digi.com that uses ZigBee protocol. “ZigBee is a specification for a suite of high level communication protocols using small, low-power digital radios based on the IEEE 802.15.4-2003 standard for wireless personal area networks (WPANs), such as wireless headphones connecting with cell phones via short-range radio. The technology defined by the ZigBee specification is intended to be simpler and less expensive than other WPANs, such as Bluetooth. ZigBee is targeted at radio-frequency (RF) applications that require a low data rate, long battery life, and secure networking.” (from wikipedia)
It operates with 3.3V and uses 50mA (series 1). Some Xbee ‘s pins can be set as Analog Input, Digital Input, Digital Output, or Analog Output (PWM). The numbers of pins are up to seven channels of analog input, nine channels of digital I/O and two channels of PWM. This means you do not need microcontroller to send sensor input to your computer. This example need two Xbee Series 1 802.15.4 with firmware version 10A1 or later (I used 10A5), or two Xbee Seriese 2 with ZNET 2.5 CORDINATOR API and ZNET 2.5 ROUTER/END DEVICE API firmware. The following setup is how to do Sensor-Xbee-Comp connection with Xbee Series 1 802.15.4.
Pin configuration of Xbee Series 1 802.15.4 and Xbee pro. The table is taken from Xbee manual