It's possible to connect Raspberry Pi UART on 
PCB board pin header directly to the sensor.

This is an enconomical and energi saving way.


You need to connect jumper wires between the 
devices.

http://www.radio-sensors.com/pictures/RPi-UART.jpg

+5V
GND
RX
TX

On the sensor node 

http://www.radio-sensors.com/pictures/RPi-sensor-s6pin-header.jpg


The terminal device to be used in RPi is /dev/ttyAMA0.

Suggest to try out communication first with a terminal program
like minicom. sensd builds on RPi.