Active electronic tag design strategy based on integrated temperature sensor - News - Global IC Trade Starts Here 工业

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Radio Frequency Identification (RFID) technology is an automatic identification technology that has emerged in recent years and is gradually maturing. The technology has been widely used in non-contact, large storage capacity, fast recognition speed, long distance, and multi-card identification. With the maturity of RFID technology and the decline of the cost of RFID tags, some development trends with practical application value are gradually emerging, one of which is the combination of RFID and temperature sensors. At present, in the mine production safety monitoring and monitoring system, the temperature value collected by the cable is generally transmitted, and the cable wire is easily pulled off, broken, and scratched, thereby causing the spark to trigger the gas and causing mine disaster. Combining the temperature sensor with the RFID technology not only enables automatic identification, but also forms a serial data acquisition wireless transmission method, which makes the entire detection device small in size and saves a lot of wiring work. The device can be installed on the helmet of the miner, which facilitates real-time monitoring, reduces the interference in the actual temperature measurement, and greatly improves the reliability and accuracy [3].
This paper expounds the R&D design of the integrated temperature sensor active electronic tag from two aspects of hardware structure and software structure. The active electronic tag can detect the temperature value stably and reliably and perform wireless communication.
1 The hardware structure and working process of the system In the hardware structure, the active electronic tag integrated with the temperature sensor is mainly composed of a wireless RF module, an antenna, a microcontroller (MCU), a sensor, and a power module. Its hardware structure is shown in Figure 1.

After the electronic tag is powered on, the wireless RF module and the sensor are first initialized, and the transceiver address, the sending and receiving frequency, the transmitting power, the wireless transmission rate, the wireless transceiver mode, and the length and validity of the CRC check of the RF transceiver in the RF chip are completed. The data length and other information are set, and then the microcontroller sends the data collected by the sensor to the radio frequency chip through the communication interface, and the radio frequency chip is sent out through the transmission mode [4].
1.1 chip on chip CC2430
The CC2430 includes a high-performance 2.4 GHz Direct Sequence Spread Spectrum (DSSS) RF transceiver core and an industrial-grade compact and efficient 8051 controller that combines a radio frequency (RF) front end, memory and microcontroller on a single chip . It has the following features: (1) using an 8-bit MCU (8051) with 32/64/128 KB programmable Flash and 8 KB of RAM; (2) extremely high receiving sensitivity and anti-interference performance; (3) Data retention capability in a variety of power modes; (4) requires very few external components; (5) low current consumption (when the microcontroller core is running at 32 MHz, Rx is 27 mA, Tx is 25 mA ), especially suitable for applications requiring very long battery life [5].
1.2 Introduction to Temperature Sensor DS18B20
The DS18B20 is a single-line digital temperature sensor manufactured by DALLAS. It is available in a 3-pin TO-92 package. Its stainless steel housing is water and moisture resistant. It is suitable for harsh field temperature detection. Its temperature measurement range is -55°C~+ 125 ° C, programmable 9- to 12-bit A / D conversion accuracy, temperature resolution up to 0.062 5 ° C [6]. Its internal structure is shown in Figure 2.

1.3 DS18B20 and CC2430 interface design temperature sensor DS18B20 and chip CC2430 hardware connection is very simple, as shown in Figure 3. Since it combines the address line, data line and control line into a bidirectional serial transmission signal line, it can be controlled separately, so only one I/O line of the CC2430 is occupied.