Mapping a sensor interface and a reconfigurable communication system to an FPGA core

In this paper, we present a novel approach for integrating a standard sensor interface and a reconfigurable wireless data communication channel on a single Field Programmable Gate Array (FPGA) chip. In a traditional wireless sensor device, sensor and communication electronics are built as separate components and their integration consists of designing a board to accommodate multiple integrated circuits (ICs). In contrast, the FPGA core allows us to put a standard I₂C sensor interface, embedded Digital Signal Processing (DSP) algorithms for Software-Defined Radio (SDR), and a microprocessor control system on a single-chip reconfigurable device. In our experimental FPGA-based sensor platform, the I₂C interface is used both to receive data from the temperature sensor and to control the analog Radio Frequency (RF) transceiver board. Amplitude Shift Keying (ASK) modulation and demodulation are implemented using DSP techniques within an SDR framework, and the microprocessor system is used to read sensor data and control various components. The prototype design was deployed on a Nallatech development board containing a Xilinx Virtex 2V3000 FPGA chip and was successfully tested with Dallas Semiconductor DS1721 digital temperature sensor. One instance of the prototype transmitted the temperature red by the sensor while second instance acted upon the received over the air temperature readings by turning LED on or off.