AMS AS3933 User manual

Demo Kit Manual
DN[Document ID]
ams Demo Kit Manual, Confidential
Page 1
[v1-02] 2014-Jul-11
Document Feedback
AS3933
Standard Board
AS3933 DEV SYSTEM

AS3933 Standard Board
ams Demo Kit Manual, Confidential
Page 2
[v1-02] 2014-Jul-11
Document Feedback
Table of Contents
1Introduction .......................................................................................................................... 4
1.1 Kit Content ........................................................................................................................... 4
2Getting Started..................................................................................................................... 4
3Hardware Description........................................................................................................... 4
3.1 AS3933 Demoboard............................................................................................................. 4
3.2 125 kHz Wake-up Transmitter Board................................................................................... 6
4Software Description............................................................................................................ 7
4.1 Installing the GUI.................................................................................................................. 7
4.2 Description of the GUI of the Receiver ................................................................................ 8
4.2.1 Channel Enable.................................................................................................................... 8
4.2.2 Low Power Mode ................................................................................................................. 8
4.2.3 Clock Generator................................................................................................................... 9
4.2.4 Calibrate RC Oscillator ........................................................................................................ 9
4.2.5 Antenna Damper.................................................................................................................. 9
4.2.6 Envelope Detector Time Constant....................................................................................... 9
4.2.7 Data Slicer............................................................................................................................ 9
4.2.8 Comparator Hysteresis ........................................................................................................ 9
4.2.9 Gain Reduction .................................................................................................................... 9
4.2.10 Frequency Detection Tolerance........................................................................................... 9
4.2.11 General Settings ................................................................................................................ 10
4.2.12 Wakeup Pattern (Manchester)........................................................................................... 10
4.2.13 Correlator ...........................................................................................................................10
4.2.14 Automatic Time-Out...........................................................................................................10
4.2.15 Clear Wake ........................................................................................................................ 11
4.2.16 Symbol Rate.......................................................................................................................11
4.2.17 Check Resonance Frequency............................................................................................ 11
4.2.18 Input Capacitor Bank..........................................................................................................11
4.2.19 Artificial Wakeup ................................................................................................................ 11
4.2.20 Clear False Wakeup........................................................................................................... 11
4.2.21 Reset RSSI ........................................................................................................................ 11
4.3 Description of the GUI of the Transmitter..........................................................................12
4.3.1 Duration of the Carrier Burst.............................................................................................. 12
4.3.2 Number of Preamble Symbols........................................................................................... 12
4.3.3 Symbol Rate.......................................................................................................................12

AS3933 Standard Board
ams Demo Kit Manual, Confidential
Page 3
[v1-02] 2014-Jul-11
Document Feedback
4.3.4 Enable Buzzer....................................................................................................................12
4.3.5 Wakeup Pattern (Manchester)........................................................................................... 13
4.3.6 Manchester Pattern Length................................................................................................13
4.3.7 Correlator ...........................................................................................................................13
5Schematics, Layers and BOM ........................................................................................... 14
5.1 AS3933 Demoboard Schematic.........................................................................................14
5.2 AS3933 Demoboard Layout............................................................................................... 15
5.3 AS3933 Demoboard BOM ................................................................................................. 16
5.4 125 kHz Wake-up Transmitter Board Schematics.............................................................17
5.5 125 kHz Wake-up Transmitter Board Layout..................................................................... 17
5.6 125 kHz Wake-up Transmitter Board BOM .......................................................................18
6Ordering & Contact Information .........................................................................................19
7Copyrights & Disclaimer.....................................................................................................20
8Revision Information .......................................................................................................... 21

AS3933 Standard Board
ams Demo Kit Manual, Confidential
Page 4
[v1-02] 2014-Jul-11
Document Feedback
1 Introduction
With the AS3933 Demoboard it is possible to demonstrate the chip’s features as described in the
AS3933 datasheet. The 125kHz Wake-up Transmitter Board is included to offer the user a complete
system for evaluation purposes. This application note describes the operation of the two boards and
gives details on the hardware and software implemented in the demokit.
1.1 Kit Content
The kit comprises
1x 125kHz Wake-up Transmitter Board
1x AS3933 Demoboard
2x CR2032 coin cells
1x USB cable
1x USB stick
2 Getting Started
Connect the +9V DC power supply F to the 125kHz Wake-up Transmitter Board.
Insert the +3V battery at H of the AS3933 Demoboard
Turn on the AS3933 Demoboard via the ON/OFF-Switch C. All LEDs flash up once.
Start transmitting wake-up patterns via AUTO E of PATTERN B.
As soon as the AS3933 Demoboard receives a wake-up pattern the RSSI LEDs flash up for
0.5s and show the momentary received signal strength. At the same time the X, Y, or Z LED
flash up indicating which channel receives the strongest signal.
3 Hardware Description
3.1 AS3933 Demoboard
Figure 1: AS3933 Demoboard Top and Bottom
Figure 2: User Interface Description
Label
Name
Description
Info
A
C
D
E
F
H
G

AS3933 Standard Board
ams Demo Kit Manual, Confidential
Page 5
[v1-02] 2014-Jul-11
Document Feedback
Label
Name
Description
Info
A
BUTTON
Long press (1.5s) tunes
the antenna
Each axis (X,Y, and Z) of the LF antenna can be
tuned exactly to 125kHz. The resonance
frequency of each channel can be read out via the
GUI.
1x short press reads
the false wake-ups
The number of false wake-ups can be read out
and displayed via the RSSI-LEDs.
2x short press (double
click) clears the false
wake-ups
Pressing FALSE WAKEUP twice in quick
succession resets the number of false wake-ups.
Each RSSI-LED lights up shortly.
C
ON/OFF
ON/OFF-Switch
Power on/off the Demoboard. Source (battery or
USB) is automatically detected.
G
USB-
Connector
Mini USB 5-pin
Connector
USB interface for GUI.
H
CR2032
Battery
Battery Holder
Insert CR2032 coin cell here.
Figure 3: Indication LEDs
LED
Color
Info
RSSI
(5 bit)
Red
LEDs
Received Signal Strength Indication. Displays the actual received signal
strength whenever a WAKEUP occurs. When pressing FALSE WAKEUP
these LEDs display the number of false wake-ups that occurred.
X
Red LED
Strongest wake-up signal received on channel 1 (X)
Y
Red LED
Strongest wake-up signal received on channel 2 (Y)
Z
Red LED
Strongest wake-up signal received on channel 3 (Z)
Figure 4: Jumper Description
Jumper
Name
Description
Info
F
IDD
Supply
Current
The supply current of the AS3933 can be measured here. Set
this jumper for normal operation.
D
AS3933 specific outputs
D1
WAKE
Wake Output Interrupt
D2
DAT
Data Output
D3
CL_DAT
Manchester Recovered Clock
E
Microcontroller
interface
The SDI interface from the microcontroller can be replaced by a
proprietary solution
E1
CS
Serial Digital Interface Chip Select
E2
SCL
Serial Digital Interface Clock
E3
SDI
Serial Digital Interface Input

AS3933 Standard Board
ams Demo Kit Manual, Confidential
Page 6
[v1-02] 2014-Jul-11
Document Feedback
Jumper
Name
Description
Info
E4
SDO
Serial Digital Interface Output
E5
GND
Ground (0V)
Note: When the AS3933 Demoboard is connected to the GUI it is necessary to RESET the device by turning the AS3933 off
and on via switch C. Another possibility to prepare the Demoboard for USB connection is to press buttons A and B
simultaneously before connecting the USB cable.
3.2 125 kHz Wake-up Transmitter Board
Figure 5: 125kHz Wake-up Transmitter Board
Figure 6: User Interface Description
Label
Name
Description
Info
A
PATT+DATA
Pattern+Data –
Button
The transmitter continuously sends the wake-up
pattern plus data (01010101).
B
PATT
Single-Pattern –
Button
The transmitter sends a single wake-up pattern.
C
AUTO
Automatic Pattern –
Button
The transmitter sends a wake-up pattern every 1s.
D
STOP
Stop Pattern –
Button
The transmitter stops transmitting.
E
USB-
Connector
Mini USB 5-pin
connector
USB interface for the GUI.
F
Power Supply
+9V/2A DC Power
Supply
Insert main power adapter here.
Figure 7: Indication LEDs/ Buzzer
LEDs
Color
Info
G
Buzzer
The buzzer signals whenever a wake-up pattern is transmitted. This
E
A
B
C
D
F

AS3933 Standard Board
ams Demo Kit Manual, Confidential
Page 7
[v1-02] 2014-Jul-11
Document Feedback
LEDs
Color
Info
feature makes range measurements easier. The buzzer can be disabled
via the GUI.
STANDBY
Red
LED
Transmitter is on stand-by. No wake-up pattern is sent.
Pattern
Red
LED
Wake-up pattern is transmitted.
Pattern+Data
Red
LED
Wake-up pattern plus data is transmitted.
Note: Before connecting the 125kHz Wake-up Transmitter Board to the GUI the transmission of wake-up patterns needs to
be terminated by pressing button D.
4 Software Description
4.1 Installing the GUI
Execute the AS3933_EvalSW.msi
Follow the installation guide
Run the GUI AS3933_EvalSW.exe
Note: Before connecting the 125 kHz Wake-up Transmitter Board to the GUI press button D to stop transmitting wake-up
patterns.

AS3933 Standard Board
ams Demo Kit Manual, Confidential
Page 8
[v1-02] 2014-Jul-11
Document Feedback
4.2 Description of the GUI of the Receiver
Figure 8: Graphical User Interface of the AS3933 Demoboard
All adjustments can be saved via Store Settings in the lower right corner of the Receiver tab. If all
settings should be reset to the default configuration push the button Preset Default. All
configurations that are set by the GUI correspond to the Register Map of the AS3933. The Register
Map can be viewed via View/Register Map (Ctrl+M). All registers can be updated manually via
File/Readout Registers (Ctrl+R) or the update of the registers is done automatically via
File/Automatic Update (Ctrl+U).
Note: A possible firmware update can be done via Help/Firmware Update (Ctrl+F). Load the latest *.bin file and update the
firmware.
4.2.1 Channel Enable
The AS3933 Demoboard has a three dimensional antenna. Each of the three antenna inputs can be
enabled or disabled.
4.2.2 Low Power Mode
The AS3933 features two low power modes, which can be selected here. By default no power
saving mode is enabled which means that all channels are active all the time. For details on the low
power modes please see the AS3933.

AS3933 Standard Board
ams Demo Kit Manual, Confidential
Page 9
[v1-02] 2014-Jul-11
Document Feedback
4.2.3 Clock Generator
The clock source for the AS3933 can be selected here. The AS3933 Demoboard has an on-board
crystal oscillator that is used by default. In case the RC oscillator is used it can be calibrated to
achieve a higher precision.
4.2.4 Calibrate RC Oscillator
The RC oscillator can be calibrated via the microcontroller or the LC antenna.
4.2.5 Antenna Damper
The antenna can be damped in order to limit the range. Therefore a resistor inside the AS3933 is
switched into parallel to the antenna. The value of the resistor can be selected between 1kΩ to
27kΩ.
4.2.6 Envelope Detector Time Constant
The performance of the Demodulator can be optimized according to the bit rate and preamble
length. For a higher bit rate the time constant needs to decrease. Adjust the Envelope Detector’s
time constant according to your symbol rate. The recommended time constants for different symbol
rates are listed in the datasheet.
4.2.7 Data Slicer
There are two possibilities to set the threshold level for the Data Slicer: the dynamic threshold and
the absolute threshold. The absolute threshold is set by selecting the hard threshold enable bit. In
quit environments (no noise sources present) the absolute threshold can be reduced by additionally
setting the hard threshold reduction bit. The dynamic threshold is enabled automatically when the
hard threshold enable bit is not set.
In case the dynamic threshold is enabled the noise immunity of the Data Slicer can be adjusted via
the Data Slicer time constant. Increasing this time constant will result in improved noise immunity
only if the minimum preamble length is also adjusted. Therefore, it is not possible to select a
specific Data Slicer time constant in the GUI but different minimum preamble lengths. The Data
Slicer’s time constant is internally linked to this setting. The recommended minimum preamble
lengths for different Data Slicer time constants are listed in the datasheet.
4.2.8 Comparator Hysteresis
The Data Slicer’s comparator hysteresis can be adjusted between 20mV and 40mV. Furthermore,
the data slicer hysteresis can be active for either only positive edges or for both (positive and
negative) edges.
4.2.9 Gain Reduction
The Gain Reduction of the channel amplifier can be selected between 0dB up to -24dB. When the
setting AGC UP-DOWN is selected the maximum achievable gain is also defined by this setting.
4.2.10Gain Reduction
The Frequency Detection Tolerance can be tighter or more relaxed. For details please see the
datasheet.

AS3933 Standard Board
ams Demo Kit Manual, Confidential
Page 10
[v1-02] 2014-Jul-11
Document Feedback
4.2.11General Settings
Enable sensitivity boost: The channel amplifier gain is boosted to +3dB.
AGC only on carrier burst: The automatic gain control is acting only on the first carrier burst.
AGC UP-DOWN: The automatic gain control is operating in both directions (up and down). At
the beginning the gain of the channel amplifier is set to the maximum and the AGC reduces it
according to the received signal input level. If AGC UP-DOWN is disabled the AGC can only
decrease the gain for the whole duration of the data reception. In this mode the system holds
the RSSI peak.
Mask data before wakeup: During the pattern correlation it is possible to display the data
(received preamble + pattern) on the DAT pin, if this bit is disabled. Otherwise, this will be
masked. In case the user decides to mask the data before the generation of the interrupt on the
pin WAKE, then the data will be displayed only after the generation of the interrupt.
Display clock generation: The clock generator output signal is displayed on CL_DAT pin.
4.2.12Wakeup Pattern (Manchester)
Select the wake-up pattern here. Each field defines 4 bit. If the transmitted pattern matches the
selected pattern, a wake-up interrupt is generated at the WAKE pin. The WAKE pin goes high.
4.2.13Correlator
Enable Correlator: If the Correlator is enabled the chip searches first for the preamble bits and
then for data pattern (Manchester encoded wake-up pattern). Should the pattern correlation be
disabled, the AS3933 goes directly into the data receiving mode.
Enable Manchester decoder: If the Manchester decoder is enabled the data on the DAT pin can
be directly read binary. In addition, the recovered clock is presented on the CL_DAT pin.
Manchester Pattern Length: the Manchester pattern length can be selected between 16bit and
32bit. The possible selection of the wake-up pattern (Manchester) is changed accordingly.
16 bit pattern length: Each field of the wake-up pattern defines 4 bit, which are directly
Manchester encoded.
Example: 9 6 6 9 (Manchester) 1001 0110 0110 1001 (binary, Manchester conform); sum =
16bit
32 bit pattern length: Each field of the wake-up pattern identifies 4 bit, which are hexadecimal
encoded. Each bit defines one Symbol and is converted to Manchester by the microcontroller in
the second step.
Example: 7 B A 5 (Symbol) 0111 1011 1010 0011 (binary) 10010101 01100101 01100110
10100101 (binary Manchester conform); sum = 32 bit
Single pattern: The wakeup pattern is sent as single string.
Double pattern: The wakeup pattern is doubled.
4.2.14Automatic Time-Out
The Automatic Time-Out resets the WAKE pin automatically after a certain time. This time can be
selected between 0ms and 350ms.
4.2.15Clear Wake
The Clear Wake button resets the WAKE pin manually.