WIRELESS MADE SIMPLE
®
HP3 Series Master Development System User’s Guide
ORDERING INFORMATION
PART #
MDEV-900-HP3-PPS-RS232
MDEV-900-HP3-SPS-RS232
MDEV-900-HP3-PPS-USB
MDEV-900-HP3-SPS-USB
DESCRIPTION
HP3 Series Master Development System Pinned - RS-232
HP3 Series Master Development System SMD - RS-232
HP3 Series Master Development System Pinned - USB
HP3 Series Master Development System SMD - USB
INTRODUCTION
The Linx HP3 Series RF modules offer a simple, efficient, and cost-effective method
of adding wireless communication capabilities to any product. The Master
Development System is intended to give a designer all the tools necessary to
correctly and legally incorporate the HP3 Series into an end product. The
development boards themselves serve several important functions:
• Rapid Module Evaluation - The boards allow the performance of the Linx HP3
Series modules to be evaluated quickly in a user’s environment.
• Range Testing - By using the on-board encoders and decoders to generate a
simplex transmission, a pair of development boards can be used to evaluate the
range performance of the modules.
• Design Benchmark - During the design process of your product, the boards
provide a known benchmark against which the performance of your own design
may be judged.
• Application Development - An on-board prototyping area is provided to allow a
designer to develop applications directly on the development board. All signal
lines are available on a header for easy connection to the designer’s circuits.
• Protocol Development - The development system features two types of Host
Interface Modules that allow connection via RS-232 or USB to a PC. Windows-
based demonstration software is also included on CD, which allows for a variety
of tests.
The Master Development System includes 2 development boards, one set up for the
transmitter and the other for the receiver, 2 HP3 Series transmitters*, 2 HP3 Series
receivers*, two CW Series antennas, 2 9V batteries, and full documentation.
*One part is soldered to the board, one extra is for use on your first prototype board.
Revised 8/15/08
HP3 SERIES TRANSMITTER DEVELOPMENT BOARD
4
HP3 SERIES RECEIVER DEVELOPMENT BOARD
7
4
8
9
1
5
6
7
9
8
10
2
11
1
5
6
10
2
12
13
3
11
13
12
3
Figure 1: HP3 Series Transmitter Development Board
Figure 2: HP3 Series Receiver Development Board
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
9V Battery
DC Power Jack
On-Off Switch
Host Interface Header
Prototyping Area
TX Breakout Header
TX Channel Selection Mode Switch
HP3 Series Transmitter
RP-SMA Antenna Connector
TX Channel Selection DIP Switch
LS Series Encoder
Buzzer Button (S3)
Relay Button (S2)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
9V Battery
DC Power Jack
On-Off Switch
Host Interface Header
Prototyping Area
RX Breakout Header
RX Channel Selection Mode Switch
HP3 Series Receiver
RP-SMA Antenna Connector
RX Channel Selection DIP Switch
LS Series Decoder
Relay Output
Buzzer
Page 2
Page 3
GETTING STARTED
After unpacking the development system, attach an antenna to each board and
install the supplied 9V battery. The development boards are now ready for use.
The two development boards are very similar and either board can be populated
with a transmitter or receiver module. The simplex range testing sections of the
boards are populated differently since, in the range testing mode, one board is
intended to serve as a transmitter and the other as a receiver.
All of the module's connections are made available to the designer via the
breakout header (J1). The supplied jumper shunts are intended to be placed
across adjacent pins to control the routing of TX and RX data.
USING THE SIMPLEX ENCODER/DECODER SECTION
The transmitter board features a custom remote-control encoder with two push
buttons and the receiver board features a decoder with a relay output and a
buzzer. When a button is pressed on the transmitter board, the status of both
buttons is captured and encoded into a data stream for transmission. The data
recovered by the receiver is decoded and the decoder's data lines are set to
replicate the status of the encoder, driving either the buzzer or the relay.
To activate this area of the board, the
module data line must be routed to the
encoder / decoder. Configure the
transmitter board for encoding and
transmission by placing a jumper
across TX DATA and ENCODER on
header J1. Configure the receiver
board for reception and decoding by
placing a jumper across RX DATA and
DECODER on header J1.
J1
HOST TX
TX DATA
ENCODER
TX MODE
TX PDN
TX CTS
TX CS2/DATA
TX CS1/CLK
TX CS0
GND
J1
HOST RX
RX DATA
DECODER
RX AUDIO
RX MODE
RX RSSI
RX PDN
RX CS2/DATA
RX CS1/CLK
RX CS0
CHANNEL SELECTION
Parallel Selection
All HP3 models feature eight parallel
CS2
CS1
CS0
Channel
selectable channels. Parallel mode is
0
0
1
0
selected by grounding the module's MODE
0
0
0
1
line (default setting). Mode Switches SW2
0
1
1
2
(TX) and SW3 (RX) have been provided to
allow the developer to easily switch between
0
1
0
3
parallel and serial modes. In parallel mode,
1
0
1
4
channel selection is determined by the logic
1
0
0
5
states of lines CS0, CS1, and CS2, as shown
1
1
1
6
in the adjacent table. DIP switches are used
1
1
0
7
on the development boards to set the
channels. If the switch is set to ON, then the
0 = On/Low
1 = Off/High
pin is connected to ground, otherwise it is
Table 1: Channel Selection Table
pulled up inside the module. The DIP switch
positions on both boards must match in order for the modules to communicate.
Serial Selection
In addition to the parallel mode, PS versions of the HP3 also feature 100 serially
selectable channels. The serial mode is entered when the MODE line is left open
or held high. On the Master Development boards, this is accomplished using the
appropriate Mode Switch; SW2 (TX) or SW3 (RX). In this condition CS1 and CS2
become a synchronous serial port with CS1 serving as the clock line and CS2
serving as the data line. The module is then easily programmed by sending and
latching the binary number (0-100) of the desired channel. The programming
data is supplied externally by the development system user. Often it will originate
from a microcontroller or emulator, which can be located in the prototyping area.
Using HP3 modules in serial mode is straightforward; however, minimum timings
and bit order must be followed. Please see the HP3 Series Data Guides for
these timings.
*IMPORTANT*
The channel selection DIP switch must be in the OFF position in
order for the serial lines to be used, otherwise the signal from the microcontroller
will be shunted to ground. It is recommended that resistors be placed in series
on the data and clock lines to limit current and protect your microcontroller in
case the switches are accidentally turned on.
TX
RX
Once the boards have been
SIMPLEX RANGE TEST
configured, place the receiver board on
JUMPER CONFIGURATION
a flat surface and turn it on. Turn on the
(Factory Default)
transmitter board and press button S3.
You should hear the buzzer on the
Figure 3: Jumper Configuration
receiver board sound. You may now walk away from the receiver to ascertain
the useable range of the link in your environment.
Another simple but often overlooked range-testing method is to hold down or
bridge the buzzer button so that a continuous transmission is made and then
walk with the receiver side for testing.
Button S2 activates the relay on the receiver board. The relay’s SPST contacts
can be connected at J2. Any device up to 5A at 30VDC / 120VAC may be
switched through the relay. Most commonly, an external siren or light would be
connected to aid range testing if the on-board buzzer is not loud enough.
As you near the maximum range of the link in your area, it is not uncommon for
the signal to cut in and out as you move. This is normal and can result from other
interfering sources or fluctuating signal levels due to multipath effects. This
results in cancellation of the transmitted signal as direct and reflected signals
arrive at the receiver at differient times and phases. The areas in which this
occurs are commonly called “nulls” and simply walking a little farther will often
restore the signal.
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 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 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.
Page 5
Page 4
HOST INTERFACE MODULE
The HP3 Master Development System features
a Host Interface socket, which allows the use of
two different PC interface modules. The first is a
USB interface module that uses a standard USB
cable (not included) to connect to a PC’s USB
port or a USB hub. The second type of module
is a RS-232 interface module that can be
connected to a standard serial COM port on a
PC using a straight-through 9-pin extension
cable (not included). The evaluation board is
considered a DCE device and as such is
designed to be connected using a straight-thru
serial extension cable. Do not use a null-modem
cable as the boards will not function.
THE PROTOTYPING AREA
A designer wishing to use the development board for product prototyping may
route the necessary signals from the development board's breakout header to
the prototyping area and then use this to build the custom circuitry.
J1 is a wire-wrap header that is provided as an easy access point to the module's
signals. The header pins extend through the board to allow wire attachment on
the back of the board.
USB Interface Module
Regulated power connections are available on the buses labeled "GND" and
"+5VDC". The board also has a DC power jack to allow powering from an
external power supply rather than with the battery. This jack accepts a 5.5mm
plug with the tip ground and the outer shell 7-16VDC positive supply.
NOTE: The on-board 5-volt regulator has approximately 500mA of headroom
available for user's circuitry. If additional current capacity is required, the user
must add an additional regulator to the prototyping area or power the board from
an external supply.
Ground Bus
To install, select the module to be used and then
line up the pins on the module with the headers
on the board. Verify that the pin one polarity
marks on the board and on the Host Interface
RS232 Interface Module
Module match. The USB jack or the D-sub
connector should face away from the board.
Figure 4: Host Interface Modules
Press firmly on the module so that it slides fully
into the header.
The development system may be prepared
J1
J1
for host operation with the supplied Linx
HOST RX
HOST TX
RX DATA
TX DATA
software by setting the jumpers on the
DECODER
ENCODER
header as shown in the adjacent figure. This
RX AUDIO
TX MODE
RX MODE
TX PDN
routes the module's data lines to the Host
RX RSSI
TX CTS
Interface Module. Despite being electrically
RX PDN
TX CS2/DATA
RX CS2/DATA
TX CS1/CLK
interfaced, appropriate protocol must be
RX CS1/CLK
TX CS0
employed to ensure reliable and error-free
RX CS0
GND
data transfer since the HP3 Series modules
TX
RX
do not encode or packetize the data in any
HOST MODE JUMPER
manner. It is important to understand that
CONFIGURATION
the development boards are transparent;
that is, the user's software is entirely
Figure 5: Jumper Configuration
responsible for controlling the timing and
error correction aspects of the link. The evaluation boards have no provision to
check or qualify the incoming data. When designing a protocol to transfer data
across a wireless link, it is very important to remember that interference is
inevitable. The protocol must support error detection and correction if it is to be
successful. A correctly designed protocol will provide optimum performance and
throughput for product-specific applications while taking into account the timing
and data-rate requirements of the module. For further information on protocol
considerations please refer to Application Note AN-00160.
If the designer needs to develop protocols using a physical implementation other
than an RS-232 or USB interface, the designer can build the custom interface
circuitry in the prototyping area and route the module's data signals from the
header to the prototyping area.
Page 6
Regulator
+5 Volt Bus
Figure 6: The Prototyping Area
Page 7
MASTER DEVELOPMENT SOFTWARE
The development system is supplied
with Windows-based software that
facilitates communication with the
development boards through the Host
Interface Module. This software allows
for testing and illustrates basic
implementation of the modules as a
wireless serial link. The user selects
either a USB or RS232 connection and
whether the connected board is the
transmitter or receiver. The user can
Figure 7: Master Development Software
then send text, ASCII characters, and even a picture. Documentation for the
software may be found by going to the 'Help' menu then 'Help File'.
Terminal emulation programs, such as HyperTerminal, do not provide error
correction; therefore, bit errors or data line hashing will be displayed as random
characters. Some form of error detection should be employed when developing
a protocol for wireless environments (please see Application Note AN-00160).
ONLINE RESOURCES
®
www.linxtechnologies.com
•
•
•
•
•
Latest News
Data Guides
Application Notes
Knowledgebase
Software Updates
USING THE BOARDS AS A DESIGN REFERENCE
The master development boards included in this kit are very simple, yet they
illustrate some important techniques that you may wish to incorporate into your
own board layout. You will observe that the HP3 mounting pads (SMD version)
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. Next, observe
the use of a full ground plane fill on the lower side of the board. This ground
plane serves three important purposes:
First, since a 1/4-wave antenna is employed, the ground plane is critical to serve
as a counterpoise (you may wish to read Application Note AN-00500 Antennas:
Design, Application, and Performance for additional details on how a ground
plane affects antenna function).
Second, a ground plane will suppress 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 to 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 between the module and
the antenna. A microstrip is implemented on this evaluation board. If you are
unfamiliar with microstrip calculations, you may wish to refer to the HP3 Series
Data Guides or the calculator available on the Linx Technologies website.
If you have questions regarding any Linx product and have Internet access,
make www.linxtechnologies.com your first stop. Our website is organized in an
intuitive format to immediately give you the answers you need. 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: manual and software updates,
application notes, a comprehensive 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
Yagis, and even GPS, Antenna Factor
likely has an antenna for you, or can
design one to meet your requirements.
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 you may wish to consider for your design. Included with your kit is a
Linx CW Series connectorized whip antenna 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.
Page 8
www.connectorcity.com
Through its Connector City division, Linx offers a wide
selection of high-quality RF connectors, including FCC-
compliant types such as RP-SMAs that are an ideal
match for our modules and antennas. Connector City
focuses on high-volume OEM requirements, which
allows standard and custom RF connectors to be offered
at a remarkably low cost.
Page 9