Why don't you build up your system.

Build parts and test parts.... in building blocks.... if you build it complete and it fails... where do you start to diagnose the problem(s).... is the problem transmit, or receive, or bad radio's or RF noise, or incorrect protocol, or something else or something else, or something else or something else or something else or something else..... you get the idea.

Test the system in bits (modules)...., then once you know a module works move on to the next. Then connect the modules together,

Eg if you are using the UARTS get one node (micro controller) physically connected to the other node.... an "bullet" proof your protocol..... or better still adopt a known protocol, may be MODBUS, may be S.N.A.P maybe your own.

Build the FSK audio link... (UART NRZ data is not recommended over asynchronous 2 level FSK wireless links...)

The point is - to break the challenge down in to meaty size bits .... work on them "until you own them" (you know them in side out). Test them throughly.

Then bring all the modules together....

If it doesn't work.... you can test each module individually ... since you know them inside out.

You project challenge is very common - and a systematic approach will help you complete it.


Joe