Hi Alameer,
Here are a couple of things to check out:
- Do you use two modules with the same operating frequency (ex. 433MHz)?
- Do you use the same bit rate (9600 bps for the D version of the DPC-64-RS232)?
- Did you connect an antenna of the proper length, very close to the pins 21 and 22, to the DPC-64-CTL module?
- Do you use a switching mode power supply to power one or both of the modules?
- Did you test the RF link with the test mode?
- Do you power the modules properly (correct voltage, enough current available, battery sufficiently charged)?
When you diagnose a problem, you should challenge each and every part of your design in order to see where it could fail. When you're satisfied with the answers, you can begin to debug by doing the most basic operation you can do with the system, then you slowly add complexity until your design is functionnal.
cyberblak