We increasingly encounter radio-frequency identification (RFID) systems in our lives and work. From inventory control to fast checkouts at the supermarket, the technology is transforming many existing applications and enabling new ones. At the front end, the “signal chain” starts with small tags attached to the units of interest; the tags convey information in the form of a bit stream to an RFID reader that detects when tags are present in a specific area, and reads the information they carry. At the back end, a server-based system maintains and updates the tag database, generating alerts or initiating other information-based processes within the enterprise.

Most RFID readers currently employ more than one processor to satisfy application requirements. Typically, a signal processor is interfaced to an analog-to-digital converter (ADC) and a digital-to-analog converter (DAC). Then a network processor communicates with a local or remote server for information storage and retrieval. This article describes how these seemingly disparate functions&#151signal conversion and network connectivity&#151can be managed by a single processor from the Analog Devices Blackfin processor family.

We start with a brief overview of RFID technology, and discuss the present and future applications it enables. Then, focusing on RFID reader functionality, we explore the basic software components that need to run on the RFID reader&#151as well as the server connections. Finally, some block diagrams offer a few suggestions for system configurations.

Reproduced with the permission of Analog Devices, Inc.