Simple RF Transmit and Receive

[chuck]

Also bread boarding is not very good for RF stuff, You could be getting interferance form the bread baord, the best thing is solder or make a baord.

like Kamikaze47 said send some preamble or search here and you will find all about manchester encoding

[Jerson]

First off, the modules require a long wire antenna. What you have connected is a whip antenna which has a ground terminal too. This is not required.

Second, a good preamble is a must.

Third, make sure your code works when wired between tx and rx. Only then, go to the wireless part.

Fourth, make sure your data rate is acheivable by the modules.

JF

[dhouston]

Those are FM modules so you really don't need to worry about a preamble. Just use the carrier detect pin on the receiver to determine when it's receiving a signal. Radiometrix probably has some detailed instructions for their use.

Also, you can ignore the advice re breadboards. The modules are basically self contained and all you need the breadboard for is the interconnections, power, etc. the breadboards won't affect the RF modules.

And the antennas you're using are fine.

[koossa]

Thank you very much!!!!

Will try out all the suggestions

[dhouston]

The test circuit shown on p6 of http://www.radiometrix.com/pdf/tx2rx2.pdf shows how to use the CD pin. You'll need to modify your receiver schematic to add the transistor, resistor and cap. Then, just monitor the /CD signal to determine when a signal is being received. Depending on the response time, you may need to prepend a non-data byte to all messages. FSK signalling is much more reliable than ASK. If you add manchester encoding to FSK, you get a really robust system.

[koossa]

Thank you very much Dave, I will add the manchester encoding!!

[koossa]

What will hapen when 2 or 3 transmitters, transmit at the same time?