PC TO PC WIRELESS COMMUNICATION THROUGH RF LINK-:

shootceaselessUrban and Civil

Nov 16, 2013 (3 years and 9 months ago)

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PC TO PC WIRELESS
COMMUNICATION THROUGH
RF LINK
-
:




INTRODUCTION
-
:

A computing device, such as a laptop personal computer
(PC), a desktop PC, or a personal information device
(PID), includes an antenna embedded therein for wireless
communications. The antenna may be formed on a
printed circuit board installed in the compu
ting device.
The antenna may include multiple radiating and receiving
elements for mitigating multipath effects and/or
responding to steering circuitry
to form a directed
antenna beam through RF link.

We can use wireless RF links to connect two PCs throug
h
serial port to communicate to each other. The coding is
in C to chat between two PCs or send a file through RF
Link at the

distance

of

approx. 10 meters.



Figure
1


Short for
r
adio
f
requency
, any frequency within the
electromag
netic spectrum associated with radio wave
propagation. When an RF current is supplied to an
antenna, an electromagnetic field is created that then is
able to propagate through space. Many wireless
technologiesare based on RF field propagation.

These frequencies make up part of the
electromagnetic
radiation

spectrum:



Ultra
-
low frequency (ULF)
--

0
-
3 Hz



Extremely low frequency (ELF)
--

3 Hz
-

3 kHz



Very low frequency (VLF)

--

3kHz
-

30 kHz



Low frequency (LF)
--

30 kHz
-

300 kHz



Medium frequency (MF)
--

300 kHz
-

3 MHz



High frequency (HF)
--

3MHz
-

30 MHz



Very high frequency (VHF)
--

30 MHz
-

300 MHz



Ultra
-
high frequency (UHF)
--

300MHz
-

3 GHz



Super high frequency (SHF)
--

3GHz
-

30 GHz



Extremely high frequency (EHF)
--

30GHz
-

300
GHz





Here is a pin description of
CC2500 RF module
-
:



RF moduels are availbale in 2 pin connection format

1 with staright 3 pin connector for power and UART
data
and 2nd where both the connectors mounted vertically the
pin position may change but sequence is as it is.


You can see in the image above left 1 module is having
straight connectors where right one is with vertical
connectors

Now to connect the RF m
odule to PC you will need 3 pin
and 2 pin connector each.Which will be connected to your
RF module.At PC side you have to use 9 pin female
connector.


Lets see how to build that 9 pin connector

first you have to take 3 pin connector with long
wires.Strip
the other end of wire with cutter and then
tream it. As you can see wire i m using is 3 color wire
which is generally used for servo connection.terminolgy
for this wire here is

1 >> BLACK = Ground

2 >> RED = TX of module

3 >> YELLOW = RX of module

so now f
irst make a cable for UART.


you will need one 9 pin female connector , plastic casing
of same ,3 pin connector with cable ,soldering iron and
some soldering metal

First solder the 3 ends of wire to 9 pin connector as shown
in figure


as you can see

pin

number 2,3 and 5 are connected to 3 pin connector

pin number 2 is connected to Yellow wire that is RX of
module

pin number 3 is connected to Red wire tha is TX of
module

and pin number 5 is connected to black wire that is
Ground

solder all three wires wit
h soldering iron as shown in
figure and then mount plastic casing on it so your serial
connector will be ready to use



THEORY
-
:

With the technology of the early 20th century, radio
communication systems required:

1.

The production of radio frequency alternat
ing
electrical energy at a transmitting station
.
Alternating currents are set up in the transmitting
circuit, of suitable frequency and of great intensity
(or high voltage). This insures a high rate of variation
of the interlinked electrostatic and electro
magnetic
fields and a great magnitude of these variations.


2.

The

radiation of this energy into space
. The
transmitting circuit is given a shape suitable for
producing fields extending to great distances and
generally in the direction of the receiving
circuits more
than in other directions.

2.

The absorption of a portion of this electromagnetic
energy at the receiving stations and its
transformation into some form of energy capable of
affecting some one of the human senses
. The
receiving circuit is given s
uch a shape and position as
to link it with as large a proportion of the field of the
transmitting circuit as possible.

In modern systems, systems transmission intensity is
sometimes

very small. The power consumed in a
transmitting station varies depending

on the distance of
communication and the transmission conditions. The
power received at the receiving station is usually only a
tiny fraction of the transmitter's output, since
communication depends on receiving the
information
,

not
the
energy

that

was tr
ansmitted.


BLOCKDIAGRAM
-
:



CONCLUSION
-
:

It
allows

communicating

with the pc.


The thought would
be to have the trans
mitter connected to the transmitter
and
the receiver connected
to the PC.

In that way
it
detects

something and notifies the PC.


The PC would monitor
the serial port and then do an action based on the v
alues
passed
.




Reference
-
:

1.

Keil Software, dScope Debugger,
http://www.keil.com/


2.

National Instruments Multisim

10.0
www.ni.com/
multisim