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View Full Version : Can "Parallax 433 MHz RF Transmitter" be used for long range data communication?



Kashif
02-19-2010, 09:49 PM
Hi,

I have checked the specification of "Parallax 433 MHz RF Transmitter" and the site says, it can support the communication range of up to 500 feet.

I am looking for something that could give me an operating range of a few miles ( or at least a mile plus ).

Can anyone advice me where to look for?

Thanx· & Regards.

P.S: - I am using Basic Stamp 2 with BOE

Mike Green
02-20-2010, 12:13 AM
Digi has some long range wireless modems: www.digi.com/products/wireless/long-range-multipoint/ (http://www.digi.com/products/wireless/long-range-multipoint/)

There's no way you'd be able to use Parallax's transmitter for the kind of range you want. The 500 feet mentioned is a maximum range under ideal conditions.

Keep in mind that the antenna you use is important and antenna positioning is also important for good range. Digi quotes an indoor range of maybe 3000 feet. That's not unusual outdoors with minimal antennas and obstacles between transmitter and receiver.

Post Edited (Mike Green) : 2/19/2010 4:20:47 PM GMT

JD
02-20-2010, 02:56 AM
Kashif,

I agree; the XBEE modules that are available are far easier and better than the 433 MHz in almost every regard. The module I would recommend reviewing is the 60mW XBEE module; which are rated up to a mile outside. Here is the link for you to review the module; keep in mind if you get the module you would want to get an adapter board as the pin layout of the XBEE modules are not the friendliest of connections for prototyping in a breadboard. There is also a patch antenna if space is an obstacle.

XBEE Module [ 60mW ]:
http://www.parallax.com/Store/Accessories/CommunicationRF/tabid/161/CategoryID/36/List/0/catpageindex/2/Level/a/ProductID/641/Default.aspx?SortField=ProductName%2cProductName

XBEE Adapter:
http://www.parallax.com/Store/Accessories/CommunicationRF/tabid/161/CategoryID/36/List/0/catpageindex/2/Level/a/ProductID/639/Default.aspx?SortField=ProductName%2cProductName

Feel free to ask more questions as they arise.

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Respectfully,


Joshua Donelson
www.parallax.com (http://www.parallax.com)

Kashif
02-20-2010, 03:54 AM
Joshua Donelson (Parallax) said...

Kashif,

I agree; the XBEE modules that are available are far easier and better than the 433 MHz in almost every regard. The module I would recommend reviewing is the 60mW XBEE module; which are rated up to a mile outside. Here is the link for you to review the module; keep in mind if you get the module you would want to get an adapter board as the pin layout of the XBEE modules are not the friendliest of connections for prototyping in a breadboard. There is also a patch antenna if space is an obstacle.

XBEE Module [ 60mW ]:
http://www.parallax.com/Store/Accessories/CommunicationRF/tabid/161/CategoryID/36/List/0/catpageindex/2/Level/a/ProductID/641/Default.aspx?SortField=ProductName%2cProductName

XBEE Adapter:
http://www.parallax.com/Store/Accessories/CommunicationRF/tabid/161/CategoryID/36/List/0/catpageindex/2/Level/a/ProductID/639/Default.aspx?SortField=ProductName%2cProductName

Feel free to ask more questions as they arise.


Dear Joshua,

Thanx for the info. "60mW XBEE module" which you have recommended will surely solve my problem for now.
Just to confirm, I will need a pair of XBEE Pro modules with a pair of respective adapters to form a transmitter/receiver link, right?

What about the transmission rate? Actually, I want to use the above combination to replicate the behavior of R/C controlled vehicles.
So I need a real time transmission/reception that as I send the commands from my PC, they should be received immediately by the receiving module (connected to Basic Stamp), which would in turn control the motors/servos etc to control the motion.


·

Kashif
02-20-2010, 03:57 AM
Mike Green said...
Digi has some long range wireless modems: www.digi.com/products/wireless/long-range-multipoint/ (http://www.digi.com/products/wireless/long-range-multipoint/)

There's no way you'd be able to use Parallax's transmitter for the kind of range you want. The 500 feet mentioned is a maximum range under ideal conditions.

Keep in mind that the antenna you use is important and antenna positioning is also important for good range. Digi quotes an indoor range of maybe 3000 feet. That's not unusual outdoors with minimal antennas and obstacles between transmitter and receiver.
Dear Mike,

Thanx for your reply. The modules you have recommended are a bit out of my budget as a hobyist ;-)
But I will surely look into them soon after completing my working prototype.

Thanx again for taking time to clear my "fundamentals", much appreciated.

Mike Green
02-20-2010, 04:03 AM
Yes, you would need a pair of modules with adapters.

The data transfer is done in packets. The xBee module buffers the data for a period of time and transmits the data either when a certain amount of data has been collected or when the configurable period of time has expired. The default settings are very reasonable for most replacements of a serial wire connection with a wireless connection. As far as you're concerned, the transmission/reception will feel like real time. You can always adjust the timing parameters.

Transmission errors and retries are handled automatically by the modules and will slow down the apparent transmission speed.

JD
02-20-2010, 07:38 AM
I couldn't have said it better.

There is also an adapter board that you can get if you want to delve into the other features of the XBEE module. The USB version of the adapter board enables you to connect to the PC using the Digi program to configure the XBEE modules to use advanced techniques and command set; however, for the most part the default settings are enough unless you need something specific for your applications such as mesh networking.

XBEE USB Adapter Board:
http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/XBEE/List/0/SortField/4/ProductID/643/Default.aspx

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Respectfully,


Joshua Donelson
www.parallax.com (http://www.parallax.com)

electrosys
02-20-2010, 07:40 AM
Hello Kashif,
Here·are some quite·inexpensive RF transmitter at operating frequency: 315 MHz, 433 MHz and selectable,
as you can see it's TXD-RXD and type of output is·TTL,

TM4000-1 (http://cgi.ebay.com/4000m-RF-Wireless-Radio-Transmitting-Module-TM4000-1_W0QQitemZ300365598507QQcmdZViewItemQQptZRadio_Co ntrol_Vehicles?hash=item45ef2f4f2b)·has a distance: 4000m·and·TM1000-1 (http://cgi.ebay.com/1000m-RF-Wireless-Radio-Transmitting-Module-TM1000-1_W0QQitemZ290368703543QQcmdZViewItemQQptZRadio_Co ntrol_Vehicles?hash=item439b52cc37)·has a distance: 1000m, and also a receiver RM1SH (http://cgi.ebay.com/Wireless-Radio-Superheterodyne-Receiver-Module-RM1SH_W0QQitemZ300365598720QQcmdZViewItemQQptZGara ge_Doors_Openers?hash=item45ef2f5000)·,
Take a look, there are much more, you maybe find·some that better is suitable to your project.



· http://www.e-madeincn.com/eBayImages/TM4000-1b.gif······· http://www.e-madeincn.com/eBayImages/TM1000-1A.gif············· http://www.e-madeincn.com/eBayImages/RM1SH-1.jpg

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At the end, everything will became Electron...!

$WMc%
02-20-2010, 10:43 AM
Kashif

Have You tried reducing R5 on Your RF-TXer?

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The Truth is out there············___$WMc%___······················ ······ BoogerWoods, FL. USA