Have a few Xbee PRO 900. What I’m trying to do is connect them directly to the Arduino. What i have tried is connecting the tx and rx to there respective pins and the 3.3 and gnd. I am unable to use the X-CTU software. Is there a trick i need to know? I imagine it would work fine if i had firmware loaded and was just sending messages to another Xbee but i need to program with only an Arduino.