Internet of Things wireless collector based on narrowband spread spectrum technology

Abstract

The invention discloses an Internet of Things wireless collector based on a narrowband spread spectrum technology, which comprises a shell and a rear cover plate, and is characterized in that the shell is provided with a quick connector, a standard external antenna screw and a wireless collection module; the quick connector is used for being externally connected with a power line and an RS-485 communication line. The standard external antenna screw socket is used for installing an external antenna; the wireless acquisition module is connected with an external antenna through an RS-485 communication line, is connected with a power supply through a power line, and is used for acquiring wireless signals received by the external antenna. According to the invention, the number supported by the collector can reach 254 at most, and the one-to-many wireless gateway based on LoRa generally only supports less than 10 wireless terminals. Meanwhile, the cost of the collector is lower than that of a one-to-many wireless gateway based on LoRa by more than 50%, and the collector has high economic value.

Description

Technical Field

[0001] The present invention belongs to the field of wireless acquisition technology, and in particular relates to an Internet of Things wireless collector based on narrowband spread spectrum technology. Background Art

[0002] In IoT application scenarios, short-range wireless communication within 500 meters is very common, which can effectively solve various wired transmission problems such as long wiring time, high cost, and damage to the original decoration.

[0003] However, in the existing technologies, wireless radio frequency, Bluetooth, LoRa, WiFi and other technologies have all been maturely applied.

[0004] The effective communication distance of wireless radio frequency and Bluetooth technology is short, and the disadvantage is obvious

[0005] LoRa is widely used. LoRa is a low-power LAN wireless standard developed by Semtech. Its name "LoRa" stands for Long Range Radio. Its biggest feature is that it can transmit farther than other wireless methods under the same power consumption conditions, achieving the unity of low power consumption and long distance. It can extend the communication distance 3-5 times that of traditional wireless radio frequency under the same power consumption.

[0006] However, LoRa is more mature in point-to-point wireless communication, while point-to-multipoint star connection is less used and has a higher cost.

[0007] The widespread coverage of WiFi has also enabled more and more IoT devices to achieve long-distance wireless communication within campuses or buildings through WiFi. However, WiFi networks are usually deployed in relatively small areas, such as in some rooms, or in buildings, across buildings or in open areas outdoors, and WiFi signal coverage is still weak. At the same time, connecting too many IoT devices also occupies network resources, affecting the regular network transmission needs of other computer devices in WiFi.

[0008] Therefore, a wireless communication device with low cost, long communication distance, one-to-many communication and relatively independent network resources is needed to solve the above problems and provide a new and more cost-effective solution for wireless remote meter reading and wireless remote centralized control. Summary of the invention

[0009] In order to solve the above technical problems, the present invention proposes an Internet of Things wireless collector based on narrowband spread spectrum technology to solve the problems existing in the above prior art.

[0010] To achieve the above object, the present invention provides an Internet of Things wireless collector based on narrowband spread spectrum technology, comprising:

[0011] A housing and a rear cover, wherein the housing is provided with a quick connector, a standard external antenna screw port and a wireless acquisition module;

[0012] The quick connector is used for external power line and RS-485 communication line;

[0013] The standard external antenna screw hole is used to install an external antenna;

[0014] The wireless acquisition module is connected to the external antenna via an RS-485 communication line and is connected to a power source via the power line, and is used to acquire wireless signals received by the external antenna.

[0015] Preferably, the external antenna includes a rubber stick antenna and a suction cup antenna.

[0016] Preferably, during operation, the wireless acquisition module is divided into a master collector, a slave collector and a wireless acquisition module; the master collector communicates with a terminal wireless device, and the terminal wireless device includes a slave collector and a device equipped with a wireless acquisition module.

[0017] Preferably, the wireless acquisition module includes an MCU, a narrowband spread spectrum wireless chip, an AC-DC power supply module and a filter capacitor, and the MCU, the narrowband spread spectrum wireless chip, the AC-DC power supply module and the filter capacitor are integrated on a circuit board.

[0018] Preferably, the AC-DC power supply module comprises:

[0019] An input terminal for receiving alternating current;

[0020] Varistor, connected between the live wire and the ground wire, for overvoltage protection;

[0021] a thermistor, connected in parallel with the varistor, for suppressing the inrush current during startup;

[0022] A transformer, wherein the primary coil of the transformer is connected between the live wire and the ground wire, and the secondary coil output is connected to a rectifier bridge for voltage conversion;

[0023] A rectifier bridge, used to convert AC into pulsating DC;

[0024] A filter capacitor connected to the rectifier bridge for smoothing the rectified pulsating direct current;

[0025] A voltage stabilizer, connected to the filter capacitor, for providing a stable DC output;

[0026] An output capacitor, connected between the output of the regulator and ground, is used to further smooth the output of the regulator;

[0027] Schottky diode, connected between the output and input of the regulator to block reverse current;

[0028] The output terminal is connected to the voltage regulator and is used to provide a stable voltage.

[0029] Preferably, the communication circuit connected by the RS-485 communication line includes:

[0030] RS-485 transceiver, wherein the RS-485 transceiver includes a TPT485E-SO1R chip;

[0031] Power decoupling capacitor, used for power decoupling and reducing power noise;

[0032] Terminal resistors are used to provide terminal matching at both ends of the RS-485 communication line to reduce signal reflection;

[0033] Current limiting resistor, used to limit the current flowing through the PTC resettable fuse;

[0034] PTC resettable fuse, used for overcurrent protection;

[0035] TVS diodes are used to remove the impact of voltage spikes on protection circuits;

[0036] Test points, used for measurement or debugging;

[0037] RS-485 interface, used to connect to external RS-485 network.

[0038] Preferably, the housing is also provided with a maintenance interface for maintaining the Internet of Things wireless collector.

[0039] Compared with the prior art, the present invention has the following advantages and technical effects:

[0040] The present invention discloses an Internet of Things wireless collector based on narrowband spread spectrum technology, including: a shell and a rear cover, the shell is provided with a quick connector, a standard external antenna screw and a wireless acquisition module; the quick connector is used for an external power line and an RS-485 communication line; the standard external antenna screw is used to install an external antenna; the wireless acquisition module is connected to the external antenna through the RS-485 communication line, and is connected to the power supply through the power line, and is used to collect wireless signals received by the external antenna. The collector of the present invention supports a maximum of 254 and a long communication distance, while a one-to-many wireless gateway based on LoRa generally only supports less than 10 wireless terminals. At the same time, the cost of the collector of the present invention is more than 50% lower than that of a one-to-many wireless gateway based on LoRa, and has a high economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0042] Figure 1 This is a schematic diagram of the application of a wireless collector according to an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of the components of a wireless collector according to an embodiment of the present invention;

[0044] Figure 3 This is a front view of the wireless acquisition module according to an embodiment of the present invention;

[0045] Figure 4 This is a physical picture of the back of the wireless acquisition module according to an embodiment of the present invention;

[0046] Figure 5 is an AC-DC circuit diagram of an embodiment of the present invention;

[0047] Figure 6 The RS-485 circuit diagram of an embodiment of the present invention is as follows;

[0048] Figure 7 A DC-DC circuit diagram of an embodiment of the present invention;

[0049] Figure 8 A circuit diagram of a maintenance interface according to an embodiment of the present invention;

[0050] Fig. 9 FIG. 4 is a circuit diagram of a wireless module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0052] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0053] Embodiment 1

[0054] like Figure 2 As shown, this embodiment provides an Internet of Things wireless collector based on narrowband spread spectrum technology, including:

[0055] The outer shell and the rear cover are provided with a quick connector, a standard external antenna screw and a wireless acquisition module;

[0056] Quick connector is used for external power line and RS-485 communication line;

[0057] The standard external antenna screw port is used to install the external antenna;

[0058] The wireless acquisition module is connected to the external antenna via an RS-485 communication line and is connected to the power supply via a power line, and is used to collect wireless signals received by the external antenna.

[0059] Application scenarios of the device Figure 1 As shown in the figure, the core functional module is the wireless acquisition module. Figure 3 , Figure 4 As shown, specifically including:

[0060] 1. The collector housing and rear cover are made of PVC insulation and flame retardant material, which is safe and light, and can be installed with snap-on buckles, eliminating the need for screw fixing. At the same time, the rear cover is designed with rail mounting buckles, which can be directly installed on the standard rail.

[0061] 2. The collector is equipped with a quick connector to organically integrate the external power cord (220V mains power) and RS485 communication line. The extension cord is also equipped with a quick connector for easy plugging, eliminating the trouble of repeatedly disassembling and assembling the power cord and RS485 line after connecting to the wiring terminals of the gateway and other collection equipment.

[0062] 3. The collector is equipped with a standard external antenna screw port, which is a rubber stick antenna as standard. It can also be directly replaced with a suction cup antenna according to the installation environment to expand the communication range and improve the communication success rate.

[0063] 4. The core component of the collector, the wireless acquisition module (hereinafter referred to as the "wireless acquisition module"), is equipped with an MCU, a narrowband spread spectrum wireless chip, an AC-DC power module, a filter capacitor, etc., to realize whitelist management, Mod Bus full transparent transmission, RS485 data uplink, wireless data downlink, one-to-many acquisition and other functions. The AC-DC power module converts the external 220V pilot into a 3.3V DC power supply to power the module.

[0064] 5. Wireless collectors are divided into three forms: master collectors, slave collectors, and wireless collection modules. A master collector can communicate with 254 terminal wireless devices at the same time. The terminal wireless devices include multiple slave collectors and multiple devices equipped with wireless collection modules (such as wireless air conditioning controllers, wireless temperature sensors, etc.). Typical application scenarios include:

[0065] (1) Remote meter reading: The master collector is connected to the upper collection device (including edge computing gateway, computer, etc.) through RS485, and the slave collector is connected to the lower smart electricity meter, smart water meter, smart gas meter, remote flow meter and other devices with remote transmission function through RS485. Wireless transmission is carried out between the master and slave collectors.

[0066] (2) Remote centralized control: The main collector collects data and issues control instructions through wireless communication with the air-conditioning controller and temperature sensor, realizing remote collection of ambient temperature and humidity and remote intelligent control of split air conditioners.

[0067] Furthermore, the AC-DC power module circuit is as follows Figure 5 As shown, including:

[0068] Input:

[0069] TP_N1 and TP_L2 are the input terminals of AC power, representing the neutral line (N) and live line (L) of AC power respectively.

[0070] Varistor (RV1):

[0071] RV1 is a varistor, model MYN23-681K, used for overvoltage protection. It is connected between TP_L2 and ground.

[0072] Thermistor (RT1):

[0073] RT1 is a thermistor, model NTC10D9S, used to suppress the inrush current at startup. It is connected in parallel with RV1.

[0074] Transformer (T1):

[0075] T1 is a transformer, model QY28-20A6, used for voltage conversion. Its primary coil is connected between TP_L2 and ground, and the secondary coil output is connected to the rectifier bridge.

[0076] Rectifier bridge (BR1):

[0077] BR1 is a rectifier bridge, model MB10S, used to convert AC power into pulsating DC power. It is connected between the secondary output of the transformer and the filter capacitor C2.

[0078] Filter capacitor (C2):

[0079] C2 is an electrolytic capacitor, model SMBJ24CA 35V / 1000uF, used to smooth the pulsating DC after rectification. It is connected between the output of the rectifier bridge and the input of the regulator V1.

[0080] Voltage Regulator (V1):

[0081] V1 is a linear regulator, model 78L05, used to provide a stable 5V DC output. It is connected between the filter capacitor C2 and the output terminal V5P0.

[0082] Output capacitor (C3):

[0083] C3 is a ceramic capacitor, 4.7uF / 50V, used to further smooth the output of the regulator. It is connected between the output of the regulator and ground.

[0084] Schottky diode (V4):

[0085] V4 is a Schottky diode, model B5819W, used to prevent reverse current. It is connected between the output and input of the regulator.

[0086] Output terminal (TP2):

[0087] TP2 is the DC output terminal, providing a stable 5V voltage.

[0088] The working principle of the whole circuit is: after the AC passes through the varistor and thermistor, it enters the transformer for voltage conversion, and then is converted into pulsating DC through the rectifier bridge. After being smoothed by the filter capacitor, the voltage regulator provides a stable DC output, and finally the Schottky diode is used to prevent reverse current, and the output end provides a stable 5V DC.

[0089] Furthermore, the communication circuit connected by the RS-485 communication line is as follows Figure 6 include:

[0090] RS-485 transceiver:

[0091] The chip used is the TPT485E-SO1R, which is a low-power RS-485 transceiver packaged as SO8.

[0092] Pin 1 (D) and pin 2 (DE) are used for data transmission control, where the DE pin is used to enable the transmit mode.

[0093] Pin 3 (RE) is used to enable receive mode.

[0094] Pin 4 (GND) is ground.

[0095] Pin 5 (B) and pin 6 (A) are differential signal lines, corresponding to the A line and B line of RS-485 respectively.

[0096] Pin 7 (R) and pin 8 (VCC) are used to receive data and provide power, respectively.

[0097] Power supply decoupling capacitors:

[0098] C1 is a 0.1uF / 16V capacitor used for power supply decoupling and reducing power supply noise.

[0099] Terminal resistance:

[0100] R1 and R3 are 10kΩ pull-up resistors used to provide terminal matching at both ends of the RS-485 bus to reduce signal reflections.

[0101] Current limiting resistor:

[0102] R2 is a 10Ω current limiting resistor used to limit the current flowing through the PTC resettable fuse.

[0103] PTC resettable fuse:

[0104] F1 is a PTC resettable fuse of model MZ11-13P15RH265, used for overcurrent protection. When the current exceeds a certain value, the PTC will quickly increase the resistance, limit the current, and thus protect the circuit.

[0105] TVS diode:

[0106] V3 is a P0080SB TVS (Transient Voltage Suppression) diode used to protect the circuit from voltage spikes.

[0107] Test points:

[0108] TP1 and TP_II are test points for measurement or debugging.

[0109] RS-485 interface:

[0110] RS485A1 / A2 and RS485B1 / B2 are the pins of the RS-485 communication interface, used to connect to an external RS-485 network.

[0111] The entire circuit is designed to implement RS-485 communication, providing the necessary power decoupling, terminal matching, over-current protection, and voltage protection to ensure the stability and reliability of communication.

[0112] Furthermore, a maintenance interface is provided on the shell for maintaining the IoT wireless collector.

[0113] Maintenance interface circuit such as Figure 8 As shown, including:

[0114] Connector J1:

[0115] J1 is a 5-pin HDR1x5 connector for connecting external devices or programmers.

[0116] Pin 1 is connected to the 3.3V power supply.

[0117] Pin 2 is connected to ground (GND).

[0118] Pin 3 and pin 4 are connected to 3.3V via resistors R31 and R32 respectively, these resistors may be used for pull-ups or current limiting.

[0119] Pin 5 is connected to the reset signal (RST).

[0120] Decoupling capacitors:

[0121] C21 and C24 are 0.1uF / 50V decoupling capacitors used to stabilize the 3.3V power supply and reduce power supply noise.

[0122] Pull-up resistor:

[0123] R31, R32, and R33 are 10kΩ pull-up resistors used to ensure that the pin remains at a high level when there is no external signal.

[0124] Pull-down resistor:

[0125] R34, R35 and R36 are 22Ω pull-down resistors used to ensure that the pin remains at a low level when there is no external signal.

[0126] SWD Interface:

[0127] XS1 is a 5-pin SWD (Serial Wire Debug) interface used for MCU programming and debugging.

[0128] Pin 1 is connected to ground (GND).

[0129] Pin 2 is connected to UART2_TX for sending debug data.

[0130] Pin 3 is connected to UART2_RX for receiving debug data.

[0131] Pin 4 is connected to MCU_MD and may be used for mode selection or control signals.

[0132] Pin 5 is connected to the 3.3V power supply.

[0133] UART interface:

[0134] UART2_TX and UART2_RX are used for sending and receiving serial communication respectively.

[0135] Reset circuit:

[0136] The RST pin is connected to 3.3V through a resistor and is used to reset the MCU.

[0137] Decoupling capacitor C23:

[0138] C23 is a 0.1uF / 50V decoupling capacitor used to stabilize the power supply of the SWD interface.

[0139] The entire circuit is designed to provide the programming and debugging interface of the MCU, including power decoupling, signal pull-up / pull-down, and SWD communication interface. Such a design can ensure the stability and reliability of the MCU during development and maintenance.

[0140] The MCU of the present invention is provided with a DC-DC buck converter circuit, such as Figure 7 As shown, it is used to convert the higher input voltage (V15P0) into a stable 3.3V output. The following is an analysis of the various parts of the circuit:

[0141] Input capacitors (C5 and C6):

[0142] C5 is a 0.1uF / 50V capacitor, which is used to decouple the input voltage and reduce power supply noise.

[0143] C6 is a 10uF / 25V capacitor used to smooth the input voltage and provide a stable power supply.

[0144] Resistor divider (R8 and R10):

[0145] R8 is a 100kΩ resistor and R10 is a 47kΩ resistor that form a voltage divider to set the output voltage of the DC-DC converter.

[0146] DC-DC Converter (U1):

[0147] U1 is a RY2400 DC-DC converter with SO123-6 package.

[0148] The EN pin (pin 4) is used to enable the converter and is connected to the input voltage through R8 and to ground through R10, forming a voltage divider circuit to control the output voltage.

[0149] The IN pin (pin 5) is the input voltage terminal.

[0150] The FB pin (Pin 3) is the feedback pin and is used to regulate the output voltage.

[0151] The LX pin (Pin 6) is the switching node for connecting the inductor.

[0152] The GND pin (pin 2) is connected to ground.

[0153] Inductor (L3):

[0154] L3 is a 6.8uH inductor used for energy storage and filtering to smooth the output current.

[0155] Output capacitors (C7, C8 and C9):

[0156] C7 is a 47pF / 50V capacitor used for high frequency decoupling.

[0157] C8 is a 22uF / 6.3V capacitor used to smooth the output voltage.

[0158] C9 is a 10uF / 6.3V capacitor used to further smooth the output voltage.

[0159] Compensation Network (R1, R9 and C7):

[0160] R1 is a 100kΩ resistor and R9 is a 100Ω resistor, which together with C7 form a compensation network for stabilizing the control loop of the converter.

[0161] Feedback resistor (R2):

[0162] R2 is a 31.6kΩ resistor used to set the output voltage of the converter. According to the formula in the picture, the output voltage Vout can be set by adjusting the value of R2.

[0163] Output voltage:

[0164] According to the formula in the picture, the output voltage Vout can be set by adjusting the value of R2. Under the current setting, the output voltage is about 3.332V.

[0165] The entire circuit is designed to convert the input voltage into a stable 3.3V output, which is suitable for electronic devices that require precise voltage power supply. The various components in the circuit work together to ensure the stability of the output voltage and conversion efficiency.

[0166] like Fig. 9 As shown, the present invention also proposes a wireless module circuit, including:

[0167] Power supply:

[0168] The 3.3V power supply (marked as 3V3D) provides operating voltage for the wireless module.

[0169] Current limiting resistor (B2):

[0170] B2 is a 120Ω current limiting resistor, which is used to limit the current flowing through capacitor C22 and protect the circuit.

[0171] Decoupling capacitor (C22):

[0172] C22 is a 0.1uF / 50V capacitor used for power supply decoupling and reducing power supply noise.

[0173] Wireless module (J2):

[0174] J2 is the connector of the wireless module, model number is DTM-CC001D, KM-1110.

[0175] Pin 1 and Pin 13 are connected to ground (GND).

[0176] Pin 5 provides the VCC voltage.

[0177] Pins 6, 7, 8, 9, 10, and 11 are used for SPI communication, including SPI1_SCK (clock), SPI1_CSN (chip select), SPI1_MISO (master input slave output), and SPI1_MOSI (master output slave input).

[0178] Pin 12 is the IRQ (Interrupt Request) pin.

[0179] Pin 14 is the ANT (antenna) pin, which is used for sending and receiving wireless signals.

[0180] Antenna interface (D3):

[0181] D3 is a WPE5V0D3ULA model antenna interface used to connect an external antenna.

[0182] Connector J3:

[0183] J3 is a 2-pin connector for analog signal input (ANA).

[0184] The entire circuit is designed to implement wireless communication functions, providing the necessary power decoupling, SPI communication interface, and antenna connection. Such a design can be used in various embedded systems that require wireless communication, such as smart home devices, wireless sensor networks, etc.

[0185] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An Internet of Things wireless collector based on narrowband spread spectrum technology, characterized in that: include: A housing and a rear cover, wherein the housing is provided with a quick connector, a standard external antenna screw port and a wireless acquisition module; The quick connector is used for external power line and RS-485 communication line; The standard external antenna screw hole is used to install an external antenna; The wireless acquisition module is connected to the external antenna via an RS-485 communication line and is connected to a power source via the power line, and is used to acquire wireless signals received by the external antenna.

2. According to claim 1, the Internet of Things wireless collector based on narrowband spread spectrum technology is characterized in that: The external antenna includes a rubber stick antenna and a suction cup antenna.

3. According to claim 1, the Internet of Things wireless collector based on narrowband spread spectrum technology is characterized in that: During operation, the wireless acquisition module is divided into a main collector, a slave collector and a wireless acquisition module; the main collector communicates with a terminal wireless device, and the terminal wireless device includes a slave collector and a device equipped with a wireless acquisition module.

4. According to claim 1, the wireless collector for Internet of Things based on narrowband spread spectrum technology is characterized in that: The wireless acquisition module includes an MCU, a narrow-band spread spectrum wireless chip, an AC-DC power supply module and a filter capacitor, and the MCU, the narrow-band spread spectrum wireless chip, the AC-DC power supply module and the filter capacitor are integrated on a circuit board.

5. According to claim 4, the Internet of Things wireless collector based on narrowband spread spectrum technology is characterized in that: The AC-DC power supply module comprises: An input terminal for receiving alternating current; Varistor, connected between the live wire and the ground wire, for overvoltage protection; a thermistor, connected in parallel with the varistor, for suppressing the inrush current during startup; A transformer, wherein the primary coil of the transformer is connected between the live wire and the ground wire, and the secondary coil output is connected to a rectifier bridge for voltage conversion; A rectifier bridge, used to convert AC into pulsating DC; A filter capacitor connected to the rectifier bridge for smoothing the rectified pulsating direct current; A voltage stabilizer, connected to the filter capacitor, for providing a stable DC output; An output capacitor, connected between the output of the regulator and ground, is used to further smooth the output of the regulator; Schottky diode, connected between the output and input of the regulator to block reverse current; The output terminal is connected to the voltage regulator and is used to provide a stable voltage.

6. According to claim 1, the wireless collector for Internet of Things based on narrowband spread spectrum technology is characterized in that: The communication circuit connected by RS-485 communication line includes: RS-485 transceiver, wherein the RS-485 transceiver includes a TPT485E-SO1R chip; Power decoupling capacitor, used for power decoupling and reducing power noise; Terminal resistors are used to provide terminal matching at both ends of the RS-485 communication line to reduce signal reflection; Current limiting resistor, used to limit the current flowing through the PTC resettable fuse; PTC resettable fuse, used for overcurrent protection; TVS diodes are used to remove the impact of voltage spikes on protection circuits; Test points, used for measurement or debugging; RS-485 interface, used to connect to external RS-485 network.

7. According to claim 1, the wireless collector for Internet of Things based on narrowband spread spectrum technology is characterized in that: The housing is also provided with a maintenance interface for maintaining the Internet of Things wireless collector.

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