Wireless sensor implemented by using radio frequency identification (RFID) tag

Abstract

The invention discloses a wireless sensor implemented by using a radio frequency identification (RFID) tag. The wireless sensor comprises the RFID tag and a 1-wire state machine, wherein the RFID tag comprises an antenna, a radio frequency front-end circuit, a signal processing circuit, a collision detection logic circuit and an electrically erasable programmable read-only memory (EEPROM); an input end of the 1-wire state machine is connected with the EEPROM, and an output end of the 1-wire state machine is connected with a register and connected with the antenna through the signal processing circuit; the register is connected with a 1-wire sensor; a 1-wire command query table is stored in the EEPROM; the state machine sequentially reads commands from the EEPROM, drives a 1-wire bus and executes a sensor data reading function, and data which are read are stored in the register; and after a collision detection unit detects that collision does not exist, the RFID tag sends identifiers (ID) which are stored in the EEPROM and sensor data which are read to a reader-writer. The wireless sensor has the advantages that functions of a wireless sensor network are realized by using the conventional low-cost RFID tag circuit, the sensor data are read by using the conventional RFID reader-writer instead of special sensor reading equipment, and various 1-wire sensor types and topological structures are supported.

Description

technical field [0001] The invention relates to a wireless sensor, in particular to a wireless sensor realized by using an RFID tag. Background technique [0002] A wireless sensor network consists of dozens, hundreds, or even thousands of scattered sensors to monitor physical or environmental variables. Each sensor is a node, and multiple sensors are connected through different topological structures to form a network. There are many topological structures, such as star type, grid type, and so on. Its upper layer protocol also has functions such as routing, relay and data overflow prevention. The basic structure of a wireless sensor includes: RF transceiver, antenna, microprocessor, sensor interface, power supply (battery or power harvesting device). [0003] Wireless sensor network technology has been developed along with the development and application of wireless technology in the last 10 years. At present, IEEE802.15.4 is the main technical standard, which defines th...

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Problems solved by technology

[0010] The main problem of various current solutions is cost. Sensor networks based on 802.15.4 are all active sensors. Their reliability, maintenance requirements, and complexity all lead to high cost, which is the biggest problem restricting their wide application.

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