXDIG 15 pin 4
SDO 16 pin 5 (MISO)
SDI 17 pin 4 (MOSI)
SCLK 18 pin 4 (SCK)
CSN 19 pin 2 (CS)
GPIO0 20 pin 1 (GPIO0)
GPIO1 21 pin 3 (GPIO1)
GPIO2 22 pin 4 (GPIO2)
GPIO3 23 pin 6 (GPIO3)
VSMPS3 24
GND 25 pin 7 pins 6 and 7

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2.2.2 STEVAL-FKI915V1 power
The radio frontend is supplied via two different jumpers:
•P3 that supplies the S2-LP (H in Figure 2: "STEVAL-FKI915V1 evaluation board
features")
•P1 that supplies the Skyworks FEM (I in Figure 2: "STEVAL-FKI915V1 evaluation
board features")
The P1 jumper can be fitted in the following ways:
Table 3: STEVAL-FKI915V1 expansion board jumper description
P1
position Comment
2-3 The FEM power supply is connected to the 3.3 V provided by the Nucleo motherboard
1-2 The FEM is supplied by an external voltage that can be provided by P2 connector pin 2.
To measure the radio part power consumption, add the two currents across P1 and P3.
2.3 NUCLEO-L152
2.3.1 Push buttons
The board has one button to reset the microcontroller and another one available for the
application.
2.3.2 LEDs
The available LEDs are:
•LD1: green (Nucleo embedded ST-LINK power on)
•LD2: green (user LED)
•LD3: red (microcontroller power)
2.3.3 Embedded ST-LINK
The ST-LINK/V2-1 programming and debugging tool is integrated in the STM32 Nucleo
boards.
The ST-LINK/V2-1 makes the STM32 Nucleo boards "mbed" enabled.
2.3.4 STM32L152RE microcontroller
The STM32L152RE 64-pin microcontroller on the NUCLEO-L152RE development board is
programmed by the S2-LPS2-LP DK firmware and is used to drive the device through the
GUI or through the library examples.

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2.4 Hardware setup
1
Connect an antenna to the SMA connector
2
Ensure the jumper configuration on the board is correct (see Section 2.1.2: "STEVAL-
FKI868V1 and STEVAL-FKI433V1 power" and Section 2.2.2: "STEVAL-FKI915V1 power")
3
Connect the STM32 Nucleo board to the PC through a USB cable (via CN5
connector)
4
Check the power LED DL4 light is on.

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3 GUI software description
The S2-LP DK GUI included in the software package is a graphical user interface that can
be used to interact with and evaluate the capabilities of the S2-LP device.
You can run this utility by clicking on the S2-LP GUI icon on the desktop or under: Start
→STMicroelectronics →S2-LP DK X.X.X →S2-LP DK
This version of the GUI for S2-LP exclusively targets RF evaluation performance and only
provides the RF test window and the manipulation of the device configuration parameters.
3.1 Installation
To use the S2-LP GUI, make sure you have correctly set up your hardware and software
(S2-LP DK installed).
The firmware image to be programmed is the latest S2LP_CLI_NUCLEO_L1.hex available
in the S2-LP DK SW package in the Binary folder.
In order to download the S2LP_CLI_NUCLEO_L1.hex binary image into the STM32
internal Flash of the STM32 Nucleo board, follow these steps:
•Connect the NUCLEO board to a PC USB port
•Open the S2-LP DK GUI
•Select the COM port associated to the board
•Open Tools → Firmware Upgrade and Browse to select the file
S2LP_CLI_NUCLEO_L1.hex, then press Open and wait for the firmware download.
Alternatively, it is possible to flash the STM32 Nucleo board by dragging and dropping the
S2LP_CLI_NUCLEO_L1.bin binary file into the NODE_L152RE disk drive recognized by
Windows (drive F below).
Figure 3: NODE_L152RE disk drive
3.2 Detailed description
The S2-LP DK GUI can use only one S2-LP DK - MB plus S2-LP RF - DB connected
through a USB cable to a PC. So, it is necessary to run one instance of S2-LP DK - GUI for
each board connected to the PC. Figure 4: "Connection setup 1: 1 PC with S2-LP-DK GUI"
and Figure 5: "Connection setup 2: 2 PCs with S2-LP-DK GUI" show typical connections
with one or two PCs.
Figure 4: Connection setup 1: 1 PC with S2-LP-DK GUI

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Figure 5: Connection setup 2: 2 PCs with S2-LP-DK GUI
During the tests, each S2-LP DK - DB can work as a transmitter (TX) or a receiver (RX).
The TX device is used as a transmitter during the communication tests; the RX device is
used as a receiver during the communication tests. The user can configure the S2-LP DK -
DB as a TX device or RX device and dynamically change this selection before running a
test.
When the user runs the S2-LP DK.exe file, the S2-LP DK - GUI windows appears as shown
below:
Figure 6: S2-LP GUI main window

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3.2.1 Connection panel
At the top of the main window, the user can select the appropriate available COM port from
a drop down list. Once the correct S2-LP COM port is selected, and the open button
clicked, the default configuration of S2-LP is loaded and displayed on the S2-LP DK - GUI.
Click the COM list also to refresh the available COM port list.
Figure 7: Available COM ports
3.2.2 Radio setting panel
The radio setting panel is always shown, informing the user about:
•frequency base;
•modulation;
•data rate;
•frequency deviation;
•channel filter
•output power.
These fields can be changed according to these limits (the values may change slightly
according to the XTAL frequency):
•frequency base
−Middle band: [430 - 470] MHz.
−High band: [860 - 940] MHz.
•modulation:
−2-FSK
−2-GFSK BT 0.5
−2-GFSK BT 1
−4-FSK
−4-GFSK BT 0.5
−4-GFSK BT 1
−ASK
−OOK
•data rate interval: [0.3 - 250] kbps.
•frequency deviation interval: [0.793 - 761] kHz.
•channel filter interval: [1.1 – 769.3] kHz.
•output power interval: [-30.0 14.0] dBm if the Normal (without external PA)
configuration is selected (as for the STEVAL-FKI433V1 or STEVAL-FKI868V1).
•output power interval: [-8.0 27.0] dBm if the PA configuration is selected (as for the
STEVAL-FKI915V1).
Clicking the "Configure radio" button, all the values are sent to the device and then read
and shown.

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Figure 8: S2-LP radio setting
3.2.3 RF test mode
TX CW and TX PN9 commands put the S2-LP in test mode.
Figure 9: RF test mode buttons
Both tests require only one device connected to PC.
3.2.3.1 TX CW test
To start this test mode:
1. select the desired radio settings and load them by clicking the "Configure radio"
button;
2. Click the "TX CW START" button.
Through this test mode, S2-LP transmits a continuous wave (CW) at the selected
frequency and with the selected output power. The user can measure the output signal at
the suitable SMA connector or the TX state current consumption.
The S2-LP stays in TX state until the "TX CW STOP" button is clicked.
To change frequency or output power, stop the running test first and then repeat steps 1
and 2 selecting the desired frequency or output power during step 1.
3.2.3.2 TX PN9 test
To start this test mode:
1. select the desired radio settings and load them by clicking the "Configure radio"
button;
2. click the "TX PN9 START" button.
Through this test mode, S2-LP transmits a PN9 data stream modulated according to the
radio setting.
The user can measure the output signal at the suitable SMA connector or the TX state
current consumption.

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The S2-LP stays in TX state until the "TX PN9 STOP" button is clicked.
To change frequency, output power or modulation scheme, stop the running test first and
then repeat steps 1 and 2 selecting the desired frequency, output power or modulation
scheme during step 1.
3.3 Packet setting
Select "Panel setting" to view the packet configurations available.
First select the desired packet format by pressing one of the radio buttons in the "Packet
format" panel.
The user can choose:
•BASIC
•WMBUS
Each packet format gives different packet setting options.
Figure 10: Basic packet setting panel
3.3.1 Packet setting: BASIC
The options for this packet (default configuration) are:
•Preamble length
•Sync length
•Sync value
•CRC
•FEC
•Data whitening
These fields can be changed according to:

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•Preamble length interval: [1 - 32] bytes.
•Sync length interval: [1 - 4] bytes.
•CRC:
NO CRC.
Poly 0x07 (1 byte).
Poly 0x8005 (2 bytes).
Poly 0x1021 (2 bytes).
Poly 0x864CFB (3 bytes).
Poly 0x04C011BB7 (4 bytes).
The "FEC" and the "Data whitening" can be checked according to the desired setting; if
checked, these features are used during the transmission.
3.3.2 Packet setting: WMBUS
Figure 11: wM-Bus packet setting panel
As shown, selecting wM-Bus, S2-LP uses certain parameters for the desired wM-Bus
submode.
These fields can be changed according to:
•Preamble length interval: [0 - 255] chip sequence (01).
•Postamble length interval: [0 - 255] chip sequence (01).
•wM-Bus submode:
−S1, S2, long header.
−S1m, S2, T2 other to meter.
−T1, T2, meter to other.
−R2 short header.

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3.4 Transmission test
Selecting the "Transmission test" view, the user can access all the available packet tests to
run the transmission.
Figure 12: Transmission test panel
Device role panel
in the "Device role" panel in the left corner, you can set the main role of the device during
transmission (RX and TX).
Data to send panel
The Data to send panel has the hexadecimal value or characters sent by a transmitter. The
maximum length of this field is 255 bytes (GUI limitation) and represents the effective
payload sent. If the HEX check box is selected, the value must be added as 07 08 09 0A
and so on; if the ASCII check box is selected, characters are accepted.
It is also possible to generate a random set of bytes by clicking "Random". In this case, the
random sequence has a length equal to the one set by the payload length field. Since it is
not certain that the randomly generated characters can be converted to ASCII, they are
always represented in HEX format.
RX timeout box
In the RX timeout box, the RX timeout in milliseconds should be set to a value large
enough to receive the full SYNC word (afterwards, the timer is stopped). It can be set to an
approximate value that is larger than the time duration of the preamble and the sync

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lengths. If the value is 0, the RX timeout is infinite and the S2-LP remains in the RX state
until it finds a correct SYNC word.
HEX or ASCII radio buttons
The data received can be displayed in HEX or ASCII format. If ASCII is set and a non-
ASCII character is received, the representation automatically switches to HEX format.
Packet length modes
The S2-LP has the following packet length modes:
•variable - the receiver retrieves the packet length from the packet itself (information
stored by the transmitter in a field). To set the VAR mode (default), the PCKTCTRL2
register bit 0 must be set to 1.
•fixed - needs the receiver to know the length of the expected packet. To set fix mode,
the PCKTCTRL2 register bit must be reset and the GUI disables the length field on the
RX tab. This operation can be easily done by the register table. If the fix mode is
selected, the RX tab in the transmission test will unlock the payload length field,
making it settable by the user.
The Test indicator panel
The Test indicator panel shows all the results about the transmission/reception operations:
the packet number correctly received, the packet lost, the RSSI value, the PER since the
communication start.
•On the right side, there are these controls:
−total packets: sets how many packets the transmitter will send or how many
packets are expected by the receiver (an infinite number of packets can be set if
the value is 0).
−ref timer: sets the period of time during which a packet is sent.
•The test implemented in the GUI firmware defines a cycle in which:
−if the S2-LP is configured as a transmitter, it sends a packet then the device
enters the idle state (ready state) until the period set in the packet rate box
expires; then the cycle is repeated. The duration of this operation depends on the
data rate and the approximate value is reported in the packet duration box.
−if the S2-LP is configured as a receiver, the test works in a similar way: the
device goes into RX state a couple of milliseconds before the transmitter goes
into TX state, then waits for the packet SYNC for the time written in the RX
timeout box. If the packet is received or the RX timeout expires, the S2-LP enters
the idle state (ready) until the period set in the packet rate box expires. During the
first communication, the S2-LP enters the RX state waiting for the first packet
(synchronization packet) with infinite RX timeout.
•The RSSI threshold [dBm] sets the RSSI threshold. For good communication, set an
RSSI threshold in the receiver greater than the RX noise floor.
•The Sense RSSI button can be used to read the RF power in the air according to the
center frequency and the channel filter bandwidth configured. If the Sense RSSI
button is clicked when there is no signal in the air, this feature reveals the RF noise in
the environment.
Low-power checkbox
If the low-power checkbox ischecked, the device idle state is standby instead of ready.