Linx Technologies OEM User Manual

OEM Transmitter

Evaluation Kit

User's Guide

Warning: Some customers may want Linx radio frequency (“RF”)

Warning: Linx radio frequency ("RF") products may be

!

!

products to control machinery or devices remotely, including machinery

used to control machinery or devices remotely, including machinery
or devices that can cause death, bodily injuries, and/or property

or devices that can cause death, bodily injuries, and/or property
damage if improperly or inadvertently triggered, particularly in industrial

damage if improperly or inadvertently triggered, particularly in industrial
settings or other applications implicating life-safety concerns (“Life and

settings or other applications implicating life-safety concerns. No Linx
Property Safety Situations”).

Technologies product is intended for use in any application without
redundancies where the safety of life or property is at risk.

NO OEM LINX REMOTE CONTROL OR FUNCTION MODULE
SHOULD EVER BE USED IN LIFE AND PROPERTY SAFETY

The customers and users of devices and machinery controlled with
SITUATIONS. No OEM Linx Remote Control or Function Module

RF products must understand and must use all appropriate safety

should be modified for Life and Property Safety Situations. Such
procedures in connection with the devices, including without limitation,

modification cannot provide sufficient safety and will void the product’s
using appropriate safety procedures to prevent inadvertent triggering by

regulatory certification and warranty.
the user of the device and using appropriate security codes to prevent
Customers may use our (non-Function) Modules, Antenna and

triggering of the remote controlled machine or device by users of other
Connectors as part of other systems in Life Safety Situations, but

remote controllers.
only with necessary and industry appropriate redundancies and

in compliance with applicable safety standards, including without

Do not use this or any Linx product to trigger an action directly

limitation, ANSI and NFPA standards. It is solely the responsibility

from the data line or RSSI lines without a protocol or encoder/

of any Linx customer who uses one or more of these products to
decoder to validate the data. Without validation, any signal from
incorporate appropriate redundancies and safety standards for the Life

another unrelated transmitter in the environment received by the
and Property Safety Situation application.

module could inadvertently trigger the action. This module does not
have data validation built in.

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/
All RF products are susceptible to RF interference that can prevent

decoder to validate the data. Without validation, any signal from

another unrelated transmitter in the environment received by the module

communication. RF products without frequency agility or hopping
could inadvertently trigger the action.

implemented are more subject to interference. This module does not
have frequency agility built in.

All RF products are susceptible to RF interference that can prevent
communication. RF products without frequency agility or hopping

Do not use any Linx product over the limits in this data guide.

implemented are more subject to interference. This module does not
Excessive voltage or extended operation at the maximum voltage could

have a frequency hopping protocol built in.
cause product failure. Exceeding the reflow temperature profile could

cause product failure which is not immediately evident.
Do not use any Linx product over the limits in this data guide.

Excessive voltage or extended operation at the maximum voltage could

Do not make any physical or electrical modifications to any Linx

cause product failure. Exceeding the reflow temperature profile could
product. This will void the warranty and regulatory and UL certifications

cause product failure which is not immediately evident.
and may 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.

Table of Contents

1 Introduction
2 Ordering Information
2 OEM Transmitter Button Assignments
3 DS Series Receiver / Decoder Evaluation Board
4 Theory of Operation
4 Using the Kit
5 Setting the Address
6 Input Interpretation Selection Switches
6 Selecting the Protocol
7 Development Using the Prototyping Area
7 Using the Boards as a Design Reference
8 Range Testing
9 About Antennas
9 In Closing
10 DS Series Decoder Evaluation Board Schematic
11 Resources

OEM Transmitter Basic Evaluation Kit

User's Guide

Figure 1: OEM Transmitter Basic Evaluation Kit

Introduction

Linx OEM RF transmitters offer a simple, efficient and cost-effective method
of adding remote control and command capabilities to any product. The
Basic Evaluation Kit provides a designer all the tools necessary to correctly
incorporate Linx OEM transmitters and receiver modules into a product.
The evaluation board serves several important functions:

• Rapid Evaluation: It allows the performance of the transmitters and
receivers to be evaluated quickly in a user's environment.

• Range Testing: Using the OEM transmitter and the included
development board, a simplex transmission is generated that can be
used to evaluate the range performance of the products.

• Prototype Development: An on-board prototyping area is provided,
which allows for additional circuitry to be placed directly on the board
so that it can act as the first prototype of the product. All of the signals
are available on a breakout header for easy access.

• Design Benchmark: During the design process of your product, the kit
provides a known benchmark against which the performance of your
own design may be judged.

The kit includes 2 OEM transmitters, 2 DS Series encoders / decoders*, 2
LR Series receivers*, 2 PCB-mount RP-SMA connectors*, 1 development
board, 1 CW Series antenna, 2 AAA batteries and full documentation.

*One part is soldered to the board, one extra is for use on the first prototype board

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1

Revised 3/18/2015

Ordering Information

Ordering Information

Part Number Description

EVAL-***-HHCP Compact Handheld Basic Evaluation Kit

EVAL-***-HHLR Long-Range Handheld Basic Evaluation Kit

EVAL-***-KEY# Keyfob Basic Evaluation Kit

*** = 315, 418 (Standard) or 433MHz
# = Number of buttons: 1 to 5

Figure 2: Ordering Information

DS Series Receiver / Decoder Evaluation Board

3

2

10

1

4

5

9

6

11

7

12

8

14

13

OEM Transmitter Button Assignments

D7 D6

D0

D3

D4

D1

D2

D5 D4

D3 D2

D1 D0

CMD-HHCP-***

CMD-KEY#-***

CMD-HHLR-***

Figure 3: OEM Transmitter Button Assignments

Figure 4: DS Series Decoder Evaluation Board

1. Battery – 3VDC (use 2 AAA style batteries)

2. Power Switch

3. Power On Indicator LED

4. Prototyping Area

5. Breakout Header

6. LR Series Receiver Module

7. DS Series Encoder / Decoder

8. Reverse-Polarity SMA Antenna Connector

9. LEDs – D1–D7

10. Buzzer – D0

11. Protocol Selection Switch

12. Data and Address Line Interpretation Configuration Switches

13. Address Configuration DIP Switch

14. Valid Transmission Received LED

– – – –

2

3

Theory of Operation

OEM Transmitters

Linx OEM transmitters are a great way to quickly bring a remote control
product to market. They are fully assembled and certified, eliminating the
need for design, tooling, and certification. Linx can also customize the
transmitters with customer specific art, logos or switch layouts.

The operation of the OEM transmitter is straightforward. When a button(s)
is pressed on the OEM transmitter, the states of D0 to D7 are formatted
into packets by an on-board encoder IC. These encoded packets are sent
to a Linx transmitter that, through the antenna, conveys the data into free
space.

Receiver / Decoder Evaluation Board

The receiver board is powered by two AAA batteries. A Linx LR Series
receiver is used for reception of the transmitted signal. This receiver
provides exceptional sensitivity, allowing the transmitter and receiver to
operate at distances of up to 1,000 feet (depending on TX model and
signal conditions). The data recovered by the receiver is decoded by the
DS Series set as a decoder. If the settings of the 10-position DIP switch on
the receiver board match the address setting of the transmitter, the data
line outputs are updated to match the state of the buttons on the OEM
transmitter. To demonstrate this, one data line on the evaluation board is
used to drive a buzzer while the other lines activate LEDs. This board also
has a prototyping area with all of the receiver and decoder lines brought
out to a header.

Setting the Address

The DS Series encoder and decoder each have ten address lines that must
match in order for the transmitter and receiver to talk to each other. If they
do not match, then the decoder ignores the transmission and takes no
action.

To set the address on the receiver evaluation board, note the A0–A9 labels
on the board and turn the DIP switches on or off as desired. If a switch is
on, the address line is connected to ground. If it is off, then the address line
is pulled high to VCC.

Figure 4: The Evaluation Board Address DIP Switch

The four OEM transmitters have different ways of setting their address
lines. For your convenience, a brief explanation follows; however, the OEM
transmitter manual or Application Note AN-00300 should be referenced for
complete details.

The HHCP and HHLR utilize a ten-position DIP switch that is accessed by
a cover on the back of the remote. The switch numbers match the address
lines with switch number 1 corresponding to A0 and number 10 to A9.

Using the Kit

Using the kit is straightforward. Simply attach the antenna to the board and
install the batteries. Set the address on the transmitter and on the board
to the same settings, turn on the power to the board, and press a button
on the transmitter. When D0 is pressed, the buzzer sounds; when S1–S7
are pressed, the LEDs turn on. When any button (D0–D7) is pressed on the
transmitter, the corresponding decoder output (D0–D7) is active high (VCC)
on the prototyping header.

Note: All switches (address, protocol select and interpretation

configuration) must match on both the transmitter and the decoder /
receiver board.

– – – –

4

The Keyfob has ten internal cut traces numbered 0 to 9 to match A0 to A9.
If the trace is intact, it is connected to ground; when cut, it is floating.

Note: All address switches ON and all switches OFF are not valid

states and are not recognized by the decoder. At least one switch
must be set differently from the rest.

5

Input Interpretation Selection Switches

The DS Series was designed to replace an encoder and decoder from
Holtek. These parts had tri-state lines, so the address and data lines could
be high, low or floating. The DS can only be high or low, so these selection
switches are included for backwards compatibility. In the case of the OEM
transmitters, the switches should be set as follows: D_CFG to 0 or down,
A_CFG0 to 0 or down and A_CFG1 to 1 or up (Figure 5). These lines are
hardwired in the transmitter so must be set on the receiver board to match.
Please see the DS Series data guide for more information on the input line
interpretation.

Figure 5: The Evaluation Board Input Interpretation Selection Switches

Selecting the Protocol

The DS Series encoder / decoder offers two over-the-air protocols:
Holtek and serial. The Holtek selection is used when communicating with
other Holtek devices. This is a legacy protocol that provides backwards
compatibility.

The serial selection offers a much more reliable protocol that offers better
range and response time. The protocol is selected by a switch on the
HHPC and HHLR transmitter and the Protocol Select Switch on the
evaluation board, as shown in Figure 6. The CMD-Key# transmitter does
not support serial protocol. The protocols are not interoperable, so the
switches must be set the same on both sides.

Development Using the Prototyping Area

In addition to evaluation functions, the boards may also be used for
product development. The evaluation board features a prototyping area for
the addition of application-specific circuitry. This area has connections to
VCC at the top and to ground at the bottom that can be used to power any
circuitry that is added.

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.

The holes are plated and set at 0.1" on center with a 0.04" diameter,
accommodating industry-standard SIP and DIP packages. The data line
outputs, Valid Transmission (VT) and the DATA line from the receiver (DIN)
have been wired out to a header row to the right of the prototyping area.
This allows easy access for connection to external circuitry. Data line D0 is
connected to a buzzer, D1 to D7 and VT are connected to LEDs.

Using the Boards as a Design Reference

Since the OEM transmitters are a finished product, most of the designer’s
work will be incorporating the receiver into the end product. The basic
evaluation board included in this kit is very simple, yet illustrates some
important techniques that should be incorporated into the board layout.
The receiver’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).

Figure 6: The Evaluation Board Protocol Selection Switch

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 LR Series receiver data guide or the calculator
available on our website for details on microstrip calculations.

– – – –

6

7

Range Testing

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 usage environment.

Simple range testing can be performed with the transmitter and receiver
evaluation board. To prepare the board for range testing, simply turn it
on by switching the power switch to the ON position. Pressing D0 on the
transmitter activates the buzzer on the receiver board, while D1 activates
the LED.

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.

To achieve maximum range, keep objects such as your hand away from
the antenna and ensure that the antenna on the transmitter has a clear and
unobstructed line-of-sight path to the receiver board. Range performance
is determined by many interdependent factors. If the range you are able to
achieve is significantly less than what is specified for the products being
tested, then there is likely a problem either with the board or the ambient
RF environment in which the board is operating. First, check the battery,
switch positions, address settings, and antenna connection. Next, measure
the receiver's RSSI voltage with the transmitter turned off to determine
if ambient interference is present. If this fails to resolve the issue, please
contact Linx technical support.

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 the kit is a Linx connectorized whip antenna that should be connected
prior to using the kit. Despite the fact the antenna is not centered on the
board’s ground plane, it exhibits an outstanding 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 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 the legal operation may
require additional permits, approvals, or certifications prior to use,
depending on the country and operation.

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8

9

ANT1

DS Series Decoder Evaluation Board Schematic

Resources

B1

D8

R21

620 ohm

POWER GREEN

GND

BAT-HLD-AAA

S2

VCC

GND

2-5

RF

CONREVSMA001

1

14

15

16

ANT

GND

NC1NC2NC3GND4VCC5PDN6RSSI7DATA

U1

GND

GND

NC9NC10NC11NC12NC13NC

8

DIN

RXM-XXX-LR

U2

VCC

1

VALID TXM BLUE

D9

VT

123456789

J1

D0D1D2D3D4D5D6

DIN

VT

A9

28

A9

TE/DIN

DOUT/VTP_SEL

D0D1D2D3D4D5GNDD6D7

123456789

TP11TP2

R1

200 ohm

VCC

A4A5A6A7A8

A4A5A6A7A8

VCC

1011121314

GND

GND

A3

A3

E/D_SEL

GND

D_CFG

GND

10

D7

A0A1A2

15161718192021222324252627

A0A1A2

A_CFG0

A_CFG1

14

VCC

U3

1

R7

100k

HEADER 10

R6 200D2R9 200D3R11 200D4R15 200D5R17 200D6R19 200D7R20 200

D1

D0D1D2D3D4D5D6

D[0..7]

LICAL-EDC-DS001

11F`12F13

E

B`4C5C`6GND

B3A`2A

C1

R12

10k

BZ1

10D9D`8

E`

0.01uF

Support

For technical support, product documentation, application notes, regulatory
guidelines and software updates, visit www.linxtechnologies.com

RF Design Services

7

GND

For customers who need help implementing Linx modules, Linx offers
design services including board layout assistance, programming,
certification advice and packaging design. For more complex RF solutions,
Apex Wireless, a division of Linx Technologies, creates optimized designs

GND

with RF components and firmware selected for the customer’s application.
Call [phone] ([phone] if outside the United States) for
more information.

D7

Antenna Factor Antennas

Linx’s Antenna Factor division has the
industry’s broadest selection of antennas
for a wide variety of applications. For

by

customers with specialized needs, custom
antennas and design services are available along with simulations of
antenna performance to speed development. Learn more at
www.linxtechnologies.com.

VCC

VCC

P_SEL

SW1

VCC

GND

GND

SW2

VCC

D_CFG

A_CFG0

A_CFG1

SW3

SW4

VCC

VCC

GND

GND

P_SEL

A[0..9]

S1

GND

Figure 7: DS Series Decoder Board Schematic

D0D1D2D3D4D5D6

A0A1A2A3A4A5A6A7A8

201918

123

D7

D_CFG

A_CFG0

GND

A9

10 11

A_CFG1

A0A1A2A3A4A5A6A7A8

100k

100k

100k

100k

R4R5R8

R3

R2

VCC

GND

100k

100k

R10

100k

R13

100k

R14

100k

R16

A9

100k

R18

GND

171615

141312

456

789

– – – –

10

11

Linx Technologies

159 Ort Lane

Merlin, OR, US 97532

Phone: [phone]

Fax: [phone]

www.linxtechnologies.com

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
all claims, including claims from third parties, arising from the use of the Products. The Customer will indemnify,
defend, protect, and hold harmless Linx Technologies and its officers, employees, subsidiaries, affiliates,
distributors, and representatives from and against all claims, damages, actions, suits, proceedings, demands,
assessments, adjustments, costs, and expenses incurred by Linx Technologies as a result of or arising from any
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.