TWS and RWS RF modules

Archiver

Dear Fellow stampers

I wonder if someone out there could possibly point me in the right direction. I'm having a few problems with the··RWS and TWS RF modules. I'm trying to communicate between BS2e stamps and am using the code shown below similar to that available from http://www.rentron.com/rf_remote_control.htm and with the wiring as shown on this page. My first problem is that I can only communicate between the 2 BS2e's using the digital input on the reciever, when I try it on the linear input pin as suggested I get no·communication what so ever? Can anyone possibly tell me why this is? I was led to believe that the linear input was superiour to the digital input. I can get around a range of 150m with the digital input on the reciever and zero at the moment with the linear input? Have I possibly damaged the linear input in some way?
I was also wondering if there's anyway possible to get more range out of these RF modules by adding some kind of amplifier. I was led to believe these were available as an IC and could be wired to the TWS and RWS RF modules to give greater range. Is this true?
Anyway your help, suggestions, directions and general comments would be greatly appreciated as I'm·by no means an·RF expert as you can tell.

Best regards John


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Archiver

Dear Fellow stampers

I wonder if someone out there could possibly point me in the right direction. I'm having a few problems with the··RWS and TWS RF modules. I'm trying to communicate between BS2e stamps and am using the code shown below similar to that available from http://www.rentron.com/rf_remote_control.htm and with the wiring as shown on this page. My first problem is that I can only communicate between the 2 BS2e's using the digital input on the reciever, when I try it on the linear input pin as suggested I get no·communication what so ever? Can anyone possibly tell me why this is? I was led to believe that the linear input was superiour to the digital input. I can get around a range of 150m with the digital input on the reciever and zero at the moment with the linear input? Have I possibly damaged the linear input in some way?
I was also wondering if there's anyway possible to get more range out of these RF modules by adding some kind of amplifier. I was led to believe these were available as an IC and could be wired to the TWS and RWS RF modules to give greater range. Is this true?
Anyway your help, suggestions, directions and general comments would be greatly appreciated as I'm·by no means an·RF expert as you can tell.

Best regards John

'**********************************************************
'Transmitter Code
'***********************************************************
x var word
N2400 con 17197
RFdata var byte
sync con "A"
junk con 126
DIRS =· %0110111111100000
OUTS = %0000000000000000

Main:
for x = 0 to 10
RFdata· =· x
serout 7,N2400,[noparse][[/noparse]junk,sync,RFdata]
pause 100
next
goto main

'*****************************************************************
'Reciever code
'*****************************************************************
sync con "A"
RFdata var byte
N2400 con 17197

DIRS = %1000000000000001

Main:
serin 0,N2400,[noparse][[/noparse]Wait(sync),RFdata]
pause 1
Debug Dec RFdata,cr

goto main

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Archiver

John,

>My first problem is that I can only communicate between the 2 BS2e's using the
digital input on the reciever, when I try it on the
linear input pin as suggested I >get no communication what so ever? Can anyone
possibly tell me why this is? I was led to believe
that the linear input was superiour to the digital input. I can >get around a
range of 150m with the digital input on the reciever
and zero at the moment with the linear input? Have I possibly damaged the linear
input in >some way?

You can use either output on the receiver, but most people get better results
using the linear output of the RWS-434 for serial
communications.
The linear output is primarily designed for audio, but (in most) applications,
people get the best results using the linear output.

We have another project using the BASIC Stamp with the TWS/RWS at:
http://www.rentron.com/Stamp_RF.htm

> I was also wondering if there's anyway possible to get more range out of these
RF modules by adding some kind of amplifier. I was
led to believe these were >available as an IC and could be wired to the TWS and
RWS RF modules to give greater range. Is this true?
> Anyway your help, suggestions, directions and general comments would be
greatly appreciated as I'm by no means an RF expert as you
can tell.

I don't recommend using an amplifier to increase the output of these modules
primarily because you are then violating FCC
regulations. The recommended antenna length (as shown in the schematics you
should have received), can be increased from 1/4 wave to
half-wave or full-wave. This will help increase operating distance under most
circumstances.

Linx Technologies has amplifiers for these at: http://www.linxtechnologies.com
They also have some excellent RF equipment with
considerably better range than the TWS/RWS modules. I highly recommend
downloading the free application notes from the linx site.
These will give you some insight into what's necessary to achieve better range,
some rules of the road, antenna design, and many
other useful details for implementing RF.

The following application notes from Linx are a good place to start:

RF 101: Information for the RF Challenged
http://www.linxtechnologies.com/pdfs/AN00100.pdf
Considerations for operation within 260-470MHz band
http://www.linxtechnologies.com/pdfs/AN00125.pdf
Modulation Techniques for low-cost RF Data Links
http://www.linxtechnologies.com/pdfs/AN00130.pdf
Antennas: Design, Application, Performance
http://www.linxtechnologies.com/pdfs/AN00500.pdf


-Bruce
webmaster@r...
http://www.rentron.com