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433.92 MHz
TRANSMITTER
Part # 27986
Single Direction
Send Only
Compatible with:
Receiver
Part # 27987
Transceiver
Part # 27988
GENERAL DESCRIPTION
There are three Wireless RF Modules, Transmitter, Receiver and a Transceiver.
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: stamptech@parallaxinc.com
Sales / Technical Support - Tel: (916) 624-8333 Fax: (916) 624-8003
599 Menlo Drive • # 100 • Rocklin, CA 95765
433.92 MHz
TRANSCEIVER
Part # 27988
Bi-Directional
Send and Receive
Compatible with:
Transmitter
Part # 27986
Receiver
Part # 27987
Transceiver
Part # 27988
© 1-27-2000, V1.0 • Mfg. by www.RFDigital.com
RF MODULES
433.92 MHz
RECEIVER
Part # 27987
Single Direction
Receive Only
Compatible with:
Transmitter
Part # 27986
Transceiver
Part # 27988
These RF Modules are
1
Page
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Table of Contents
Summary of Contents for Parallax 27986
- Page 1 RF MODULES 433.92 MHz 433.92 MHz 433.92 MHz TRANSMITTER TRANSCEIVER RECEIVER Part # 27986 Part # 27988 Part # 27987 Single Direction Bi-Directional Single Direction Send Only Send and Receive Receive Only Compatible with: Compatible with: Compatible with: Receiver Part # 27987...
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Page 2: Minimal Requirements
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). -
Page 3: Operation Warnings
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 (202) 418-0190 http://www.fcc.gov USE OUTSIDE OF THE U.S.A. -
Page 4: Specifications
RF MODULES 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. -
Page 5: Pin Description
RF MODULES PIN DESCRIPTION PIN 1: GND: (Input) Ground pin. Connect to power supply ground. PIN 2: +5VDC: (Input) Power Supply pin. Connect to regulated +5VDC, +/- 0.250 VDC. PIN 3: MODE: (Input) Serial/Switch Mode Pin. The Mode Pin, determines if module will operate in switch mode or in serial mode. - Page 6 RF MODULES PIN 10: IN3: (Input) Switch Input 3. Internally pulled down. When left open this pin is logic low. When connected to +5VDC this pin is logic high. A logic high on this pin will send a "1" to the receive pin OUT3. This pin only functions in Switch Mode.
- Page 7 RF MODULES Transmitter = Switch Mode Receiver = Switch Mode Any logic high +5VDC placed on IN1, IN2 or IN3 of the transmitter will be reflected at the receiver’s OUT1, OUT2 or OUT3, respectively. Logic levels on transmitter and receiver address pins ADDR1 to ADDR4 must match.
- Page 8 RF MODULES Transmitter = Serial Mode Receiver = Switch Mode Serial data is input into the TXD pin of the transmitter at 9600, 8, N. Use the table below for addressing the receiver’s 4 address bits and the 3 OUT bits. When a serial byte is transmitted from the transmitter to the receiver (with addresses), OUT1, OUT2 and OUT3 of the receiver will reflect the state of the bit positions in transmitted byte.
- Page 9 RF MODULES Hook-up Using Switch Mode The following example demonstrates an addressable, three-function pushbutton remote control. All inputs including the mode pin are internally pulled low, so when in switch mode, it is not necessary to connect the mode pin. Connecting the mode pin to ground or leaving it open has the same result. The LEDs on the receiver side can be replaced with NPN transistors to be able to drive relays that can be used to switch high current loads.
- Page 10 RF MODULES Hook-up Using Serial Mode Use the Basic Stamp 2 or BASIC Stamp 2sx’s SERIN and SEROUT commands to send and receive 9600, N, 8, 1 bytes. The modules can not send and receive continuous 9600 baud serial data. If the Flow Control (TXFLO) will not be used for sending serial data (TXD), you must have at least 15 milliseconds spacing between the start of each byte.
- Page 11 RF MODULES BASIC STAMP 2 & BASIC STAMP 2SX - SAMPLE CODE Visit our web site for code and documentation updates. http://www.parallaxinc.com Data can be sent and received with these modules simply by using the BASIC Stamp 2 and 2sx’s SERIN and SEROUT commands (for Serial Mode) or simply by setting pins high and low (for Switch Mode).
- Page 12 RF MODULES n+3 doesn’t exist). The second method is based on a Cyclic-Redundancy-Check algorithm. The CRC16, as it is called, uses a sophisticated equation to calculate a checksum that catches 99% of transmission errors and is unaffected by symmetrical data. (If this method is used, Byte n+3 is the last byte of the packet). The Master and Slave use an acknowledge-based protocol to communicate with each other.