I would like to connect a XBee module (Zigbee) and also a GSM modem for voice and SMS. From what I have seen, mostly both uses the Rx, Tx pins of Pi for serial communication. Other option would be to connect it over USB. So, if I connect Zigbee through Rx, Tx pins and use a RS-232 to USB cable to connect the GSM modem, will that be fine...?
The GSM Modem will look like this