[SOLVED] Rf module not working

[burrow]

Hai, i have a simple communication circuit using 315MHZ RF Module and ht12d and ht12e Ic's

The circuit works fine when i connect ht12d and ht12e directly using wire.

But it doesn't work with RF module. Iam using 5v supply.

Is their anything else i should try out before concluding the module is dead

 

[Ogu Reginald]

Yes, remove all your connections and do the connections again. Check the datasheet very well to check if you are making the right connections. There are RF modules that have variable frequency of operation, if it is this type that you are using, make sure that the transmitter and the receiver are working on the same frequency.
Good luck.

 

[jiripolivka]

Yes, remove all your connections and do the connections again. Check the datasheet very well to check if you are making the right connections. There are RF modules that have variable frequency of operation, if it is this type that you are using, make sure that the transmitter and the receiver are working on the same frequency.
Good luck.

Many users of RF modules have similar problems.
To test the RF transmitter module, one would need a spectrum analyzer to make sure it meets the specifications. To test the receiver module, one needs a calibrated signal generator. Plus antennas, etc.

I would suggest you to get one new transmitter-receiver pair (modules), and test it for data transmission. Then you have a tested transmitter suitable to test one or more receivers, and a receiver suitable to test one or more transmitter modules.
Use the new good pair only for testing, and if the units are tunable (coils, etc.) try to adjust them for the best response. Never touch the new pair and use it only as a standard to test the other modules.

This way you need no expensive test equipment and you have a reference against which you can test other modules.

 

[burrow]

May be i can get my hands on CRO in my college, If i get a chance to use CRO , how can i test the transmitter ?

What wave i should get ?. I haven't used CRO yet. so to be frank i have no idea how to use it

 

[jiripolivka]

First of all, you should learn how to use a CRO to observe digital signals.
Then you can follow your signals in your modules.

How do you know now that your modules are working when directly connected (what points?) by a wire? Using an oscilloscope is a must when working in digital circuits.

 

[burrow]

First of all, you should learn how to use a CRO to observe digital signals.
Then you can follow your signals in your modules.

How do you know now that your modules are working when directly connected (what points?) by a wire? Using an oscilloscope is a must when working in digital circuits.

I was testing rest of the circuit by connecting output of HT12E to input of HT12D.
I was getting "valid transmission" signal.

 

[jiripolivka]

I was testing rest of the circuit by connecting output of HT12E to input of HT12D.
I was getting "valid transmission" signal.

If you rely only on that signal, you cannot see what can happen when "no valid transmission" is indicated. You can (and should) use an oscilloscope to find how the correct signal is transmitted an what distortion makes "no transmission" indication.

My recommendation to use a "healthy" pair still holds, plus use the scope to find the problem.

 

[burrow]

Also another simple question. it may sound stupid but please reply.
In all my previous project i was using Rf transmitter that has 8 pins.

Yesterday in one of the website i saw one with just 4 pins. Is it almost same ( of course except the pinout ), Can they be used to same purpose as those 8 pin ones ?

another question is say i use a 433mhz Rf module with ht12e ic with some address set in it.
can i use another such set (433 mhz ) in the same environment by setting a different address in HT12E.

will their be clash of signals ?