Data acquisition system based on NFC electronic tag

Abstract

The utility model provides a data acquisition system based on an NFC electronic tag. The data acquisition system comprises an NFC induction module, a microcontroller, a data transmission module, a sensor signal amplification circuit, a multi-signal conditioning circuit, an analog-to-digital converter and a communication module which are electrically connected. The NFC induction module is used for receiving an induction signal sent by the mobile terminal; the microcontroller is used for sending a control signal to each module; the data transmission module is used for establishing communication with a mobile terminal to realize data transmission; the sensor signal amplification circuit is used for amplifying the collected sensor signal; the multi-signal conditioning circuit is used for performing analog switching on the amplified sensor signal; the analog-to-digital converter is used for carrying out rotation type measurement on the analog signal to enable the analog signal to meet the sampling requirement; and the communication module is used for sending the processed sensor signal and the configuration information of the mobile terminal to a remote cloud platform. The data acquisition system based on the NFC electronic tag is simple in pairing and low in error rate.

Description

Technical Field

[0001] This utility model relates to the field of structural safety monitoring technology, specifically to a data acquisition system based on NFC electronic tags. Background Technology

[0002] Data acquisition equipment used in structural safety monitoring typically requires initial configuration after on-site deployment, including setting operating modes, equipment parameters, channel functions, and sensor parameters. Furthermore, during system operation, modifications to these settings may be necessary due to changes in monitoring factors or sensor replacements.

[0003] Currently, the methods for configuring parameters of data acquisition devices are divided into two types based on the physical medium on which communication depends: wired and wireless. (1) Wired communication: The device is connected via wired methods such as RS232 / RS485, USB, and Ethernet. A computer and an APP on the computer are required. The device is connected by configuring the APP. After successful connection, the configuration information is written to the device. (2) Wireless communication: The device is connected via Bluetooth / WIFI of a mobile phone. Bluetooth pairing is required first (WIFI requires network information configuration). After successful pairing (configuration), the configuration information is written to the device via the APP. However, when configuring the device via wired methods, data transmission cables, computers, and other equipment are required. The size and weight of these equipment will affect the efficiency of on-site work. Although wireless methods do not require data transmission cables, computers, and other equipment, the addition of Bluetooth / WIFI configuration will also affect the efficiency of on-site device configuration. Utility Model Content

[0004] Therefore, the purpose of this utility model is to provide a data acquisition system based on NFC electronic tags to solve the problems existing in the prior art.

[0005] This utility model provides a data acquisition system based on NFC electronic tags, including an NFC sensing module, a microcontroller, a data transmission module, a sensor signal amplification circuit, a multi-signal conditioning circuit, an analog-to-digital converter, and a communication module connected in sequence.

[0006] The NFC sensing module is electrically connected to the mobile terminal and is used to receive sensing signals sent by the mobile terminal to wake up the microcontroller.

[0007] The microcontroller is electrically connected in sequence to the data transmission module, the sensor signal amplification circuit, the multi-signal conditioning circuit, the analog-to-digital converter, and the communication module to send control signals to each module;

[0008] The data transmission module is electrically connected to the mobile terminal and the microcontroller respectively, and is used to establish communication with the mobile terminal to realize data transmission;

[0009] The sensor signal amplification circuit, the multi-signal conditioning circuit, and the analog-to-digital converter are electrically connected in sequence. The sensor signal amplification circuit is used to amplify the acquired sensor signal and improve the signal-to-noise ratio.

[0010] The multi-signal conditioning circuit is electrically connected to the sensor signal amplification circuit and is used to perform analog switching on the amplified sensor signal; the analog-to-digital converter is electrically connected to the multi-signal conditioning circuit and is used to perform polling-style measurement on the analog signal in each sampling channel so that the analog signal meets the sampling requirements.

[0011] The communication module is electrically connected to the microcontroller and the cloud platform, and is used to send the processed sensor signals and the configuration information of the mobile terminal to the remote cloud platform.

[0012] Preferably, the NFC sensing module includes an NFC antenna, an NFC radio frequency conditioning circuit, and an NFC transceiver connected in sequence. The NFC antenna is used to receive NFC radio frequency signals sent by the mobile terminal. The NFC radio frequency conditioning circuit is used to filter and impedance match the NFC radio frequency signals. The NFC transceiver is used to decode the NFC radio frequency signals to wake up the microcontroller.

[0013] Preferably, the NFC antenna includes a first antenna capacitor group and a second antenna capacitor group electrically connected. The first antenna capacitor group includes a plurality of first antenna capacitors connected in parallel and a parallel adjustment resistor. The second antenna capacitor group includes a plurality of second antenna capacitors connected in parallel. The output terminal of the second antenna capacitor group is electrically connected to the input terminal of the NFC radio frequency conditioning circuit.

[0014] Preferably, the input terminal of the NFC radio frequency conditioning circuit is provided with a radio frequency resistor, which is electrically connected to the second antenna capacitor bank. The NFC radio frequency conditioning circuit includes an EMC filter circuit and an impedance matching circuit. The EMC filter circuit is used to filter out the derived high-order harmonics in the antenna signal emitted by the NFC antenna, and the impedance matching circuit is used to adjust the resonant frequency of the antenna transmitting part.

[0015] Preferably, the EMC filter circuit includes an adjusting VSWR capacitor, an adjusting phase capacitor, an adjusting transmit frequency capacitor, and a sampling ASK modulation signal capacitor that are electrically connected, and the impedance matching circuit includes an LC filter composed of a filter capacitor and a filter inductor.

[0016] Preferably, the TX input interface of the NFC transceiver is electrically connected to the frequency adjustment capacitor, and the NFC transceiver includes at least two vertically placed inductors to reduce coupling between the inductors.

[0017] Preferably, the data transmission module is a combined Bluetooth / WIFI module, wherein the Bluetooth module is electrically connected to the WIFI module through RF0 and RF1 interfaces.

[0018] Preferably, the gain coefficient of the sensor signal amplification circuit is controlled by the microcontroller.

[0019] The beneficial effects of this utility model are as follows: The data acquisition system based on NFC electronic tags provided in this application (1) simplifies the pairing process: by combining NFC near-field communication technology with monitoring equipment, users can automatically and quickly pair the device with the mobile APP by simply "touching" the device, which greatly simplifies the traditional wired and wireless configuration process; (2) improves work efficiency: it reduces the time and effort required for on-site personnel to configure the device, thereby improving the work efficiency of on-site device configuration; (3) enhances user experience: the ease of use of the device is significantly improved, and users no longer need to go through complicated steps to connect and configure the device, thereby enhancing user experience and satisfaction; (4) reduces error rate: due to the simplification of the configuration process, the complexity of human operation is reduced, thereby reducing the risk of device failure or communication failure caused by configuration errors; (5) improves security: through the security features of NFC technology, the security of the device pairing process is ensured, unauthorized device access is prevented, and the security of the system is enhanced.

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] Figure 1 A schematic diagram of the data acquisition system based on NFC electronic tags provided by this utility model;

[0022] Figure 2 for Figure 1 Schematic diagram of the NFC sensing module circuit structure;

[0023] Figure 3 for Figure 2 Schematic diagram of the NFC antenna circuit structure;

[0024] Figure 4 for Figure 2 Schematic diagram of the NFC radio frequency conditioning circuit structure;

[0025] Figure 5 for Figure 1 A schematic diagram of the circuit structure of the data transmission module.

[0026] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation

[0027] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0028] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] Specifically, such as Figure 1As shown in the figure, this utility model embodiment discloses a data acquisition system based on NFC electronic tags. The entire system consists of a mobile terminal, an NFC antenna, an NFC radio frequency conditioning circuit, an NFC transceiver, a microcontroller, a data transmission module, a sensor signal amplification circuit, a multi-signal conditioning circuit, an analog-to-digital converter, and a communication module. Optionally, the mobile terminal is a mobile phone. The NFC antenna, NFC radio frequency conditioning circuit, and NFC transceiver together form the NFC sensing module. The NFC sensing module specification is based on the high-frequency RFID ISO and ECMA standards; it is based on 13.56MHz high-frequency passive RFID / contactless card technology, providing a bidirectional link between devices; it supports short-range communication up to 10 cm, depending on the reader, tag antenna geometry, and reader output power; optionally, NFC supports three communication modes: point-to-point mode, reader / writer mode, and card emulation mode. In point-to-point mode, either device can initiate communication, thus facilitating data sharing, such as between two smartphones, or between a mobile phone and a data acquisition device. Two NFC devices can perform bidirectional data transmission. This mode is commonly used for information exchange between devices. The peer-to-peer operating mode requires both NFC devices to generate radio frequency fields, meaning both devices must be self-powered. Each device uses ASK (Amplitude Shift Keying) modulation for data transmission. Therefore, considering the problem this solution aims to address, a peer-to-peer mode is adopted.

[0031] Most smart mobile devices currently support NFC functionality. The main function of the phone is to allow users to "touch" the data collection system. This automatically opens the configuration app on the phone, while the system is activated via the NFC sensing circuit and automatically configures Bluetooth / Wi-Fi information to establish a communication link with the mobile app.

[0032] The NFC antenna is used to receive NFC radio frequency signals sent by the mobile terminal, and to receive and transmit modulated signals. Optional, such as... Figure 2 and Figure 3As shown, the NFC antenna includes C4, C8, R3, C11, and C14 as resonant elements to drive the NFC antenna to achieve parallel resonance of RLC (resistor, inductor, capacitor). R3, C11, and C14 in parallel form the first antenna capacitor group, and C4 and C8 in parallel form the second antenna capacitor group. Adjusting the value of R3 can adjust the Q value of the resonant circuit. Meanwhile, the values ​​of C4, C8, R3, C11, and C14 will vary depending on the antenna's inductance value L, ensuring that the parallel RLC resonant frequency is 13.56MHz. The larger the antenna area, the longer the NFC communication distance. The NFC antenna can use a PCB antenna design or a separate NFC antenna design, depending on the NFC antenna's position on the data acquisition device and ease of contact with the mobile phone. It is important to note that in practical implementation, large areas of copper should not be laid on top, bottom, or around the antenna, otherwise it will cause magnetic eddy current effects, resulting in severe power loss. Large areas of metal planes or metal components should also be avoided around the coil. Signal lines, power lines, and ground lines must not be drawn in circles or semicircles within or around the antenna area to avoid causing severe power loss due to magnetic field eddy current effects. The precision of NFC antenna circuit components should be controlled within 1% to ensure stable communication distance and resonant point.

[0033] The NFC RF conditioning circuit has an RF resistor R2 at its input, which is electrically connected to the second antenna capacitor bank. The NFC RF conditioning circuit mainly includes an EMC (electromagnetic compatibility) filter circuit and an impedance matching circuit. The EMC filter circuit mainly consists of an LC (passive) low-pass filter circuit, designed to filter out derived high-order harmonics in the transmitted antenna signal, improving normal communication between the reader and the card while reducing electromagnetic interference from the antenna to its accessory circuits. The cutoff frequency of this filter should be designed to be above 15MHz, and inductors should not be placed close together to avoid mutual interference caused by mutual inductance effects. The impedance matching circuit serves two purposes: first, to adjust the resonant frequency of the entire antenna transmitting section to around 13.56MHz, increasing the signal amplitude on the coil and thus benefiting magnetic field radiation; second, to match the resistance of the antenna transmitting circuit to near (equal to) the output resistance of the card reader chip, allowing the antenna to reach its maximum transmission power and improving the reading distance. Optional, such as... Figure 2 and Figure 4 As shown, in the NFC radio frequency conditioning circuit, C9 and C10 are used to adjust the standing wave ratio; C7 and C13 are used to adjust the phase; C3 and L2 form an LC filter to suppress harmonics and filter out the derived higher harmonics in the transmitted antenna signal; C2 and C5 are used to adjust the transmission frequency; and C6 and C12 are used to sample the ASK modulation signal.

[0034] This NFC transceiver is a fully integrated multi-protocol NFC transceiver, integrating encoder, decoder, and data framing functions. It is suitable for NFC initiator operation mode, as well as active and passive target operation modes. The integrated analog front-end (AFE) and multi-protocol data framing support all three NFC operating modes. Its main function is to decode the NFC RF signal and then communicate with the microcontroller via I2C or SPI bus. The transceiver also has an interrupt output pin to wake up the microcontroller and put it into operation. Figure 2 As shown, U1 is an NFC transceiver. In specific implementation, it is important to keep the filter capacitor as close to the chip as possible to effectively filter high-frequency signals; minimize the loops in the wiring ground, so the grounding via should be as close as possible to the component or the ground terminal of U1; the two inductors should be placed at a 90-degree angle, that is, when the first inductor is placed horizontally, the second inductor should be placed vertically, which mainly reduces the coupling between the two inductors.

[0035] The microcontroller is mainly used for: (1) listening to the interrupt signal of the NFC transceiver. When the NFC interrupt signal is valid, the microcontroller enables the system to start working from the sleep state (when not in sleep, it directly receives the decoding signal sent by the NFC transceiver) and starts receiving the decoding signal of the NFC transceiver through the serial bus; (2) when the microcontroller is activated by NFC, it receives the Bluetooth / WIFI configuration information sent by the mobile APP, configures the Bluetooth / WIFI module of the device, and then establishes an electrical connection with the mobile APP; (3) after establishing an electrical connection with the mobile APP, it starts working according to the configuration information such as working mode, device parameters, channel function, and sensor coefficient sent by the mobile APP; (4) according to the configured working mode and device parameters, the device starts to collect data from the sensor, including controlling the sensor signal amplification circuit to set the signal gain, and selecting the corresponding signal chain (such as vibrating wire, voltage, current, etc.) in the multi-signal conditioning circuit through the electronic switch, and at the same time starting the analog-to-digital converter to sample and read the signal; (5) finally, the microcontroller sends the collected sensor data to the remote data cloud platform through the remote wireless communication module, and at the same time backs up the configuration information to the remote cloud platform.

[0036] The data transmission module is a combined Bluetooth / Wi-Fi module, primarily used for near-end mode configuration and data reading between the system and the mobile app. It can also connect to the internet via a local Wi-Fi network for remote data transmission. It receives Bluetooth / Wi-Fi configuration information from the microcontroller and establishes an electrical connection with the mobile app. Figure 5 As shown, the Bluetooth module is electrically connected to the WIFI module through the RF0 and RF1 interfaces, and its internal data interface uses a USB interface to communicate with the microcontroller.

[0037] Sensor signal amplification circuit; used to amplify the sensor signal, improve the signal-to-noise ratio, facilitate subsequent circuit processing, and improve measurement accuracy. Its gain coefficient is controlled by the microcontroller, with a default gain of 1. In practical implementation, a single-ended or differential signal chain configuration can be used, with a gain circuit placed at the very beginning of the signal chain to amplify weak analog signals (such as vibrating wire signals or voltage signals). The gain is configured via the microcontroller, for example, 1, 10, 100, 1000, etc.

[0038] The multi-signal conditioning circuit is primarily responsible for conditioning common industrial analog signals such as vibrating wire, voltage, and current signals. It includes filter and signal processing modules. Different analog signals are switched via analog switches, with the control signals coming from the microcontroller. The analog filter primarily removes interference signals and noise outside the sensor signal bandwidth, as well as high-frequency aliasing interference. An active low-pass filter is used, with a passband cutoff frequency of approximately 4000Hz, covering the highest frequency range of vibrating wire sensors. The voltage signal conditioning circuit conditions externally input voltage signals within a wide range to suit the measurement range of the analog-to-digital converter (ADC), for example, converting a ±10V input voltage signal into a 0–5V voltage signal. The current signal conditioning circuit conditions the signal from an external current sensor into a voltage signal for easy integration into the ADC, for example, converting a common 4–20mA external current signal into a 0–5V voltage signal. These signals are then uniformly connected to the ADC. The filtering circuit consists of a second-order active low-pass filter, used to filter out interference and noise outside the bandwidth of the induced signal. The passband cutoff frequency of the second-order active low-pass filter is 4000Hz, which is the upper limit of the output frequency of the vibrating wire sensor, used to filter out aliasing interference, external electromagnetic interference, and noise above 4000Hz. The filter circuit topology adopts an SK form with a gain of 1, which is highly accurate and has few circuit components. The filter parameters are designed using Chebyshev filter parameters with higher transition band attenuation. Switching between different analog quantities can be achieved using a six-channel multiplexer with differential channels (two lines are simultaneously switched on and off). Its logic control section includes an enable signal and a channel selection signal. The enable signal is provided by the microcontroller. When the enable signal is invalid, the multiplexer completely disconnects the external sensor and the internal measurement circuit. When the enable signal is valid, the multiplexer opens the corresponding differential channel according to the channel selection signal, connecting the external sensor to the corresponding measurement circuit.

[0039] Analog-to-digital converter (ADC); an ADC has multi-channel measurement capabilities, enabling polling-style measurement of the analog signal in each channel, while the sampling rate must meet the signal bandwidth requirements, i.e., satisfy the sampling theorem. It is responsible for converting analog signals into digital signals that can be processed by a microcontroller. The processing of vibrating wire signals involves dynamic sampling, so there are certain requirements for the sampling rate of the ADC, generally requiring above 8Ksps.

[0040] The communication module is a remote wireless communication module: it can adopt a 4G cellular mobile communication module; it is mainly used to realize the function of wirelessly connecting the device to the cloud platform, sending the sensor signals measured by the microcontroller to the remote cloud platform, and at the same time sending the mobile APP configuration information to the remote cloud platform for backup.

[0041] In summary, the NFC-based data acquisition system provided in this application (1) simplifies the pairing process: by combining NFC near-field communication technology with monitoring equipment, users can automatically and quickly pair the device with the mobile APP with a simple "touch" action, which greatly simplifies the traditional wired and wireless configuration process; (2) improves work efficiency: it reduces the time and effort required for on-site personnel to configure the equipment, thereby improving the work efficiency of on-site equipment configuration; (3) enhances user experience: the ease of use of the device is significantly improved, and users no longer need to go through complicated steps to connect and configure the device, thereby enhancing user experience and satisfaction; (4) reduces error rate: due to the simplified configuration process, the complexity of human operation is reduced, thereby reducing the risk of device failure or communication failure caused by configuration errors; (5) improves security: through the security features of NFC technology, the security of the device pairing process is ensured, unauthorized device access is prevented, and the security of the system is enhanced.

[0042] It should be noted that the above implementation process is only to illustrate the feasibility of this application, but it does not mean that the data acquisition system based on NFC electronic tags of this application has only the above implementation processes. On the contrary, as long as the data acquisition system based on NFC electronic tags of this application can be implemented, it can be included in the feasible implementation scheme of this application.

[0043] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A data acquisition system based on NFC electronic tags, characterized in that, The NFC induction module, the microcontroller, the data transmission module, the sensor signal amplification circuit, the multi-signal conditioning circuit, the analog-to-digital converter and the communication module are sequentially and electrically connected. The NFC induction module is electrically connected with the mobile terminal and is used for receiving an induction signal sent by the mobile terminal to wake up the microcontroller. The microcontroller is sequentially and electrically connected with the data transmission module, the sensor signal amplification circuit, the multi-signal conditioning circuit, the analog-to-digital converter and the communication module to send a control signal to each module. The data transmission module is electrically connected with the mobile terminal and the microcontroller and is used for establishing communication with the mobile terminal to realize data transmission. The sensor signal amplification circuit, the multi-signal conditioning circuit and the analog-to-digital converter are sequentially and electrically connected, and the sensor signal amplification circuit is used for amplifying the collected sensor signal to improve the signal-to-noise ratio. The multi-signal conditioning circuit is electrically connected with the sensor signal amplification circuit and is used for analog switching of the amplified sensor signal. The communication module is electrically connected with the microcontroller and the cloud platform and is used for sending the processed sensor signal and the configuration information of the mobile terminal to the remote cloud platform.

2. The NFC electronic tag based data acquisition system according to claim 1, wherein, The NFC induction module includes an NFC antenna, an NFC radio frequency conditioning circuit and an NFC transceiver which are sequentially and electrically connected.

3. The NFC electronic tag based data acquisition system of claim 2, wherein, The NFC antenna includes a first antenna capacitor group and a second antenna capacitor group which are electrically connected.

4. The NFC electronic tag based data acquisition system of claim 3, wherein, The first antenna capacitor group includes a plurality of parallel first antenna capacitors and a parallel adjustment resistor.

5. The NFC electronic tag based data acquisition system of claim 4, wherein, The second antenna capacitor group includes a plurality of parallel second antenna capacitors.

6. The NFC electronic tag based data acquisition system of claim 5, wherein, The input end of the NFC radio frequency conditioning circuit is provided with a radio frequency resistor which is electrically connected with the second antenna capacitor group. The NFC radio frequency conditioning circuit includes an EMC filter circuit and an impedance matching circuit. The EMC filter circuit includes an adjustment standing wave ratio capacitor, an adjustment phase capacitor, an adjustment transmission frequency capacitor and a sampling ASK modulation signal capacitor which are electrically connected. The impedance matching circuit includes an LC filter composed of a filter capacitor and a filter inductor. The TX input interface of the NFC transceiver is electrically connected with the adjustment transmission frequency capacitor. The NFC transceiver includes at least two vertically placed inductors to reduce the coupling between the inductors.

7. The NFC electronic tag based data acquisition system as claimed in claim 1, wherein, The data transmission module is a Bluetooth / WIFI module two-in-one transmission module, wherein the Bluetooth module is electrically connected with the WIFI module through RF0 and RF1 interfaces.

8. The NFC electronic tag based data acquisition system according to claim 1, wherein, The gain coefficient of the sensor signal amplification circuit is controlled by the microcontroller.

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