Parallax 27986, 27987, 27988 User Manual

599 Menlo Drive • # 100 • Rocklin, CA 95765

Sales / Technical Support - Tel: [phone] Fax: [phone]

RF MODULES

433.92 MHz

433.92 MHz

433.92 MHz

Part # 27988

Part # 27986

Part # 27987

Compatible with:

Receiver

Part # 27987

Compatible with:

Transmitter
Transceiver

Part # 27986

Compatible with:

Transmitter

Part # 27986

Single Direction

Bi-Directional

Single Direction

TRANSMITTER

Send Only

Transceiver

Part # 27988

TRANSCEIVER

Send and Receive

Receiver

Part # 27987

RECEIVER

Receive Only

Transceiver

Part # 27988

GENERAL DESCRIPTION

There are three Wireless RF Modules, Transmitter, Receiver and a Transceiver. These RF Modules are
designed to serve as a tool for electronic design engineers, developers, hobbyists and students to perform
wireless experiments. These modules make it easy for any NON RF Experienced developer to add Wireless
RF Remote Control to their project. NO RF Knowledge required. The RF Modules are in a PCB (Printed Circuit
Board) form with a 17 Pin 0.1 Inch spacing header that fits directly into most all prototyping boards. They are
easy to use boards that include encoders, decoders, addressing, RF data processing and even the antenna, in
a simple fully range tested board, that is ready to plug right into your project. Just apply +5VDC, ground, and
the communication pins you require and enjoy hassle free wireless communications.

The Transmitter, Receiver and Transceiver all have 9600 baud serial interfaces and stand-alone, 3 function
switch inputs and outputs. The modules can communicate over distances up to 250 feet. The boards operate
on +5V and easily interface to your Basic Stamp 2 or Basic Stamp 2sx.

Web: http://www.parallaxinc.com or http://www.stampsinclass.com • Email: [e-mail]

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599 Menlo Drive • # 100 • Rocklin, CA 95765

Sales / Technical Support - Tel: [phone] Fax: [phone]

RF MODULES

MINIMAL REQUIREMENTS

Two Modes of Operation:

Connecting GND to the Mode pin places the module in Switch Mode.
Connecting +5V to the Mode pin places the module in Serial Mode.

Switch Mode:

The transmitter, receiver and transceiver have 4 address pins (labeled ADDR1 – ADDR4), providing 16 address
combinations. Placing 0V or 5V on the 4 address pins sets the unit’s address (in a binary fashion). For
example, placing 0V on all pins sets the address to zero. Placing 5V on all pins sets the address to 15.

The transmitter, receiver and transceiver also have 3 switch data pins (labeled IN1 – IN3). 0V or 5V logic levels
placed on the input pins of the transmitting module are automatically sent to the output pins (labeled OUT1 –
OUT3) on the receive module. In addition, 16 different modules can be addressed with the built-in 4-bit address
pins. The receiver will receive the switch data on its 3 switch output pins only when its 4-bit address matches
the transmitter’s 4-bit address. The 4-bit address does not apply to serial mode.

Serial Mode

In serial mode (with +5V applied to the Mode pin) the modules can send and receive serial data at 9600, N, 8, 1
with +5V and 0V logic levels. Simply connect a single wire to the Transmit Data pin (labeled TXD) and send
9600 baud data into the module. The receive module outputs the same data at 9600 baud. All RF data
processing is done automatically by the modules. You cannot send a continuous 9600 baud stream; spacing
between 9600 baud bytes has to be at least 15 milliseconds. A flow control pin is provided for the transmitting
side to assist with achieving maximum efficient throughput. The Parallax Basic Stamp 2 and BASIC Stamp 2sx
have built-in commands to do serial byte pacing and flow-control handshaking in one single instruction (see
source code examples).

Single direction communication requires at least:

Option a: 1 Transmitter and 1 Receiver.
Option b: 1 Transmitter and 1 Transceiver.
Option c: 1 Transceiver and 1 Receiver.

Bi-directional communication requires at least: 2 Transceivers.

Multi Point Communications can be achieved by:

Placing one transmitter at each node that needs to send information.
Placing one receiver at each node that needs to receive information.
Placing one transceiver at each node that needs to send and receive information.

REGULATORY WARNINGS

These modules (boards) are not FCC approved. They are designed to comply with the FCC Part 15 Rules
and Regulations. They are not in a finished product form. They are strictly intended for experimental
purposes only. If you wish to use these modules in an actual product (a non-experimental capacity), the
module must first be designed into the product, then the whole product must be approved by the FCC. For a
list of FCC approved Labs that can test your final product for compliance contact RF Digital Corporation at
[phone] or visit their web site at http://www.rfdigital.com.

Web: http://www.parallaxinc.com or http://www.stampsinclass.com • Email: [e-mail]

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599 Menlo Drive • # 100 • Rocklin, CA 95765

Sales / Technical Support - Tel: [phone] Fax: [phone]

RF MODULES

It is the responsibility of the user to be aware of the regulatory requirements in their area of operation and
application. For exact information contact the FCC Office at:

Federal Communications Commission
445 12th St. SW
Washington DC 20554
[phone]
http://www.fcc.gov

USE OUTSIDE OF THE U.S.A. It is the responsibility of the user to be aware of the regulatory requirements
in their area of operation and application. Contact your local regulatory agency and obtain compliance
information.

For O.E.M. Design-In Guidance for the modules please contact:
RF Digital Corporation
1160 North Central Ave. Suite 201
Glendale, CA 91202
Tel: [phone]
Fax: [phone]
Web: www.rfdigital.com
Email: [e-mail] or [e-mail] or [e-mail]

OPERATION WARNINGS

Do not expose the boards to direct outdoor environment. If they will be used outdoors, keep them away from
water, moisture and direct sunlight.

The serial input and output pins operate at +5V and 0V logic levels. Do not attempt to connect directly to a
computer RS232 port as this will damage the module. Typical levels at a computer RS232 port are +10V
and -10V; these voltages would immediately damage the module. The module is intended to interface
directly with the Basic Stamp 2, the BASIC Stamp 2sx and other +5V logic devices.

Keep the top part of the board (PCB Trace Antenna, opposite end of the 17 pin header) at least 4 inches
away from any object, especially metal, wires and batteries as this will de-tune the antenna, drastically
reducing performance. Laying the module flat on a work desk made of wood, plastic or glass can sometimes
cause problems as well, since some paints contain conductive materials.

Do not touch the adjustable capacitor located at the top of the board. This part is factory tuned and must not
be adjusted. It is set at an optimal operating position and if moved will drastically reduce performance.

If mounting the board, use the mounting holes located in the center and corner of the boards. Only use
plastic stand-offs and plastic screws. Using any electrically conductive materials near the board will reduce
performance of the board.

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599 Menlo Drive • # 100 • Rocklin, CA 95765

Sales / Technical Support - Tel: [phone] Fax: [phone]

RF MODULES

SPECIFICATIONS

For best performance position the module boards as high off the ground as possible, in a horizontal position
and keep as far away from microprocessors (or wires connected to microprocessors) as possible. High
speed switching noise can interfere with reception.

In classroom environments, many transmitters and receivers may be within communication range. When not
in use, disconnect power from your project, including the module, to assure there is no chance for
unintentional transmission. Transmissions from other devices can disallow other students to perform their
wireless experiments.

Mechanical:

Size: 1.75 Inch x 3.25 Inch x 0.4 Inch

Environmental:

Temperature: +10c to +60c

Electrical:

Power: +5 VDC +/- 0.250 VDC

Logic Levels:

Cmos: 0V = Ground = Logic 0 = Logic Low
Cmos: +5V = VDD = Logic 1 = Logic High

Current Consumption:

Transmitter: 10 Milliamp (Condition: Transmitting in switched mode)
Receiver: 15 Milliamp (Condition: Receiving in switched mode, with no output load)
Transceiver: 20 Milliamp (Condition: Transmitting in switched mode)

Note: Loading output pins will add to current consumption.

Maximum Output Loading:

Maximum load per pin is 5 milliamps.
Maximum pin loading total: 15 milliamps.

RF:

Frequency: 433.92 MHz +/- 200 KHz Typical
Transmit: Typical 1 Milliwatt
Receive: Typical -104 dbm

Can drive a single led per output pin, in switched mode with a 470 ohm resistor in series. If it is needed to drive
larger loads, use NPN switching transistors.

Absolute Maximum Voltage On Any Pin: +5.25 VDC, -0.250 VDC

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