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DEMO90121DA
RFID Door Access Demo User Manual
Features and Benefits
Applications
‰
‰
‰
‰
‰ Short range contacless Door Access Control
‰ Short range RFID terminal
Battery operated stand alone RFID reader
10$ BOM cost target
Low power consumption (400uA average)
Optimized form factor for easy integration
Ordering Information
Part No.
DEMO90121DA
Description
RFID Door Access Demonstrator
1 Scope
The DEMO90121DA is a turnkey contactless
door access example based on the RFID
transceiver IC MLX90121. Once set up, it
detects and reads ISO14443A cards and is
capable through software configuration of
lighting a red or a green LED.
As a stand alone application running on
battery, the current consumption is optimized,
taking into account a fast response time. The
form factor is minimized to demonstrate the
high level of integration allowed by the
MLX90121. The bill of material of
DEMO90121DA targets a cost of 10$ per
component set for 1000 modules.
This document includes fast start instructions,
describes the performance of the demo and
explains its hardware and software. One can
see this document as a starting point for
building their own access control system by
adapting the functions and performances to
their specific requirements.
2 Related Melexis Products
MLX90121 – 13.56MHz transceiver
Complete schematics, bill of material and
layout are annexed to this document allowing
a fast start for development. Source code of
the firmware is based on the FW90121 library
and is available on the CD ROM provided
with the DEMO90121DA. This device is
based on ISO14443A RFID standard, but the
software library makes it is easy to adapt the
firmware to use another ISO protocol.
Note 1: The device is for demonstration purpose and has not been tested for compliance with FCC, ETSI or any other regulations.
Note 2: The MLX90121 is limited to positive temperatures in the ISO14443A mode. Therefore and without any changes, this
demonstrator is suitable for indoor applications. Should you require outdoor operations, you may modify its firmware to use the
demonstrator with ISO14443B cards.
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Table of Contents
1 Scope ...................................................................................................................................................... 1
2 Related Melexis Products ................................................................................................................... 1
3 Introduction ........................................................................................................................................... 3
4 Box Content........................................................................................................................................... 3
5 Connections .......................................................................................................................................... 5
6 Working principle ................................................................................................................................. 5
7 Functions and use................................................................................................................................ 5
7.1 System initialization .......................................................................................................................... 5
7.2 Opening the door............................................................................................................................... 5
7.3 Transfer access right ........................................................................................................................ 5
8 Observations ......................................................................................................................................... 6
9 Hardware ................................................................................................................................................ 7
9.1 General............................................................................................................................................... 7
9.2 RF part ............................................................................................................................................... 7
9.3 Microcontroller .................................................................................................................................. 8
9.4 Power................................................................................................................................................. 9
9.5 Clock.................................................................................................................................................. 9
9.6 Interface........................................................................................................................................... 10
10 Firmware ............................................................................................................................................ 11
10.1 Structure ........................................................................................................................................ 11
10.2 Practical information..................................................................................................................... 15
11 Power consumption......................................................................................................................... 15
12 Conclusion......................................................................................................................................... 16
13 Annexes.............................................................................................................................................. 17
14 Disclaimer .......................................................................................................................................... 20
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3 Introduction
You purchased a DEMO90121DA. Thanks for choosing Melexis. This demonstrator is a contactless door
access solution based on the MLX90121. This document contains the instructions to use and evaluate the
functions and the performances of this demonstrator.
All the necessary hardware is provided in the packaging box and the microcontroller on-board is already
programmed with the same firmware as the one present on the CD. All that you need to do is to plug the
cables, and then to check visually the LED status when one or more of the tag cards are close to the
antenna.
Should you want to start a development based on this demonstrator, you will find in this document and on the
CD all information like schematics, board layout, list of component, firmware source (C code) and the related
application note. Please note that all this material is provided to support the use of the related Melexis
product. Duplication, circulation or storage on data carriers in any manner for any other type of use are not
authorized by Melexis unless specific agreement.
4 Box Content
You will find in the box the following components.
• 1 RFID reader board
LED D3
Battery cable connector
Antenna connector
LED D4
Figure 1 RFID reader board. Top side
•
1 antenna board
Antenna connector
Figure 2 Antenna ANT2_0
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•
3 tag cards
Figure 3 ISO14443A tag cards
•
9V battery and battery cable
Battery
Battery connector
Connector to
reader board
Figure 4 The 9V battery and the power supply cable
•
•
•
1 CD with the firmware and documentation
The delivered CD contains the complete documentation of the hardware and firmware for
DEMO90121DA, User Manual, Datasheet MLX90121, Source Code of the firmware (written in C,
flavor AVR gcc), Hex file of the firmware, Schematics of the board (ORCAD 9.2 file), Layout of the
board (GERBER files), Bill of materials of the board
1 User Manual (on paper) - this document
1 Box Content (on paper)
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5 Connections
The first step is to connect the component. Connect antenna board to the RFID reader board (3 pin
connector). Then, connect battery cable to the RFID reader board (2 pin connector). Plug the battery to the
battery connector of the cable.
6 Working principle
Once connected, this demonstrator allows the use of several functions which are generally used in RFID door
access devices. Its principle is based on the unique identification number (UID) of ISO14443A tags.
The demonstrator is able to store several UID. All cards which UID number is stored in the device can open
the door. Each card is associated with a specific access privilege, Master Key or Valid Key. The highest card
level (Master Key) which is unique (It can be only one card with Mater key privilege) can transfer its rights to
open the door to a card which acquire by this way the second access level (Valid Key).
The device can be re-initialized. By this way, one can change the card with the Master Key privilege and
remove all other card from the Valid Key card list. When powering on the module or resetting it through its
reset button, the module starts an initialisation phase:
• If no tag is present in the reading range of the antenna, nothing changes in the configuration. The
UIDs previously stored in the memory are kept.
• If one tag is present, the device will read its UID, store it and associate it with the Master Key
privilege and delete other UID from memory.
• If two or more tags are present, nothing changes in the configuration. The UIDs previously stored in
the memory are kept.
As this device could be an example for battery powered access control system, the power consumption was
optimized. Therefore, the device is running in low power mode the main part of the time and switch on its tag
detection function for few instant. In absence of tag, the device enters back in low power. In the opposite
case, it starts an RFID communication and the door access function.
7 Functions and use
7.1 System initialization
Place a card on the antenna. Press BUTTON1 (reset) of the DEMO90121DA and check that the LEDs D3
and afterwards D2 start to blink rapidly (microcontroller registers tag card nr.1 as master card)
7.2 Opening the door
The device executes this operation in 3 steps; tag detection, opening ISO14443A communication, reading
and checking the UID. Approach any kind of card near to the antenna. LEDs D2 and D3 will be on together
indicating that a tag is detected. If this card is compliant to ISO14443A, then D2 will blink alone once. In the
opposite case, nothing more happens. If this card has any access privilege (Master or Valid Key) then D3 will
blink alone once, meaning that the card is recognized as valid card. In other case, nothing more happens.
7.3 Transfer access right
Put the card with the Master Key privilege (card A) together with another card (card B) close to the antenna.
LEDs D2 and D3 will be on together (tag detected), then D2 alone will blink two times (two ISO14443A cards
are detected), then D3 alone will blink two times (two valid codes are stored in microcontroller memory). This
means that right to open the door is transferred from the card A to the card B. The card B UID is added as
Valid Key card one.
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8 Observations
1. Reading range of the DEMO90121DA is about 10cm.
2. Tag detection is made by change of the antenna field load compared to previous cycle (one cycle is
about 300ms or longer). Therefore, the LEDs D2 and D3 blinking once together indicating in this way the
field change. It could occur that approaching objects to the antenna generates a tag detection indication
3. When one or more ISO14443 tag cards are already in the field, just after the tag detection indication D2
will blink indicating how many cards it detected: once if only one card, twice if it detected two cards, etc.
4. In order to reduce a too strong coupling between tag cards, fan them a little when approaching two or
more to the antenna.
5. The valid tag codes are stored in the non-volatile memory of the microcontroller of the DEMO90121DA,
so after a power-off the codes are not lost.
6. The average current consumption is ~0.4mA (no change of the antenna load).
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9 Hardware
9.1 General
The DEMO90121DA is built around the MLX90121 RFID transceiver front-end and the 8bit microcontroller
Atmel ATMega8. The MLX90121 handles the air interface in transmission and in reception. It drives the
antenna through its Class E power driver in order to generate the HF magnetic field and modulation
according to the protocol and command generated by the microcontroller. It demodulates the answer from the
tag and provides digital signals to the microcontroller. The ATMega8 runs the protocol and the application
software. The board has three interfaces, one for the door opening mecanism, a SPI connection for the uC
programmation, and a debug connector. It embeds a reset button, clock and power management functions
and can be powered from a battery.
9.2 RF part
Emission
The MLX90121 integrates a class E driver capable of, providing up to 200mW to the antenna. The Class E
driver (TX pin) is connected to the antenna through a resonant load and an adapter circuit. In order to give
users the choice to connect to a variety of different antennas, the transceiver output is matched to 50ȍ
impedance. The adaptation impedance is composed by L2, C6 (resonant load), CV2 , C8, L4, L3, C10, CV1
(impedance adaptor). In order to get the best performance, it is necessary to tune the adaptation circuit. The
tuning operation starts by adjusting CV2 to get the maximum amplitude. Once CV2 is fixed, the adjustment of
CV1 can be done. Any 13.56MHz antenna matched to 50ȍ can be used. However, care should be taken for
its quality factor, which has to be between 10 and 25. In case antennas with other than 50ȍ impedance the
capacitor C9 is used to match the output. Tuning of the antenna has to be done when placed in it’s final
position because close proximity to metallic parts, including wires can cause changes from its characteristics
in free-air. For some tips in building the antenna see 13.56MHz RFID systems and antennas design guide.
L1
BLM31AJ601SN1
C6
C7
+
5V
C1
L2
47pF
100nF
4.7uF/Tantal
1.2uH
GND _TX
R1
1
CV2
2
2K2
2.8-12.5pF
5V
C8
L4
U2
MLX90121
BLM31AJ601SN 1
L3
L5
C ON2
680nH
3
2
1
6.8uH
1
15pF
C9
xxpF
C V1
5.5-50pF
C10
150pF(130pF)
2
R2
1
Antenna
2
10E
GND_TX
5
C12
6
220pF
2
1
4
GND _TX
CLK13M
TP1
3
7
R3
100k
Gnd
1
Close to
Antenna
connector
8
GND_uC
9
GND_TX
RTB
GND_TX
10
VDD1
TX
MOD
RX
VSS3
NC
VSS1
VDD3
XOUT
DSY NC
XIN
VSS2
XBU F
CK
MODE
DIN
NC
VDD2
RTB
DOUT
20
19
18
R SSI
GND_RX
17
16
D SYNC
15
CK
14
MODE
13
D IN
C11
100nF
GND_RX
12
11
5V
D OUT
C13
100nF
Close to pin 7 of
MLX90121
TAG Reader MLX90121
GND_uC
Figure 5 . MLX90121 transceiver block.
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Reception
The reception is done through the R1 resistor which connects the receiver part of the MLX90121 to the
antenna. It’s value can vary from 1kȍ up to 4.7kȍ depending in the back modulation amplitude and the
reading distance. In this example 2.2kȍ gives the best compromise. Special care must be taken when using
other values. If R1 is too big the DC bias voltage and the back modulation signal seen by the receiver are not
enough for correct reception. If R1 is too small the DC bias voltage saturates the receiver input.
Modulation depth
The 10ȍ resistor R2 fixes the 10% modulation index for the ISO14443B communication. When using
ISO14443A cards, the R1 resistor is bypassed by the internal modulation transistor. In case of OOK is used,
resistor can be kept here or not mounted.
9.3 Microcontroller
Connection to MLX90121
The microcontroller controls the MLX90121, manages the clock signals and interfaces the RFID function to
the application, i.e the door lock mechanism. Port D is used to connect the MLX90121 through the signals
CK, DSYNC, DOUT, DIN, RTB and MODE.
DOUT
DSYNC
RST
Y1
2
C 16
100nF
13.56MHZ
C19
C 20
22pF
GND_uC
22pF
2
RSSI
C 17
10nF
C 18
100nF
1
R11
100k
RSSI_f il
C15
10nF
GND _ADC
GND_ADC
GN D_AD C
GND_AD C
GN D_uC
GND_uC
1
R15
10M
24
23
22
21
20
19
18
17
DIN
RTB
MODE
SCK
MISO
MOSI
uC (ADC, memory, serial interface)
TP3
1
1
R 12
100
PD 3
PC1
PD 4
PC0
GND
ADC7
$7 PHJD GND
VC C
GND ATmega8-16AU AREF
VC C
ADC6
PB6
AVC C
PB7
PB5
BLM31AJ601SN 1
1
2
3
4
5
6
7
8
CK
2
GND_uC
L6
PD 5
PD 6
PD 7
PB0
PB1
PB2
PB3
PB4
5V
22nF
CLK13M
PD2
PD1
PD0
PC6
PC5
PC4
PC3
PC2
U3
9
10
11
12
13
14
15
16
C21
32
31
30
29
28
27
26
25
1
10M
5V
Limiter2
Limiter1
R16
2
Gnd
Good_Card
Bad_C ard
LockMotor
GND_ADC
Figure 6. Microcontroller block.
Clock
A 13.56MHz quartz crystal oscillator is connected between PB6 and PB7 for the generation of the clock. The
resistor R12 is used to attenuate the fast transients generated by the clock connection between MLX90121
and ATMega8.
Wakeup Cycles
In order to reduce the power consumption, the microcontroller alternates sleep and wakeup modes. This
cycle is generated by means of a RC circuit composed of R16 and C21 connected on PD3. The time constant
given by the RC enables an interrupt (INT) after about 280ms. The precision is given by the tolerances of
R16 and C21.
Programming and development
The microcontroller can be programmed onboard using the SPI interface. This serial interface associated with
adequate hardware and software allows read and write access to all memory blocks of the microcontroller.
This is useful for firmware updates or changes in case of adaptation to specific requirement.
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Code size
The firmware used in the DEMO90121DA requires 5.2KBytes of program FLASH of the ATMega8. The
microcontroller ATMega8 can be substituted by other pin-compatible ATMEL models, with different
characteristics and prices.
9.4 Power
The DEMO90121DA embeds a 5V regulator and therefore requires at minimum a 6V DC voltage supply. A
diode is used after the power connector to protect the board against reverse voltage.
U1
D1
XC62FP5002P (SOT-89)
C3
C2
10uF/Tantal
100nF
OUT
IN
2
GND
3
1
5V
2
30BQ060
C4
100nF
C5
10uF/Tantal
CON1
1
2
1
Supply
Edge of the
board
Soldered on a free PCB area
of at least 1cm2 (filled with
vias)
Supply
Figure 7 Voltage regulator 5V
The MLX90121 has three sets of supply pins (power and ground) corresponding to its three main blocks: the
digital block, the transmitter block and the receiver block. It is important to separate carefully the supply lines
to reduce the noise issues. Therefore, supply pins are connected as follows:
- the digital block supply pins VSS2 and VDD2 respectively to the microcontroller digital ground and
directly to the main +5V;
- the transmiter supply pins to the TX ground plane (VSS1) and the VDD1 insulated from the main +5V
by a filtering circuit (L1, C7 and C1);
- the receiver supply pins to the RX ground plane (VSS3) and VDD3 to the main +5V through another
filter (L5, C11).
The reference clock block of the MLX90121 is internally connected to the transmiter block, so the
components at pins XIN, XOUT should be placed on the same ground plane (GND_TX).
The microcontroller has two different sets of supply pins, the digital supply (GND_uC and the main +5V) and
the analog one for the ADC, (GDN_ADC and AVCC pin) supplied from the main 5V through a filter (L6, C18).
The microcontroller is awake about 0.98% of the time, and the transmitter 0.25% of the time. The measured
average supply current is below 0.41mA.
The two layer PCB has several ground planes that are connected one to each other by shunts that can be
substituted by some small value resistors (0805 case) in order to reduce noise propagation between the
different functional blocks:
9.5 Clock
The unique clock source reference is one quartz resonator of 13.56MHz connected to the microcontroller. In
order to reduce the component count and the bill of material, the Xtal is shared and the clock output PB7
from the microcontroller is fed to the clock input XIN of the transceiver.
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9.6 Interface
There are additional components that interface the microcontroller to the ’external world’: An SPI interface
which can be used for microcontroller programming, a reset switch for initialization of the system, a debug
connector for the developer to verify the firmware changes and the functional interface composed of 2 LEDs ,
2 digital level inputs for two position sensors (Limiter1 and Limiter2) and one low power digital level output
(LockMotor).
R4
2
1 CH_RST
1K
R5
2
1 CH_MOSI
MOSI
J1
CH_MOSI
5V
1K
R6
2
1 CH_MISO
MISO
2
CH _RST
CH _SCK
CH _MISO
2
4
6
Downloader
100
R7
SCK
1
3
5
female
R ST
GND _uC
1 CH_SCK
1K
Serial Interface for uC
Limiter2
1K
R10
1
2
2
R9
8K2
DoorMechanism
Edge of the
board
3
1
BUTTON1
D2
BAS16
1
Limiter1
1
4
3
2
1
R8
2
5V
CON3
LockMotor
RST
1 3
1K
C14
100nF
GND _uC
11
R 14
11
R13
GN D_uC
uC reset circuit
1K
2
Bad_Card
1K
2
Good_Card
Button_Reset
Edge of the
board
J2
D3
D4
GND_uC
LED R
2
2
LED G
GN D_uC
CK
MODE
DIN
DOUT
RTB
DSY NC
1
2
3
4
5
6
7
TP_90121dig
GND_uC
Door Mechanism Signals
debug connector
Figure 8 Microcontroller interface to 'external' world
Developers should add an adequate power buffer to be able to drive the door-lock motor or electromagnet.
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10 Firmware
10.1 Structure
The firmware developed for the DEMO90121DA provides master tag programming, anticollision handling
and tag detection as the basic service functions of the door lock application. The flowchart below shows the
main structure of the firmware:
Figure 9 Main flowchart of the DEMO90121DA firmware
After power-on or reset the microcontroller sends a read command to the first tag in the field and stores its ID
in memory. This will become the ID of the master tag for the application. In the event of absence of tag in the
field, the codes previously stored remain valid, including the master one.
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Once done, the firmware enters in its main loop. The RSSI level is measured and compared to the reference
stored in the microcontroller memory in order to detect the presence of a tag in the field. Without any tag, the
system will enter into sleep mode for the period defined by the RC circuit connected on PD3. If a tag is in the
field, it starts an inventory according to ISO14443A protocol (see Figure 10) and reads all the IDs
(identification codes) answering to its requests. (See Figure 9)
Figure 10 Reading the tag codes in the field
If only one valid tag is in the field the microcontroller sends the command to open the door. If there are
several valid tags in the field but not the master tag , they will be ignored and the door will not be opened.
(See Figure 9)
If the master tag is detected together with other tags (ISO14443A), the firmware registers all codes as valid,
and will reset all previous valid ones. In order to prevent valid codes redefinition by error, this registering is
conditioned by the state of the two limiters: door-lock should be opened and door handle pushed. If only the
master tag is in the field, the list stays as-is, and the command to open the door is sent. (See Figure 9)
In order to reduce the success rate of code-scan hacking devices, the door-lock can be opened in the
presence of only one valid tag in the field. This applies to the master tag too. A closed door limit switch
condition restricts the firmware to access the function to open the door, and for only one valid tag present in
the field. (See Figure 9)
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After a hardware reset there is the possibility to clean the list of all valid codes and redefine the master tag
code. (See Figure 11)
Figure 11 Reading the master tag code at reset
Observations:
ƒ The valid tag codes can be up to 12 bytes long (96bits).
ƒ The algorithm can be modified in order to comply with the specific needs of the targeted application.
The long sleep period of about 300ms is hardware based (see Figure 12): a RC circuit connected to pin INT1
(pin 1 of ATMega8) is discharged from VDD towards the input level ‘LOW’ triggering in this way an interrupt
(see Figure 12).
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In order to reduce the power consumption of the device, we use POWER DOWN mode of the microcontroller.
All clocks are stopped and only the watch-dog is running. The watch-dog is reset at the end of the main loop,
and also after long delays.
Figure 12 Sleep 300ms sequence
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10.2 Practical information
The firmware of the DEMO90121DA is based on the FW121 library. (FW90121: Firmware description) This
library provides the ISO15693 and ISO14443 protocol functions as specific commands to control the
MLX90121, address its internal registers, and read/write to the EEPROM of the ATMEL microcontroller. At
power-on or reset, the microcontroller IO ports, timers, ADC, and watch-dog, and the MLX90121 transceiver
registers are configured for the ISO14443A protocol as described in the MLX90121 datasheet.
The firmware was developed using GCC under AVR Studio 4. The firmware can be loaded in the
microcontroller using the SPI interface connected to a STK500, STK300, AVRISP mkII module or similar,
driven by appropriate software (AVR Studio, PonyProg2000, etc). FW_DA21_14A.c and FW_DA21_14A.h
contain the firmware specific gcc code and the functions’ prototypes. HwDefs.h describes the hardware
(input, output pins, etc.). The file FW_DA21_14A.aps is the AVR Studio 4 project file.
11 Power consumption
The DEMO90121DA is built for running on battery power and the current consumption is therefore optimized.
The picture below (Figure 13) shows the typical current consumption variation during one cycle (loop).
Figure 13 Supply current variation (No tag in field)
The average current consumption is about 0.41mA giving 100 days autonomy using a 1000mAh battery. This
value is of course dependant on the number of access events and is deeply impacted by the consumption of
the door lock mecanism. Special care should be taken for the choice of RSSI threshold (dVrssi parameter). If
its value is too small, noise can make the device start inventory attempts without tags in proximity.
&XUUHQWFRQVXPSWLRQYDOXHV
Working phase: parameters
Current
Period
[mA]
[ms]
both microcontroller and MLX90121 in power-down: I1 and t1
0.16
288
microcontroller active and MLX90121 in power-down: I2 and t2
4.6
1.64
wake-up phase of MLX90121 (idle mode) and microcontroller activ: I3 and t3 18.5
0.49
MLX90121 in transmit mode and microcontroller active: I4 and t4
75
0.74
As shown in the table, MLX90121 is in power-down most of the time (t1§288ms). The transmitter is on for
very short time if the RSSI signal didn’t change since last loop, then the microcontroller puts MLX90121 in
power-down. If the RSSI signal changed significantly MLX90121 sends the inventory commands, and is
afterwards put in power-down mode (t4 increases to tens of ms). The microcontroller will continue to check
the inventory results and eventually open the door-lock, or store the new codes in EEPROM.
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Using four alkaline AA batteries to supply the application board DEMO90121DA with 10 actuations
(ISO14443A tag cards passed through the 13.56MHz field) per day, the voltage variation looks like depicted
in Figure 14.
VBat in time
0:00:00
0
24:00:00
48:00:00
72:00:00
96:00:00
120:00:00
144:00: 00
-0.01
-0.02
dV -0.03
-0.04
-0.05
-0.06
hh:mm:ss
Figure 14 Battery voltage variation during a few days
12 Conclusion
The DEMO90121DA is an example of a small, cost effective, and simple control module for door access
based on the Melexis 13.56MHz transceiver MLX90121. It can also be considered as an advanced starting
point for developers who want to build their own system meeting their specific requirements.
The software library FW121 facilitates the software development for MLX90121 transceiver, and the
programmer can use high level commands to communicate with the MLX90121. By this way, they can
concentrate on the management of the microcontroller and the upper level functionality of the application.
References
source files: FW_DA21_14A.h, FW_DA21_14A.c, FW_DA21_14A.aps, HwDefs.h.
schematics: See below
Layout: See below
MLX90121 datasheet
ATMega8 datasheet
FW90121: Firmware description
13.56MHz RFID systems and antennas design guide
390129012103
Rev 002
Page 16 of 20
User Manual
Apr. 2008
U1
3
O UT
4.7uF /Tant al
C3
1.2uH
C2
10uF /Tant al
G ND_TX
100nF
CO N1
2
1
2
1
30BQ060
C4
100nF
1
100nF
2
IN
C1
L2
47pF
D1
XC 62F P5002P (SO T- 89)
5V
GND
+
C7
5V
C5
Supply
Edge of the
board
10uF /Tantal
R1
1
Soldered on a free PCB area
of at least 1cm2 (filled with
vias)
2
CV2
2K2
Supply
2. 8- 12.5pF
MLX90121
L5
CON 2
680nH
3
2
1
6.8uH
1
15pF
C9
xxpF
CV1
5. 5- 50pF
C 10
150pF (130pF)
2
R2
Antenna
1
2
3
4
10E
GND_TX
GND_TX
5
C 12
6
2
1
CLK13M
TP1
220pF
7
R3
100k
Gnd
8
G ND_uC
1
Close to
Antenna
connector
9
GN D_TX
RTB
10
GND _TX
RX
VD D1
VSS3
TX
MOD
NC
VSS1
VDD 3
XOUT
DSYNC
CK
XIN
MODE
VSS2
DIN
XBUF
NC
VDD 2
RTB
DOU T
20
19
RSSI
18
G ND_RX
17
R4
RST
2
TP2
1 CH_RST
Close to
CON1
Gnd
16
DSYNC
15
CK
14
MOD E
C11
100nF
MOSI
1K
R5
2
1 CH_MO SI
MISO
1K
R6
2
1 CH_MI SO
SCK
100
R7
2
1 CH_SCK
GN D_R X
DIN
13
12
5V
11
DOU T
C13
J1
CH_MO SI
5V
1
3
5
female
U2
1
5V
C8
L4
BLM31AJ601SN1
L3
13 Annexes
C6
Schematics
390129012103
Rev 002
L1
BLM31AJ601SN1
CH_RST
CH_SCK
CH_MI SO
2
4
6
Downloader
SHUN T1
2
1
GN D_uC
1ohm
100nF
1K
GN D_TX
C20
22pF
GND _uC
22pF
D IN
R TB
MODE
uC (ADC, memory, serial interface)
D2
BAS16
GND_TX
Butt on_Reset
Edge of the
board
2
SHUN T2
2
1
1ohm
R13
Gnd
Good_Card
Bad_Card
LockMotor
1K
2
Same
D3 horizontal
or vertical
line
GN D_uC
Close to pin 5 of
ATmega8
GND_uC
LED R
CK
MOD E
DIN
DOU T
RTB
DSYNC
G ND_uC
Door Mechanism Signals
SHUN T4
2
1
J2
D4
LED G
GND_uC
GND_ADC
GND_uC
uC reset circuit
R14
GND_ADC
TP3
GND _uC
Bad_Card
11
C15
10nF
1K
2
C18
100nF
GN D_RX
Close to Capa Var
1 2
C14
100nF
G ood_C ar d
SCK
MISO
MOSI
1ohm
BUTTON1
RST
R11
100k
RSSI_f il
C 17
10nF
SHUN T3
2
1
R9
8K2
1K
R SSI
GND _ADC
GND_AD C
G ND_ADC
GND_uC
GN D_uC
1
13.56MHZ
C19
24
23
22
21
20
19
18
17
Door Mechanism
Edge of the
board
2
2
C16
100nF
R15
10M
PC1
PC0
ADC7
GND
AREF
ADC6
AVCC
PB5
11
Y1
PD3
PD4
GND
VCC $ 7PHJD
GND ATmega8- 16AU
VCC
PB6
PB7
2
1
R12
100
1K
R10
1
2
Limit er 2
1
CK
2
GN D_uC
PD2
PD1
PD0
PC6
PC5
PC4
PC3
PC2
1
2
3
4
5
6
7
8
22nF
C LK13M
2
1
2
3
4
5
6
7
1ohm
GND_uC
debug connector
CAGE Code
GND connections
DWG N O
R ev
A3
1.1
MELEXI S Technologies SA
Thur sday, August 09, 2007
Scale
RF 90121DA: 13.56MHz Tag Reader f or door access applicat ions
Sheet
1
of
1
User Manual
Apr. 2008
DEMO90121DA
Size
GN D_ADC
Close to pin 5 of
ATmega8
TP_90121dig
RFID Door Access Demo User Manual
Page 17 of 20
5V
1
1
L6
U3
PD5
PD6
PD7
PB0
PB1
PB2
PB3
PB4
C21
9
10
11
12
13
14
15
16
10M
4
3
2
1
R8
Limit er 1
BLM31AJ601SN1
1
32
31
30
29
28
27
26
25
2
5V
CON3
LockMotor
5V
Limiter2
Limiter1
3
R ST
R 16
2
D OUT
D SYN C
1
TAG Reader MLX90121
Close to pin 4 of
MLX90121
Serial Interface for uC
GND_uC
1
Close to pin 7 of
MLX90121
DEMO90121DA
RFID Door Access Demo User Manual
List of components
1
1
1
1
2
1
2
8
BUTTON1
CON1
CON2
CON3
CV1, CV2
C1
C2, C5
C3,C4,C7,C11,C13,C14,C16,C18
Button_Reset
Supply
Antenna
DoorMechanism
5.5-50pF
4.7uF/Tantal
10uF/Tantal
100nF
Type of
component
button
connector
connector
connector
variable capacitor
tantalum capacitor
tantalum capacitor
capacitor
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
3
1
1
1
1
1
2
4
2
1
3
1
1
4
3
1
1
1
1
C6
C8
C9*
C10
C12
C15
C17
C20,C19
C21
D1
D2
D3
D4
J1
J2*
L1,L5,L6
L2
L3
L4
R1
R2
R3,R11
R4,R5,R7,R8
R12,R6
R9
R10,R13,R14
R15
R16
SHUNT1,SHUNT2,SHUNT3,SHUNT4
TP1,TP2,TP3
U1
U2
U3
Y1
47pF
15pF
0pF**
150pF(130pF)
220pF
1nF
10nF
22pF
22nF
30BQ060
BAS16
LED G 1,8MM
LED R 1,8MM
Downloader
TP_90121dig
BLM31AJ601SN1
1.2uH
680nH
6.8uH
4K7**
10**
100K
1K
100
8K2
1K
10M
10M
0ohm**
Gnd
XC62FP5002P (Torex)
MLX90121 (Melexis)
ATmega8-16AU (Atmel)
13.56MHZ
capacitor
capacitor
capacitor
capacitor
capacitor
capacitor
capacitor
capacitor
capacitor
Schottky diode
low-power diode
LED
LED
connector
connector
EMI filter
inductor
inductor
inductor
resistor
resistor
resistor
resistor
resistor
resistor
resistor
resistor
resistor
resistor
test point
voltage regulator
13MHz transceiver
uC
quartz resonator
Quantity
Reference
* Optional component.
**
Value
390129012103
Rev 002
to
Part
be
Page 18 of 20
adjusted
if
necessary
User Manual
Apr. 2008
DEMO90121DA
RFID Door Access Demo User Manual
Layout
TOP
BOTTOM
390129012103
Rev 002
Page 19 of 20
User Manual
Apr. 2008
DEMO90121DA
RFID Door Access Demo User Manual
14 Disclaimer
Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in its
Term of Sale. Melexis makes no warranty, express, statutory, implied, or by description regarding the
information set forth herein or regarding the freedom of the described devices from patent infringement.
Melexis reserves the right to change specifications and prices at any time and without notice. Therefore, prior
to designing this product into a system, it is necessary to check with Melexis for current information. This
product is intended for use in normal commercial applications. Applications requiring extended temperature
range, unusual environmental requirements, or high reliability applications, such as military, medical lifesupport or life-sustaining equipment are specifically not recommended without additional processing by
Melexis for each application.
The information furnished by Melexis is believed to be correct and accurate. However, Melexis shall not be
liable to recipient or any third party for any damages, including but not limited to personal injury, property
damage, loss of profits, loss of use, interrupt of business or indirect, special incidental or consequential
damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical
data herein. No obligation or liability to recipient or any third party shall arise or flow out of Melexis’ rendering
of technical or other services.
© 2007 Melexis NV. All rights reserved.
For the latest version of this document, go to our website at
www.melexis.com
Or for additional information contact Melexis Direct:
America:
Europe, Africa, Asia:
Asia:
phone: +1 603 223 2362
E-mail: [email protected]
Phone: +32 1367 0495
E-mail: [email protected]
Phone: +32 1367 0495
E-mail: [email protected]
ISO/TS 16949 and ISO14001 Certified
390129012103
Rev 002
Page 20 of 20
User Manual
Apr. 2008