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Electronics => Electronics => Topic started by: aruna1 on September 09, 2009, 05:42:04 AM

Title: need help to send data through air using RF
Post by: aruna1 on September 09, 2009, 05:42:04 AM
hello guys, can you help me to build a transmitter receiver pair to send and receive data sequence? like "1011001" ? i heard RC toys use 27 MHz to do this.but in my country RC toys are not allowed. i want make transmitter receiver pair that will work on about 10meters.
thanks.
 :)
P.S. I was wondering can we use AM to send 1010 signal? ???
Title: Re: need help to send data through air using RF
Post by: Half Shell on September 09, 2009, 06:41:00 AM
A very, very simple and cheap set of solutions are available on Sparkfun.

http://www.sparkfun.com/commerce/categories.php?c=16 (http://www.sparkfun.com/commerce/categories.php?c=16)

Look at the various RF breakout boards they have. It is even cheaper if you're willing to do the breakout yourself and just buy the components individually. These are slow, but go far beyond your requirement range. And being cheap to implement is important, at least to me.

Things to worry about:
Noise. These can suffer from it severely depending on where you are using them and what's in the area. Furthermore, there's no protection against that - you have to use your own methods for detecting a disconnect in communication.

Hope this helps.
Title: Re: need help to send data through air using RF
Post by: aruna1 on September 09, 2009, 06:48:33 AM
well,i was considering about buying stuff locally (i don't have a credit card).anyway in considering your suggestion do this item need http://www.sparkfun.com/commerce/product_info.php?products_id=8950  (http://www.sparkfun.com/commerce/product_info.php?products_id=8950)
external antenna. and are they plug and play type? (i mean in transmitter all i have to do is input data sequence?. but in receiver i see nearly 8 pins  ???)

and can you comment about using AM to send data i mentiond in my firs post.

thank you for replying.
Title: Re: need help to send data through air using RF
Post by: Half Shell on September 09, 2009, 07:21:10 AM
They should work to their adveritisied distance, but you can extend the range with an antenna.

And if you buy a receiver/transmitter of the same frequency then yes, you can just plug and play.
Title: Re: need help to send data through air using RF
Post by: aruna1 on September 09, 2009, 07:22:23 AM
thank you very much
Title: Re: need help to send data through air using RF
Post by: Half Shell on September 09, 2009, 07:30:43 AM
thank you very much

Here is a quick project I found using these modules:
http://www.glacialwanderer.com/hobbyrobotics/?p=291 (http://www.glacialwanderer.com/hobbyrobotics/?p=291)

A nice little, super simple walk through for you  ;D
Title: Re: need help to send data through air using RF
Post by: aruna1 on September 09, 2009, 08:01:33 AM
man shipping is expensive than the product
Title: Re: need help to send data through air using RF
Post by: Half Shell on September 09, 2009, 08:47:00 AM
man shipping is expensive than the product

This, unfortunately, is often the case when doing electronics in hobby quantities.
Title: Re: need help to send data through air using RF
Post by: aruna1 on September 09, 2009, 09:58:06 AM
can noise removed by using a schemit trigger at receiver?
Title: Re: need help to send data through air using RF
Post by: pomprocker on September 09, 2009, 10:06:23 AM
maybe you can hack some toy walkie talkies?
Title: Re: need help to send data through air using RF
Post by: aruna1 on September 09, 2009, 11:06:20 AM
man shipping is expensive than the product

This, unfortunately, is often the case when doing electronics in hobby quantities.
you guys must be realy rich.at sparkfun one 22pf ceramic cap is $0.25. we can buy 25 pieces of 22pf for that price in sri lanka
Title: Re: need help to send data through air using RF
Post by: Half Shell on September 09, 2009, 12:59:12 PM
man shipping is expensive than the product

This, unfortunately, is often the case when doing electronics in hobby quantities.
you guys must be realy rich.at sparkfun one 22pf ceramic cap is $0.25. we can buy 25 pieces of 22pf for that price in sri lanka

I buy my stuff from digikey usually, sometimes mouser. Even still sometimes shipping costs more than the parts I need. That's the point I'm making.
Title: Re: need help to send data through air using RF
Post by: Joker94 on September 09, 2009, 08:13:52 PM
shipping is always a problem.

Remember to always spend as much time as you can afford to search for products, always compare the unit cost and don't forget to compare shipping.

what i am saying is if you want to save money always spend time shopping around as some places have sales and low shipping and another place may have a deal with the supplier, prices change and new shops come on the market.