MDEV-900HP3SPS-RS232 Linx Technologies Inc, MDEV-900HP3SPS-RS232 Datasheet - Page 3

• Manufacturer Part Number: MDEV-900HP3SPS-RS232
• Description: RF Modules & Development Tools HP-3 Master Dev Sys SMD, RS232 Module
• Manufacturer: Linx Technologies Inc

Specifications of MDEV-900HP3SPS-RS232

• Supply Voltage (min): 7 V
• Product: RF Development Tools
• Supply Voltage (max): 16 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

GETTING STARTED
CHANNEL SELECTION
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Parallel Selection
Serial Selection
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.
All HP3 models feature eight parallel
selectable channels. Parallel mode is
selected by grounding the module's MODE
line (default setting). Mode Switches SW2
(TX) and SW3 (RX) have been provided to
allow the developer to easily switch between
parallel and serial modes. In parallel mode,
channel selection is determined by the logic
states of lines CS0, CS1, and CS2, as shown
in the adjacent table. DIP switches are used
on the development boards to set the
channels. If the switch is set to ON, then the
pin is connected to ground, otherwise it is
pulled up inside the module. The DIP switch
positions on both boards must match in order for the modules to communicate.
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.
Table 1: Channel Selection Table
CS2
0 = On/Low
0
0
0
0
1
1
1
1
CS1
0
0
1
1
0
0
1
1
CS0
1 = Off/High
1
0
1
0
1
0
1
0
Channel
0
1
2
3
4
5
6
7
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.
Once
configured, place the receiver board on
a flat surface and turn it on. Turn on the
transmitter board and press button S3.
You should hear the buzzer on the
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.
the
boards
have
been
Figure 3: Jumper Configuration
JUMPER CONFIGURATION
TX
J1
HOST TX
TX DATA
ENCODER
TX MODE
TX PDN
TX CTS
TX CS2/DATA
TX CS1/CLK
TX CS0
GND
SIMPLEX RANGE TEST
(Factory Default)
HOST RX
RX DATA
DECODER
RX AUDIO
RX MODE
RX RSSI
RX PDN
RX CS2/DATA
RX CS1/CLK
RX CS0
RX
J1
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