Linx Technologies LT Series User manual

LT Series
Basic Evaluation Kit
User's Guide

Table of Contents
1 Introduction
2 Ordering Information
3 LT Series Transceiver Evaluation Board
3 Board Objects
4 Theory of Operation
4 Using the Kit
5 Development Using the Prototyping Area
6 Range Testing
7 Using the Boards as a Design Reference
8 About Antennas
8 In Closing
9 Online Resources
10 Transceiver Evaluation Board Schematics
Warning: Linx radio frequency ("RF") products may be
used to control machinery or devices remotely, including machinery
or devices that can cause death, bodily injuries, and/or property
damage if improperly or inadvertently triggered, particularly in industrial
settings or other applications implicating life-safety concerns. No Linx
Technologies product is intended for use in any application without
redundancies where the safety of life or property is at risk.
The customers and users of devices and machinery controlled with
RF products must understand and must use all appropriate safety
procedures in connection with the devices, including without limitation,
using appropriate safety procedures to prevent inadvertent triggering by
the user of the device and using appropriate security codes to prevent
triggering of the remote controlled machine or device by users of other
remote controllers.
Do not use this or any Linx product to trigger an action directly
from the data line or RSSI lines without a protocol or encoder/
decoder to validate the data. Without validation, any signal from
another unrelated transmitter in the environment received by the
module could inadvertently trigger the action. This module does not
have data validation built in.
All RF products are susceptible to RF interference that can prevent
communication. RF products without frequency agility or hopping
implemented are more subject to interference. This module does not
have frequency agility built in.
Do not use any Linx product over the limits in this data guide.
Excessive voltage or extended operation at the maximum voltage could
cause product failure. Exceeding the reflow temperature profile could
cause product failure which is not immediately evident.
Do not make any physical or electrical modifications to any Linx
product. This will void the warranty and regulatory and UL certifications
and may cause product failure which is not immediately evident.
!

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1
Introduction
Linx LT Series RF transceiver modules offer a simple, efficient and
cost-effective method of adding wireless communication capabilities to any
product. The Basic Evaluation Kit gives a designer all the tools necessary to
correctly and legally incorporate the LT Series modules into an end product.
The evaluation boards themselves serve several important functions:
• Rapid Module Evaluation: The boards allow the performance of the LT
Series modules to be evaluated quickly in a user’s environment.
• Range Testing: Using the on-board transcoders to generate a duplex
transmission, a pair of evaluation boards can be used to evaluate the
range performance of the modules.
• Design Benchmark: The boards provide a known benchmark against
which the performance of a custom design may be judged.
• Application Development: An onboard prototyping area allows for the
development of custom circuits directly on the evaluation board. All
signal lines are available on a header for easy access.
This kit includes 4 LT Series transceivers*†, 2 MT Series transcoders*, 2
extra PCB-mount RP-SMA connectors, 2 evaluation boards, 2 HD or CW
Series antennas, 4 AAA batteries, and full documentation.
* One part is soldered to each board.
†Two extras are for use on your first prototype boards.
LT Series Basic Evaluation Kit
User's Guide
Revised 3/18/2015
Figure 1: LT Series Basic Evaluation Kit

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2 3
Board Objects
LT Series Transceiver Evaluation Board
1. Battery – 3VDC
2. Power Switch
3. Prototyping Area
4. Breakout Header
5. Confirmation LED
6. Routing Switches
7. LT Series Transceiver Module
8. MT Series Transcoder Chip
9. RP-SMA Antenna Connector
10. LED Button – D2
11. Buzzer Button – D3
12. LED – D0
13. Buzzer – D1
14. LED Button – D0
15. Buzzer Button – D1
16. LED – D2
17. Buzzer – D3
Ordering Information
Ordering Information
Part Number Description
EVAL-***-LT LT Series Basic Evaluation Kit
*** = 315, 418 (Standard), 433MHz
Figure 2: Ordering Information
Figure 3: LT Series Transceiver Evaluation Boards
1
2
34
5
67
8
1
2
34
5
67
8
9
9
10 11
12
13
14 15
16
17
Warning: This product incorporates numerous static-sensitive
components. Always wear an ESD wrist strap and observe proper ESD
handling procedures when working with this device. Failure to observe
this precaution may result in module damage or failure.

–– – –
4 5
Development Using the Prototyping Area
In addition to their evaluation functions, the boards may also be used for
product development. They feature a prototyping area to facilitate the
addition of application-specific circuitry. This area has a connection to VCC
at the bottom and to ground at the top which can be used to power any
added circuitry.
The holes are plated and set at 0.1" on center with a 0.04" diameter,
making it easy to add most industry-standard SIP and DIP packages to the
board.
All of the lines from the transceiver have been wired out to a row of plated
holes on the right side of the prototyping area. Four of the data lines from
the transcoder have also been wired out. This allows for easy access to
connect external circuitry to the modules and the transcoder. Three lines
from the transceiver (DATA, T/R_SEL, and PDN) have been routed to
switches. The switches connect the lines to either the transcoder or the
prototyping area. This allows the transceiver to be conveniently switched
between the transcoder and application circuitry during testing.
Note: If added circuitry requires a higher current than can be provided
by the batteries, the batteries must be removed and the board powered
from an external source.
Theory of Operation
The two transceiver evaluation boards are identical, but they are populated
slightly differently. The MT Series transcoder is both an encoder and a
decoder, with the input or output nature of each line being determined by
how the board is populated. One board has buttons S0 and S1 populated,
making those lines inputs. On the other board, those lines are connected
to the buzzer and LED, respectively. Conversely, the first board has lines
D2 and D3 connected to the buzzer and LED, while the second board has
buttons S2 and S3 populated. This allows for bidirectional remote control.
To use the kit, simply attach the antennas, turn on the power, and press
one or both of the buttons on a board. When S0 or S2 is pressed, the
buzzer sounds; when S1 or S3 is pressed, the LED turns on.
Both boards have a confirmation LED. When one transcoder sends a
command to the second transcoder, the second transcoder sends a
confirmation back to the first transcoder indicating that the command was
received and the action performed. When the first transcoder receives the
confirmation, it turns on the CONFIRM LED to indicate this. This feature
offers the ability to range test without needing to be in visual or hearing
range of both boards.
The MT Series Transcoder Data Guide goes into the many features of the
transcoders in detail, but this is the only set-up required for operation of
this kit.
Using the Kit
Using the kit is straightforward. Simply attach the antennas, turn on the
power, and press buttons on one of the boards. When S0 or S2 is pressed,
the LED turns on; when S1 or S3 is pressed, the buzzer sounds. When any
button is pressed, the CONFIRM LED lights up to indicate that the other
side got the command.

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6 7
transceiver’s RSSI voltage with the other transceiver turned off to determine
if ambient interference is present. If this fails to resolve the issue, please
contact Linx technical support.
Using the Boards as a Design Reference
The basic evaluation boards included in this kit are very simple, yet they
illustrate some important techniques that should be incorporated into the
board layout. The module’s mounting pads extend slightly past the edge of
the part. This eases hand assembly and allows for better heat conduction
under the part if rework is necessary. A full ground plane fill is placed on the
bottom of the board. This ground plane serves three important purposes:
First, since a quarter-wave antenna is employed, the ground plane is
critical to serve as a counterpoise (please see Application Note AN-00500
“Antennas: Design, Application, and Performance” for details on how a
ground plane affects antenna function).
Second, a ground plane suppresses the transfer of noise between stages
of a product as well as unintentional radiation of noise into free space.
Third, a ground plane allows for the implementation of a microstrip feed
between the module and the antenna. The term microstrip refers to a PCB
trace running over a ground plane that is designed to serve as a 50-ohm
transmission line. See the LT Series data guide or the calculator available
on our website for details on microstrip calculations.
Range Testing
Several complex mathematical models exist for determining path loss in
many environments. These models vary as the transmitter and receiver are
moved from indoor operation to outdoor operation. Although these models
can provide an estimation of range performance in the field, the most
reliable method is to simply perform range tests using the transmitter and
receiver in the intended operational environment.
Basic range testing can be performed with the transceiver evaluation
boards. To prepare the board for range testing, turn it on by switching the
power switch to the ON position. Pressing S0 or S2 activates the buzzer on
the receiver board, while S1 or S3 activates the LED. The CONFIRM LED
provides an indication that the signal has traveled round trip, so only one
person is needed to conduct range testing.
As the maximum range of the link in an area is approached, it is not
uncommon for the signal to cut in and out as the transmitter moves. This
is normal and can result from other interfering sources or fluctuating signal
levels due to multipath. Multipath results in cancellation of the transmitted
signal as direct and reflected signals arrive at the receiver at differing times
and phases. The areas in which this occurs are commonly called “nulls”
and simply walking a little further usually restores the signal. If this does not
restore the signal, then the maximum effective range of the link has been
reached.
Since the evaluation boards are intended for use by design engineers, they
are not FCC certified. The transmitter section has been set to approximate
legal limits by resistor R9 so that the range test results will approximate the
results from a well-designed, certified product. For applications where Part
15 limits are not applicable or output levels can be legally raised due to
protocol duty cycle, R9 can be changed according to the Output Power vs.
LADJ Resistance graph in the LT Series Transceiver Module Data Guide.
To achieve maximum range, keep objects such as your hand away from
the antenna and ensure that the antenna on the transmitting board has a
clear and unobstructed line-of-sight path to the receiving board. Range
performance is determined by many interdependent factors. If the range
you are able to achieve is significantly less than specified by Linx for the
products you are testing, then there is likely a problem with either the board
or the ambient RF environment in which the board is operating. First, check
the battery, switch positions, and antenna connection. Next, measure the

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8 9
About Antennas
The choice of antennas is one of the most critical and often overlooked
design considerations. The range, performance, and legality of an RF link
are critically dependent upon the type of antenna employed. Linx offers
a variety of antenna styles that can be considered for a design. Included
with your kit are HD Series (315MHz) or CW Series (418MHz and 433MHz)
connectorized whip antennas that should be connected prior to using the
kit. Despite the fact that the antenna is not centered on the board’s ground
plane, it exhibits a VSWR of <1.7 and suitably demonstrates the module’s
best practical performance.
In Closing
Here at Linx, “Wireless Made Simple” is more than just our motto, it is our
commitment. A commitment to the highest caliber of product, service,
and support. That is why, should you have questions or encounter any
difficulties using the evaluation kit, you’ll be glad to know many resources
are available to assist you. First, check carefully for the obvious, then
visit our website at www.linxtechnologies.com or call [phone]
between 8AM and 4PM Pacific Time to speak with an application engineer.
Legal Notice: All Linx kits and modules are designed in keeping with
high engineering standards; however, it is the responsibility of the user to
ensure that the products are operated in a legal and appropriate manner.
The purchaser understands that legal operation may require additional
permits, approvals, or certifications prior to use, depending on the
country of operation.
Online Resources
www.linxtechnologies.com
If you have questions regarding any Linx product and have Internet access,
make www.linxtechnologies.com your first stop. Day or night, the Linx
website gives you instant access to the latest information regarding the
products and services of Linx. It’s all here, including:
• Manual and Software Updates
• Latest News
• Data Guides
• Application Notes
• Knowledgebase
• FCC Information
And much more. Be sure to visit often!
www.antennafactor.com
The Antenna Factor division of Linx offers
a diverse array of antenna styles, many of
which are optimized for use with our RF
modules. From innovative embeddable
antennas to low-cost whips, domes to GPS
antennas, Antenna Factor likely has an
antenna for you, or can design one to meet
your requirements.
Figure 4: Antenna Factor Antennas
by

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10 11
Transceiver Evaluation Board Schematics
GND
S8
VCC
+C1
10uF
GND
VCC
RF 1
GND
2-5
ANT1
CONREVSMA001
GND
VCCGND
R9
750 ohm
VCC
GND
A REF
RSSI
RF
1
GND
2
NC
3
RSSI
4
A REF
5
ANALOG
6DATA 7
T/R SEL 8
PDN 9
GND 10
VCC 11
LADJ 12
U1
TRM-XXX-LT
PDN
TRSEL
DATA
B1
BAT-AAA
R17
200 ohm
D0
green
GND
BZ1
BUZZER
B`
4
C
5
C`
6
GND
7
B
3
A`
2
A
1
E11
F` 12
F13
VCC 14
E` 10
D9
D` 8
U3
CD4069UB HEX INVERTER
C2
0.01uF
R19
100k
R20
10k
GND
BUZZER
LED
D3
D2
D1
D0
VCC
R21
0 ohm
R0
100K
R1
100K
GND
GND
S1
S0
PDN
DATA
TRSEL
A REF
VCC
BUZZER
VCC
R22
0 ohm
R2
100K
R3
100K
GND
GND
S3
S2
R18
0 ohm
VCC
BUZZER
LED
LED
R23
0 ohm
1
2
3
4
5
6
7
8
TS1
Test Strip 1
GND
R13
100K
GND
GNDGND
GND
GND
R12
100k
D3
D2
D1
D0
PDNMT
R7
100K
R6
100K
R4
100K
R5
100K
GND
GND
GND
VCC
R14
100K
R15
200 ohm
VCC
D6
D7
CRT/LRN
ENC_SEL
SER_IO
CONFIRM
TR_PDN
TR_SEL
TR_DATA D0
D1
D2
MODE_IND
BAUD_SEL
LATCH
D3
D4
D5
GND
U2
LICAL-TRC-MT
TRSELMT
DATAMT
D10
LED0805
GND
GND
TRANSCEIVER EVALUATION BOARD TRANSCEIVER EVALUATION BOARD
Power Supply Section
RF Module Section
Header Section
Duplex Range Test Section
RSSI9
S4
SW-SPDT
S5
SW-SPDT
S6
SW-SPDT
PDNMT
TRSELMT
DATAMT
GND
S8
VCC
+C1
10uF
GND
VCC
RF 1
GND
2-5
ANT1
CONREVSMA001
GND
VCCGND
R9
750 ohm
VCC
GND
A REF
RSSI
RF
1
GND
2
NC
3
RSSI
4
A REF
5
ANALOG
6DATA 7
T/R SEL 8
PDN 9
GND 10
VCC 11
LADJ 12
U1
TRM-XXX-LT
PDN
TRSEL
DATA
B1
BAT-AAA R17
200 ohm
D0
green
GND
BZ1
BUZZER
B`
4
C
5
C`
6
GND
7
B
3
A`
2
A
1
E11
F` 12
F13
VCC 14
E` 10
D9
D` 8
U3
CD4069UB HEX INVERTER
C2
0.01uF
R19
100k
R20
10k
GND
BUZZER
LED
D3
D2
D1
D0
VCC
R21
0 ohm
R0
100K
R1
100K
GND
GND
S1
S0
PDN
DATA
TRSEL
A REF
VCC
BUZZER
VCC
R22
0 ohm
R2
100K
R3
100K
GND
GND
S3
S2
R18
0 ohm
VCC
BUZZER
LED
LED
R23
0 ohm
1
2
3
4
5
6
7
8
TS1
Test Strip 1
GND
R13
100K
GND
GNDGND
GND
GND
R12
100k
D3
D2
D1
D0
PDNMT
R7
100K
R6
100K
R4
100K
R5
100K
GND
GND
GND
VCC
R14
100K
R15
200 ohm
VCC
D6
D7
CRT/LRN
ENC_SEL
SER_IO
CONFIRM
TR_PDN
TR_SEL
TR_DATA D0
D1
D2
MODE_IND
BAUD_SEL
LATCH
D3
D4
D5
GND
U2
LICAL-TRC-MT
TRSELMT
DATAMT
D10
LED0805
GND
GND
TRANSCEIVER EVALUATION BOARD TRANSCEIVER EVALUATION BOARD
Power Supply Section
RF Module Section
Header Section
Duplex Range Test Section
RSSI9
S4
SW-SPDT
S5
SW-SPDT
S6
SW-SPDT
PDNMT
TRSELMT
DATAMT
GND
S8
VCC
+C1
10uF
GND
VCC
RF 1
GND
2-5
ANT1
CONREVSMA001
GND
VCCGND
R9
750 ohm
VCC
GND
A REF
RSSI
RF
1
GND
2
NC
3
RSSI
4
A REF
5
ANALOG
6DATA 7
T/R SEL 8
PDN 9
GND 10
VCC 11
LADJ 12
U1
TRM-XXX-LT
PDN
TRSEL
DATA
B1
BAT-AAA R17
200 ohm
D0
green
GND
BZ1
BUZZER
B`
4
C
5
C`
6
GND
7
B
3
A`
2
A
1
E11
F` 12
F13
VCC 14
E` 10
D9
D` 8
U3
CD4069UB HEX INVERTER
C2
0.01uF
R19
100k
R20
10k
GND
BUZZER
LED
D3
D2
D1
D0
VCC
R21
0 ohm
R0
100K
R1
100K
GND
GND
S1
S0
PDN
DATA
TRSEL
A REF
VCC
BUZZER
VCC
R22
0 ohm
R2
100K
R3
100K
GND
GND
S3
S2
R18
0 ohm
VCC
BUZZER
LED
LED
R23
0 ohm
1
2
3
4
5
6
7
8
TS1
Test Strip 1
GND
R13
100K
GND
GNDGND
GND
GND
R12
100k
D3
D2
D1
D0
PDNMT
R7
100K
R6
100K
R4
100K
R5
100K
GND
GND
GND
VCC
R14
100K
R15
200 ohm
VCC
D6
D7
CRT/LRN
ENC_SEL
SER_IO
CONFIRM
TR_PDN
TR_SEL
TR_DATA D0
D1
D2
MODE_IND
BAUD_SEL
LATCH
D3
D4
D5
GND
U2
LICAL-TRC-MT
TRSELMT
DATAMT
D10
LED0805
GND
GND
TRANSCEIVER EVALUATION BOARD TRANSCEIVER EVALUATION BOARD
Power Supply Section
RF Module Section
Header Section
Duplex Range Test Section
RSSI9
S4
SW-SPDT
S5
SW-SPDT
S6
SW-SPDT
PDNMT
TRSELMT
DATAMT
GND
S8
VCC
+C1
10uF
GND
VCC
RF 1
GND
2-5
ANT1
CONREVSMA001
GND
VCCGND
R9
750 ohm
VCC
GND
A REF
RSSI
RF
1
GND
2
NC
3
RSSI
4
A REF
5
ANALOG
6DATA 7
T/R SEL 8
PDN 9
GND 10
VCC 11
LADJ 12
U1
TRM-XXX-LT
PDN
TRSEL
DATA
B1
BAT-AAA
R17
200 ohm
D0
green
GND
BZ1
BUZZER
B`
4
C
5
C`
6
GND
7
B
3
A`
2
A
1
E11
F` 12
F13
VCC 14
E` 10
D9
D` 8
U3
CD4069UB HEX INVERTER
C2
0.01uF
R19
100k
R20
10k
GND
BUZZER
LED
D3
D2
D1
D0
VCC
R21
0 ohm
R0
100K
R1
100K
GND
GND
S1
S0
PDN
DATA
TRSEL
A REF
VCC
BUZZER
VCC
R22
0 ohm
R2
100K
R3
100K
GND
GND
S3
S2
R18
0 ohm
VCC
BUZZER
LED
LED
R23
0 ohm
1
2
3
4
5
6
7
8
TS1
Test Strip 1
GND
R13
100K
GND
GNDGND
GND
GND
R12
100k
D3
D2
D1
D0
PDNMT
R7
100K
R6
100K
R4
100K
R5
100K
GND
GND
GND
VCC
R14
100K
R15
200 ohm
VCC
D6
D7
CRT/LRN
ENC_SEL
SER_IO
CONFIRM
TR_PDN
TR_SEL
TR_DATA D0
D1
D2
MODE_IND
BAUD_SEL
LATCH
D3
D4
D5
GND
U2
LICAL-TRC-MT
TRSELMT
DATAMT
D10
LED0805
GND
GND
TRANSCEIVER EVALUATION BOARD TRANSCEIVER EVALUATION BOARD
Power Supply Section
RF Module Section
Header Section
Duplex Range Test Section
RSSI9
S4
SW-SPDT
S5
SW-SPDT
S6
SW-SPDT
PDNMT
TRSELMT
DATAMT
Figure 5: Power Supply Section
Figure 6: RF Module Section
Figure 7: Header Section
Figure 8: Duplex Range Test Section

Disclaimer
Linx Technologies is continually striving to improve the quality and function of its products. For this reason, we
reserve the right to make changes to our products without notice. The information contained in this Data Guide
is believed to be accurate as of the time of publication. Specifications are based on representative lot samples.
Values may vary from lot-to-lot and are not guaranteed. “Typical” parameters can and do vary over lots and
application. Linx Technologies makes no guarantee, warranty, or representation regarding the suitability of any
product for use in any specific application. It is the customer’s responsibility to verify the suitability of the part for
the intended application. NO LINX PRODUCT IS INTENDED FOR USE IN ANY APPLICATION WHERE THE SAFETY
OF LIFE OR PROPERTY IS AT RISK.
Linx Technologies DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE. IN NO EVENT SHALL LINX TECHNOLOGIES BE LIABLE FOR ANY OF CUSTOMER’S INCIDENTAL OR
CONSEQUENTIAL DAMAGES ARISING IN ANY WAY FROM ANY DEFECTIVE OR NON-CONFORMING PRODUCTS
OR FOR ANY OTHER BREACH OF CONTRACT BY LINX TECHNOLOGIES. The limitations on Linx Technologies’
liability are applicable to any and all claims or theories of recovery asserted by Customer, including, without
limitation, breach of contract, breach of warranty, strict liability, or negligence. Customer assumes all liability
(including, without limitation, liability for injury to person or property, economic loss, or business interruption) for
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Products sold by Linx Technologies to Customer. Under no conditions will Linx Technologies be responsible for
losses arising from the use or failure of the device in any application, other than the repair, replacement, or refund
limited to the original product purchase price. Devices described in this publication may contain proprietary,
patented, or copyrighted techniques, components, or materials. Under no circumstances shall any user be
conveyed any license or right to the use or ownership of such items.
©2015 Linx Technologies. All rights reserved.
The stylized Linx logo, Wireless Made Simple, WiSE, CipherLinx and the stylized CL logo are trademarks of Linx Technologies.
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