Fall detection system based on embedded microprocessor

Abstract

The utility model discloses a tumble detection system based on an embedded microprocessor, which relates to the technical field of software and hardware system design and comprises the embedded microprocessor, a Bluetooth module, a millimeter wave radar module and a wireless WIFI (wireless fidelity) module. The main control chip is connected with the Bluetooth module, the millimeter wave radar module and the wireless WIFI module, and the main control chip adopts an STM32F103C8T6 chip. According to the utility model, the problems of high false alarm rate, high detection cost and privacy leakage of the existing detection method are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of software and hardware system design, and in particular to a fall detection system based on an embedded microprocessor. Background Art

[0002] Falls have a high incidence and serious health impacts, and are particularly common among the elderly. As they age, the elderly's physical functions gradually decline, including weakened muscle strength, decreased balance, and decreased vision and hearing. These physiological factors increase the risk of falls in the elderly. Unsafe factors in the home and community environment, such as uneven floors, improperly placed furniture, and insufficient lighting, can also increase the likelihood of falls. Falls can not only cause physical injuries, but can also affect an individual's psychological and social functions, seriously affecting their quality of life and health. Therefore, preventing falls and taking emergency measures to protect individual health and safety are crucial and deserve high attention.

[0003] Currently, fall detection relies primarily on smart bracelets or cameras. Smart bracelets are small, easy to wear, and offer high detection sensitivity, but they can't be worn at all times, especially at night. Furthermore, smart bracelets often rely on built-in accelerometers to detect falls. However, sudden hand movements can be mistakenly identified as falls, leading to a high false alarm rate. Furthermore, smart bracelets can only detect hand movements and cannot fully determine whether a fall has occurred. This is especially true if a fall occurs outside the wristband's wearable area, which can go undetected. Camera detection is costly and may raise privacy concerns. Camera detection requires real-time monitoring of user activity, which some users may be reluctant to install in their homes or public places. Camera-based fall detection typically requires good lighting and a clear image. Poor ambient conditions, such as low light or a restricted camera field of view, can affect fall detection accuracy. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a fall detection system based on an embedded microprocessor, which solves the problems of high false alarm rate, high detection cost and privacy leakage in the existing detection methods.

[0005] In order to achieve the above-mentioned purpose of the invention, the technical solution adopted by the present invention is: a fall detection system based on an embedded microprocessor, including an embedded microprocessor, a Bluetooth module, a millimeter-wave radar module and a wireless WIFI module. The embedded microprocessor serves as the main control chip and is respectively connected to the Bluetooth module, the millimeter-wave radar module and the wireless WIFI module. The main control chip adopts the STM32F103C8T6 chip.

[0006] Furthermore, the main control chip U2 is connected to the millimeter-wave radar module through pins PA9 and PA10. Pin PA9 of the main control chip U2 is connected to the emitter of the transistor Q3. The base of the transistor Q3 is connected to one end of the resistor R12. The collector of the transistor Q3 is respectively connected to one end of the resistor R13 and the pin RX of the chip U1 in the millimeter-wave radar module. The model of the chip U1 is R60AFD1. The other end of the resistor R12 and the other end of the resistor R13 are both connected to the power supply.

[0007] Pin PA10 of the main control chip U2 is respectively connected to one end of the resistor R16 and the collector of the transistor Q4, the other end of the resistor R16 is connected to the power supply, the emitter of the transistor Q4 is grounded, the base of the transistor Q4 is connected to one end of the resistor R15, the other end of the resistor R15 is respectively connected to one end of the resistor R14 and the collector of the transistor Q5, the other end of the resistor R14 is connected to the power supply, the emitter of the transistor Q5 is grounded, the base of the transistor Q5 is connected to one end of the resistor R17, the other end of the resistor R17 is connected to the pin TX of the chip U1 in the millimeter wave radar module, the pin 1 of the chip U1 is respectively connected to the power supply and the grounding capacitor C34, and the pin 4 of the chip U1 is grounded.

[0008] Furthermore, the main control chip U2 is connected to the wireless WIFI module through pins PA2 and PA3, the pin PA2 of the main control chip U2 is connected to one end of the resistor R25, and the other end of the resistor R25 is connected to the pin RXD of the chip U6. The chip U6 model is ESP-12F, the pin RST of the chip U6 is connected to one end of the resistor R18, the pin EN of the chip U6 is connected to one end of the resistor R19, the other end of the resistor R18 and the other end of the resistor R19 are both connected to the power supply, the pin VCC of the chip U6 is respectively connected to the power supply and the grounding capacitor C12, the pin IO0 of the chip U6 is connected to one end of the resistor R20, and the other end of the resistor R20 is connected to the grounding resistor R23, the pin IO2 of the chip U6 is connected to one end of the resistor R22, and the other end of the resistor R22 is connected to the power supply, and the pin IO15 of the chip U6 is connected to the grounding resistor R21;

[0009] The pin PA3 of the main control chip U2 is connected to one end of the resistor R24, and the other end of the resistor R24 ​​is connected to the pin TXD of the chip U6.

[0010] Furthermore, the main control chip U2 is connected to the Bluetooth module through pins PB10 and PB11. The pin PB10 of the main control chip U2 is connected to one end of the resistor R27, and the other end of the resistor R27 is connected to the pin RXD of the chip U7. The model of the chip U7 is HC-08. The pin PB11 of the main control chip U2 is connected to one end of the resistor R26, and the other end of the resistor R26 is connected to the pin TXD of the chip U7. The pin GND of the chip U7 is grounded, and the pin 3V3 of the chip U7 is respectively connected to the grounding capacitor C35 and the power supply.

[0011] Furthermore, the pin PC13-TAMPER-RTC of the main control chip U2 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the cathode of the light-emitting diode LED2, the anode of the light-emitting diode LED2 is connected to the power supply, the power supply is also connected to the anode of the light-emitting diode LED1, and the cathode of the light-emitting diode LED1 is connected to the ground resistor R6;

[0012] The fall detection system further includes a crystal oscillator circuit, which includes a crystal oscillator X1, a capacitor C14, and a capacitor C16. The pin PD0-OSC_IN of the main control chip U2 is connected to the grounded capacitor C14 and one end of the crystal oscillator X1, respectively. The pin PD1-OSC_OUT of the main control chip U2 is connected to the grounded capacitor C16 and the other end of the crystal oscillator X1, respectively.

[0013] The fall detection system further includes a reset circuit, which includes a switch SW1, a capacitor C1, and a resistor R7. The pin NRST of the main control chip U2 is connected to one end of the resistor R7, the grounded capacitor C1, and the port 1 of the switch SW1, respectively. The other end of the resistor R7 is connected to the power supply, and the port 2 of the switch SW1 is grounded.

[0014] The fall detection system also includes a download circuit, which includes a connector P1, a resistor R1, a resistor R2, a resistor R3, and a resistor R4. The pin PA13 of the main control chip U2 is connected to one end of the resistor R2, and the other end of the resistor R2 is respectively connected to one end of the resistor R1 and port 2 of the connector P1. The model of the connector P1 is HEADER_1*4P. The other end of the resistor R1 is respectively connected to the power supply and port 1 of the connector P1. The port 3 of the connector P1 is respectively connected to one end of the grounding resistor R3 and the resistor R4. The other end of the resistor R4 is connected to the pin PA14 of the main control chip U2. Port 4 of the connector P1 is grounded.

[0015] The fall detection system also includes a radar switch circuit, which includes a transistor Q1, a transistor Q2, a resistor R9, a resistor R10, a resistor R11, a capacitor C23, a capacitor C24 and a capacitor C25. The pin PB4 of the main control chip U2 is connected to one end of the resistor R10, and the other end of the resistor R10 is respectively connected to the ground resistor R11 and the base of the transistor Q2. The emitter of the transistor Q2 is grounded, and the collector of the transistor Q3 is respectively connected to the base of the transistor Q1 and one end of the resistor R9. The emitter of the transistor Q1 and the other end of the resistor R9 are both connected to a power supply. The collector of the transistor Q1 is respectively connected to the ground capacitor C23, the ground capacitor C24, the ground capacitor C25 and an external 5V power supply VCC_5V_R;

[0016] The fall detection system further includes a BOOT circuit, the BOOT circuit including a resistor R8, and the pin BOOT0 of the main control chip U2 is connected to the ground capacitor R8;

[0017] The fall detection system further includes a power supply circuit, which includes an external power supply USB1, wherein a VCC pin of the external power supply USB1 is respectively connected to a power supply, a grounding capacitor C17, a grounding capacitor C10, a grounding capacitor C18, and a grounding capacitor C19, and a GND pin and an EP pin of the external power supply USB1 are both grounded;

[0018] The fall detection system also includes a step-down circuit, which includes a chip U4. The model of the chip U4 is SGM2036-3.3YN5G / TR. The IN pin of the chip U4 is respectively connected to its EN pin, the power supply and the ground capacitor C20. The GND pin of the chip U4 is grounded. The OUT pin of the chip U4 is respectively connected to the power supply and the ground capacitor C21. The BP / FP pin of the chip U4 is connected to the ground capacitor C22.

[0019] The fall detection system also includes an inductor L1, a grounding capacitor C26, a grounding capacitor C27, a grounding capacitor C28, a grounding capacitor C29, a grounding capacitor C30, a grounding capacitor C31, a grounding capacitor C32, and a grounding capacitor C33. Both ends of the inductor L1 are connected to a power supply, and the grounding capacitors C26, C27, C28, C29, C30, C31, C32, and C33 are all connected to a power supply.

[0020] Furthermore, the embedded microprocessor, Bluetooth module, millimeter-wave radar module and wireless WIFI module are integrated on a PCB board, and the PCB board is placed inside a hardware circuit board shell. The hardware circuit board shell is made of LEDO 6060SLA photosensitive and resin materials, and the surface is polished. The size of the hardware circuit board shell is 0.5*5.48*6.43cm.

[0021] Furthermore, the Bluetooth module adopts a data transmission module based on the Bluetooth Specification V4.0 BLE Bluetooth protocol, and the wireless operating frequency band is 2.4GHz ISM.

[0022] Furthermore, the core processor of the wireless WIFI module is ESP8266.

[0023] The beneficial effects of the present utility model are: using the data capture and data transmission capabilities of the millimeter wave radar and wireless module to improve the fall detection method and enhance the detection effect. By automatically detecting the body motion parameters in the current spatial environment through computers and hardware equipment, it is further determined whether there is a human body and whether a fall has occurred. This greatly simplifies the fall detection process, reduces the difficulty of detection, reduces the risk after a fall occurs, and saves a lot of labor. At the same time, the detection system adopted in this solution can detect human falls and other behaviors in a more efficient, accurate and intelligent manner, providing an effective solution for preventing human falls and other situations, further ensuring human safety, and enhancing the reliability and security of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the schematic diagram of the embedded microprocessor circuit.

[0025] Figure 2 This is the circuit schematic diagram of the millimeter wave radar module.

[0026] Figure 3 This is the circuit schematic diagram of the wireless WIFI module.

[0027] Figure 4 This is the schematic diagram of the Bluetooth module circuit.

[0028] Figure 5 This is the schematic diagram of the reset circuit, crystal oscillator circuit, download circuit and radar switch circuit.

[0029] Figure 6 This is the schematic diagram of the BOOT circuit, power supply circuit and voltage drop circuit.

[0030] Figure 7 This is the top-level schematic diagram of the PCB board.

[0031] Figure 8 This is the bottom schematic diagram of the PCB board.

[0032] Figure 9 This is a structural diagram of the shell on the radar side of the hardware circuit board.

[0033] Figure 10 This is a diagram of the shell structure on the back side of the hardware circuit board. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] A fall detection system based on an embedded microprocessor includes an embedded microprocessor, a Bluetooth module, a millimeter-wave radar module, and a wireless WiFi module. The embedded microprocessor serves as a main control chip and is respectively connected to the Bluetooth module, the millimeter-wave radar module, and the wireless WiFi module. The main control chip adopts an STM32F103C8T6 chip.

[0036] The embedded microprocessor used in this utility model features a rich set of peripherals and functions, including an analog-to-digital converter (ADC), timers, serial communication interfaces (USART, SPI, I2C), general-purpose timers, and a PWM controller. It also utilizes a Harvard Architecture that separates instruction and data storage, with independent 32-bit instruction and data buses. Data access does not occupy the instruction bus, and simultaneous access to instructions and data increases MCU speed. It also supports low-power modes and provides a wealth of development tools and support resources to facilitate application development.

[0037] like Figure 1 and Figure 2 As shown, the main control chip U2 is connected to the millimeter-wave radar module through pins PA9 and PA10. The pin PA9 of the main control chip U2 is connected to the emitter of the transistor Q3, the base of the transistor Q3 is connected to one end of the resistor R12, and the collector of the transistor Q3 is respectively connected to one end of the resistor R13 and the pin RX of the chip U1 in the millimeter-wave radar module. The model of the chip U1 is R60AFD1. The other end of the resistor R12 and the other end of the resistor R13 are both connected to the power supply;

[0038] Pin PA10 of the main control chip U2 is respectively connected to one end of the resistor R16 and the collector of the transistor Q4, the other end of the resistor R16 is connected to the power supply, the emitter of the transistor Q4 is grounded, the base of the transistor Q4 is connected to one end of the resistor R15, the other end of the resistor R15 is respectively connected to one end of the resistor R14 and the collector of the transistor Q5, the other end of the resistor R14 is connected to the power supply, the emitter of the transistor Q5 is grounded, the base of the transistor Q5 is connected to one end of the resistor R17, the other end of the resistor R17 is connected to the pin TX of the chip U1 in the millimeter wave radar module, the pin 1 of the chip U1 is respectively connected to the power supply and the grounding capacitor C34, and the pin 4 of the chip U1 is grounded.

[0039] like Figure 3 As shown, the main control chip U2 is connected to the wireless WIFI module through pin PA2 and pin PA3, the pin PA2 of the main control chip U2 is connected to one end of the resistor R25, and the other end of the resistor R25 is connected to the pin RXD of the chip U6. The chip U6 model is ESP-12F, the pin RST of the chip U6 is connected to one end of the resistor R18, the pin EN of the chip U6 is connected to one end of the resistor R19, and the other end of the resistor R18 and the other end of the resistor R19 are both connected to the power supply, the pin VCC of the chip U6 is respectively connected to the power supply and the grounding capacitor C12, the pin IO0 of the chip U6 is connected to one end of the resistor R20, and the other end of the resistor R20 is connected to the grounding resistor R23, the pin IO2 of the chip U6 is connected to one end of the resistor R22, and the other end of the resistor R22 is connected to the power supply, and the pin IO15 of the chip U6 is connected to the grounding resistor R21;

[0040] The pin PA3 of the main control chip U2 is connected to one end of the resistor R24, and the other end of the resistor R24 ​​is connected to the pin TXD of the chip U6.

[0041] Wireless WIFI module systems usually include the following key parts: power management, radio frequency (RF) circuit, antenna matching, digital interface and control circuit, etc.

[0042] Power input and voltage regulator circuit: WiFi modules typically require a stable voltage supply, typically 3.3V or 5V. The voltage regulator circuit is responsible for converting the input voltage (such as a battery or USB power source) into the stable voltage required by the WiFi module. Decoupling capacitors are placed near the power pins to filter out high-frequency noise on the power line and ensure proper operation of the WiFi module.

[0043] The radio frequency (RF) circuit is the core of the WiFi module, responsible for transmitting and receiving 2.4GHz or 5GHz RF signals. This module integrates a mixer, power amplifier, low-noise amplifier (LNA), filter, and RF switch. The frequency synthesizer and oscillator generate the required RF signal carrier. The frequency synthesizer uses phase-locked loop (PLL) technology to convert a reference clock signal (typically provided by a crystal oscillator) into the required high-frequency signal.

[0044] The antenna matching network is the part of the Wi-Fi module that communicates with the outside world, responsible for transmitting and receiving electromagnetic wave signals. A matching network (composed of inductors, capacitors, and resistors) is typically required between the antenna and the RF transceiver module to maximize power transmission efficiency and reduce reflections.

[0045] Digital interfaces include control and data interfaces and GPIO interfaces. Control and data interfaces: WiFi modules typically communicate with the host MCU through SPI, UART, I2C, or SDIO interfaces. These interfaces transmit control signals and data, such as commands, data packets, and status information. GPIO interfaces: General-purpose input and output (GPIO) pins on a module are used to connect to external devices or trigger interrupts.

[0046] The control circuit includes a microcontroller or processor. Some WiFi modules have a built-in microcontroller to manage the wireless protocol stack (such as TCP / IP, HTTP) and process wireless communication protocols.

[0047] The WiFi module circuit provides a stable operating voltage for the module through power management, the RF circuit handles the transmission and reception of wireless signals, the antenna matching network optimizes signal transmission, the digital interface realizes communication with the main control MCU, and the control circuit manages the operation of the entire WiFi communication protocol.

[0048] like Figure 4 As shown, the main control chip U2 is connected to the Bluetooth module through pins PB10 and PB11. The pin PB10 of the main control chip U2 is connected to one end of the resistor R27, and the other end of the resistor R27 is connected to the pin RXD of the chip U7. The model of the chip U7 is HC-08. The pin PB11 of the main control chip U2 is connected to one end of the resistor R26, and the other end of the resistor R26 is connected to the pin TXD of the chip U7. The pin GND of the chip U7 is grounded, and the pin 3V3 of the chip U7 is respectively connected to the grounding capacitor C35 and the power supply.

[0049] like Figure 5As shown, the pin PC13-TAMPER-RTC of the main control chip U2 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the cathode of the light-emitting diode LED2, the anode of the light-emitting diode LED2 is connected to the power supply, the power supply is also connected to the anode of the light-emitting diode LED1, and the cathode of the light-emitting diode LED1 is connected to the ground resistor R6;

[0050] The fall detection system further includes a crystal oscillator circuit, which includes a crystal oscillator X1, a capacitor C14, and a capacitor C16. The pin PD0-OSC_IN of the main control chip U2 is connected to the grounded capacitor C14 and one end of the crystal oscillator X1, respectively. The pin PD1-OSC_OUT of the main control chip U2 is connected to the grounded capacitor C16 and the other end of the crystal oscillator X1, respectively.

[0051] A crystal oscillator circuit provides a stable clock signal for a microcontroller or other digital circuit. A crystal oscillator (Crystal Oscillator) generates a precise frequency through its physical vibration properties.

[0052] Crystal oscillator selection: The frequency of the crystal oscillator is determined by the size and material of the crystal. In this system, the frequency is 8MHz. The microcontroller obtains the clock signal from an external crystal oscillator or an internal oscillator.

[0053] Oscillator Circuit: A typical crystal oscillator circuit consists of a parallel resonant crystal and two small capacitors forming a feedback loop. The capacitors help stabilize and tune the oscillator's frequency.

[0054] Load capacitance: The capacitance connected in parallel with the crystal is called load capacitance, which affects the operating frequency of the crystal. Correctly selecting the load capacitance ensures that the crystal oscillator operates at the desired frequency.

[0055] The fall detection system further includes a reset circuit, which includes a switch SW1, a capacitor C1, and a resistor R7. The pin NRST of the main control chip U2 is connected to one end of the resistor R7, the grounded capacitor C1, and the port 1 of the switch SW1, respectively. The other end of the resistor R7 is connected to the power supply, and the port 2 of the switch SW1 is grounded.

[0056] A reset circuit is used to restore a system to a known initial state and is typically triggered during power-up, power-down, or error conditions. The reset signal ensures that the microcontroller or processor starts operating from a stable state.

[0057] Power-on reset: When the circuit is powered on, the reset circuit generates a reset signal to ensure that the system remains in the reset state until the power supply voltage stabilizes. A common circuit is the RC reset circuit, which delays the release of the reset signal by using the charging characteristics of the capacitor.

[0058] Manual reset: Set a button that pulls the reset pin low when pressed, forcing the system to reset.

[0059] The fall detection system also includes a download circuit, which includes a connector P1, a resistor R1, a resistor R2, a resistor R3, and a resistor R4. The pin PA13 of the main control chip U2 is connected to one end of the resistor R2, and the other end of the resistor R2 is respectively connected to one end of the resistor R1 and port 2 of the connector P1. The model of the connector P1 is HEADER_1*4P. The other end of the resistor R1 is respectively connected to the power supply and port 1 of the connector P1. The port 3 of the connector P1 is respectively connected to one end of the grounding resistor R3 and the resistor R4. The other end of the resistor R4 is connected to the pin PA14 of the main control chip U2. Port 4 of the connector P1 is grounded.

[0060] The download circuit is used to download firmware or programs to the memory of the microcontroller, usually for development, debugging or updating the system.

[0061] The JTAG / SWD interface is a debugging and downloading interface that allows code to be downloaded to the MCU through dedicated hardware tools (such as ST-Link) and debugged in real time.

[0062] The fall detection system also includes a radar switch circuit, which includes a transistor Q1, a transistor Q2, a resistor R9, a resistor R10, a resistor R11, a capacitor C23, a capacitor C24 and a capacitor C25. The pin PB4 of the main control chip U2 is connected to one end of the resistor R10, and the other end of the resistor R10 is respectively connected to the ground resistor R11 and the base of the transistor Q2. The emitter of the transistor Q2 is grounded, and the collector of the transistor Q3 is respectively connected to the base of the transistor Q1 and one end of the resistor R9. The emitter of the transistor Q1 and the other end of the resistor R9 are both connected to a power supply. The collector of the transistor Q1 is respectively connected to the ground capacitor C23, the ground capacitor C24, the ground capacitor C25 and an external 5V power supply VCC_5V_R;

[0063] The radar switch circuit is connected to the GPIO pin. When the pin is pulled high, the radar module can work normally. When the pin is pulled low, the module stops working.

[0064] like Figure 6 As shown, the fall detection system further includes a BOOT circuit, the BOOT circuit includes a resistor R8, and the pin BOOT0 of the main control chip U2 is connected to the ground capacitor R8;

[0065] The BOOT circuit is used to select the microcontroller's boot mode. That is, after power-on or reset, it determines where the microcontroller loads the program (such as Flash, RAM, external memory, etc.). The level of the BOOT pin is read at power-on or reset to determine the microcontroller's boot mode. Different level combinations may correspond to different boot methods, such as booting from built-in Flash or booting from external memory.

[0066] Enter Bootloader mode (for downloading firmware);

[0067] Pull-up / pull-down resistor: The BOOT pin is usually connected to VCC or GND through a pull-up or pull-down resistor to ensure that the pin has a certain level when it is not connected and prevent it from floating.

[0068] The fall detection system further includes a power supply circuit, which includes an external power supply USB1, wherein a VCC pin of the external power supply USB1 is respectively connected to a power supply, a grounding capacitor C17, a grounding capacitor C10, a grounding capacitor C18, and a grounding capacitor C19, and a GND pin and an EP pin of the external power supply USB1 are both grounded;

[0069] The power supply circuit is responsible for providing stable voltage and current to all components in the system. A typical power supply circuit includes power input, voltage regulator, filter, protection circuit, etc.

[0070] Power supply circuits usually draw power from an external power source (such as a battery, adapter, or USB), and the input voltage may be higher or lower than the voltage required by the system.

[0071] Linear regulators are used to reduce high input voltages to stable output voltages. Their advantages are simple circuits and low output ripple. Their disadvantages are low efficiency and they are suitable for low-power applications.

[0072] A filter capacitor is added to the output end of the power supply to filter out power ripple and noise and ensure the stability of the output voltage.

[0073] The fall detection system also includes a step-down circuit, which includes a chip U4. The model of the chip U4 is SGM2036-3.3YN5G / TR. The IN pin of the chip U4 is respectively connected to its EN pin, the power supply and the ground capacitor C20. The GND pin of the chip U4 is grounded. The OUT pin of the chip U4 is respectively connected to the power supply and the ground capacitor C21. The BP / FP pin of the chip U4 is connected to the ground capacitor C22.

[0074] A step-down circuit is used to reduce a higher voltage to a specific lower voltage level. Common step-down circuits include voltage divider resistors, voltage regulators, and Zener diodes.

[0075] A linear voltage regulator directly steps down the input voltage to the desired output voltage, providing a stable output. It's suitable for applications where voltage differences are small and load currents are low. In this system, the 5V power supply can be stepped down to 3.3V via a voltage regulator to drive 3.3V logic circuits.

[0076] The fall detection system further includes an inductor L1, a grounding capacitor C26, a grounding capacitor C27, a grounding capacitor C28, a grounding capacitor C29, a grounding capacitor C30, a grounding capacitor C31, a grounding capacitor C32, and a grounding capacitor C33, both ends of the inductor L1 are connected to a power supply, and the grounding capacitors C26, C27, C28, C29, C30, C31, C32, and C33 are all connected to a power supply;

[0077] In this embodiment, power supply VCC_S and VCC3V3 are used for power isolation through an inductor L1. VCC_S is used to power the Bluetooth module and the wireless WIFI module separately to reduce mutual interference between the modules. When the inductor L1 is removed, the power supply of the Bluetooth module and the wireless WIFI module can be cut off.

[0078] The embedded microprocessor, Bluetooth module, millimeter-wave radar module and wireless WIFI module are integrated on a PCB board, which is placed inside a hardware circuit board housing. The hardware circuit board housing is made of LEDO 6060SLA photosensitive and resin materials, and the surface is polished. The size of the hardware circuit board housing is 0.5*5.48*6.43cm.

[0079] The Bluetooth module adopts a data transmission module based on the Bluetooth Specification V4.0 BLE Bluetooth protocol, and the wireless operating frequency band is 2.4GHz ISM.

[0080] The Bluetooth module uses GFSK (Gaussian Frequency Shift Keying) digital modulation technology, which uses a Gaussian filter to modulate the frequency. The module has a maximum transmit power of 4dBm and a receive sensitivity of -93dBm, enabling ultra-long-range communication of up to 80 meters in open air environments.

[0081] The wireless Wi-Fi module's core processor is the ESP8266. This module integrates the Tensilica L106 ultra-low-power 32-bit micro MCU in a compact package. The ESP8266 features a 16-bit Lite Mode, supports 80MHz and 160MHz clock speeds, supports an RTOS, and integrates the Wi-Fi MAC / BB / RF / PA / LNA. The module supports standard IEEE 802.11b / g / n protocols and a complete TCP / IP stack. This module can be used to add networking capabilities to existing devices or to build a standalone network controller.

[0082] In one embodiment of the present invention, first, the entire hardware system is reset and the clock source is turned on by the embedded microprocessor, and the universal asynchronous receiver-transmitter (UART) and the universal bus protocol I2C are set to communicate with the main control chip. A hardware reset line (RESET) is provided in the embedded system. When the line is pulled low, the entire system will be reset. The reset line can be pulled low for a period of time by the GPIO controller of the microprocessor and then released to reset the entire hardware system. After reset, the clock source of the system is turned on by configuring and enabling the internal RC oscillator through the clock control unit (RCC module) of the microprocessor to provide a clock signal to the microprocessor and other peripherals.

[0083] Next, initialize the serial port and enable serial port interrupts. This establishes connections between each module and the main control chip, allowing data received by the module to be directly transferred to the target device. DMA (Direct Memory Access) is used for data transfer. The DMA controller is an independent hardware module that directly accesses system memory and peripherals. When a peripheral requires data transfer, the DMA controller can replace the CPU to complete the data transfer. The DMA controller reads data from the peripheral and writes it directly to the memory, or reads data from the memory and writes it directly to the peripheral, completely eliminating CPU intervention. This allows data transfers to be completed without consuming CPU resources, significantly improving data transfer efficiency and speed by transmitting received data directly to the target device. Next, configure the UART controller, including parameters such as the baud rate, data bits, stop bits, and parity. Configure the GPIO pins for UART function and connect them to the UART peripheral. Configure the I2C controller's clock frequency, mode, address, and other parameters. Configure the GPIO pins for I2C function and connect them to the I2C peripheral. Enable the UART and I2C modules to establish communication between components such as the millimeter-wave radar and external sensors and the main control chip.

[0084] Radar is a self-contained air-sensing sensor. It is a module composed of a radio frequency antenna, a radar chip and a high-speed main frequency MCU. It relies on a stable, flexible and superior algorithm architecture core to solve the detection needs of various scenarios. It can be equipped with a host computer or host to flexibly output detection status and data.

[0085] Design schematics and PCB (Printed Circuit Board) to achieve lightweight hardware systems while improving overall system stability. Figure 7 and 8 As shown, the main control chip is located in the center of the PCB. The rectangular area on the right is the Bluetooth module. The six vias above the chip and the eight vias below it are radar pins, which are connected to the main control chip using a bottom-level direct-plug method. The Wi-Fi module is located on the left side of the radar in the bottom-level PCB schematic and is connected to the main control chip via bottom-level traces. The schematic design uses a 5V, 1A Type-C connector for power supply. The radar's rated supply voltage must be between 4.9V and 6V, and under normal operating conditions, the rated input current must be at least 200mA. The power supply ripple must be ≤100mV. The main control chip is the STM32F103C8T6, which operates at 3.3V. Therefore, an AMS1117 voltage regulator is used to ensure a 3.3V input voltage to the main control chip. The hardware system is divided into multiple functional modules, such as the power module, communication module, and sensor module, utilizing a modular design to reduce system complexity. Design the PCB layout according to the schematics, rationally arrange the placement and connection of components to minimize the PCB size. Ensure the proper layout of signal lines and add vias to reduce impedance interference. Connect the assembled hardware system to the appropriate power supply and peripherals, perform system debugging, and ensure the stability of the hardware system's functionality and performance. Draw the footprints of the millimeter-wave radar, wireless module, and various resistors and capacitors, and perform logical and electrical verification of the designed schematics to ensure the circuit meets design requirements.

[0086] The configuration environment used to develop the fall detection system is shown in Table 1.

[0087] Table 1 Environmental configuration table

[0088]

[0089] The hardware circuit board housing is fabricated to facilitate ceiling-mounted installation in indoor spaces and to define the device's detection area and mounting height. The radar transmits a 60GHz millimeter-wave signal, which is reflected by the target. The transmitted signal is demodulated and processed through amplification, filtering, and ADC processing to generate the demodulated echo signal. The MCU calculates the amplitude, frequency, and phase of the echo signal, ultimately enabling measurement of target parameters (such as falls, stationary dwell, motion, and micro-motion) and scenario assessment.

[0090] The radar antenna transmits electromagnetic wave signals and synchronously receives the echo signals reflected by the target. The radar processor analyzes the phase difference and energy changes between the waveform parameters of the echo signals from different receiving antennas, and feeds back information such as the target's distance, direction, speed, and motion energy, thereby detecting the posture of people.

[0091] like Figure 9 and Figure 10 As shown, the radar's mounting height must be at least 1mm higher than other components. The housing structure must maintain a 2-5mm gap between the radar antenna and the housing. The non-metallic detection surface must be flat to avoid curves that could affect performance across the entire scanning area. The radar covers a three-dimensional sector area with a horizontal angle of 100° and a vertical angle of 100°. The radar is mounted on the roof, illuminating vertically downward. The radar installation height is approximately 2.4 to 2.8 meters. The radar beam covers a circular area with a maximum radius of 1.5 meters for fall detection, 2 meters for human falls, and 2.5 meters for human motion detection.

[0092] In the client software, select the fall detection device via Bluetooth. When the WiFi connection interface pops up, select the correct WiFi network for the device, establish a connection between the device and the remote server, and then execute the fall detection function. The user navigates to the device's control interface or app, finds the human presence detection and human fall detection switches, and activates them using interactive buttons. The client sends the corresponding control commands to the device, instructing it to enable human presence detection and human fall detection. Upon receiving the client's control commands, the device initiates the corresponding detection tasks based on the commands. When the human presence detection task is activated, the device begins monitoring the surrounding environment, using its millimeter-wave radar sensor to detect the presence of a human within its monitoring range. When the human fall detection task is activated, the radar sensor detects falls within its monitoring range to determine whether a human fall has occurred. If a human presence is detected, the device can trigger a corresponding response action, such as sending an alert notification. If a human fall is detected, the device takes emergency measures, automatically calling emergency contacts and sending a distress message. The device also sends detection results back to the client, which can display relevant prompts or alerts to inform the user of the current detection status. Depending on the actual situation, the device can continue to perform continuous monitoring tasks, regularly send detection results to the client, or perform corresponding shutdown or adjustment operations according to the client's instructions.

[0093] The utility model adopts embedded, Internet of Things, integrated radar, wireless modules, etc. to detect human presence and falls. The non-contact detection method of millimeter wave radar greatly optimizes the detection difficulty and provides convenience for the use of the fall function. In order to view the detection results more intuitively and effectively, client application software is developed, and the software data is uploaded to the server using a wireless module. The detected data is updated in real time on the client. The camera is used to collect spandex yarn defect images or video data, and the collected data is pre-processed by parsing and format conversion. A cloud server is created, product functions are set, and the detection data of the device is received and sent to the client. This method enhances the stability of data transmission on the basis of wireless data transmission and optimizes the difficulty of users using the fall device. Modify the millimeter wave radar parameters and the detection judgment time to obtain the most effective fall detection method. Realize three-terminal real-time intercommunication of fall detection and human presence detection data.

[0094] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can, based on the technical teachings disclosed in this utility model, make various other specific variations and combinations that do not depart from the essence of the present utility model, and such variations and combinations are still within the scope of protection of the utility model.

Claims

1. A fall detection system based on an embedded microprocessor, characterized in that: It includes an embedded microprocessor, a Bluetooth module, a millimeter-wave radar module and a wireless WIFI module. The embedded microprocessor serves as the main control chip and is connected to the Bluetooth module, the millimeter-wave radar module and the wireless WIFI module respectively. The main control chip adopts the STM32F103C8T6 chip; The main control chip U2 is connected to the millimeter-wave radar module through pins PA9 and PA10. Pin PA9 of the main control chip U2 is connected to the emitter of the transistor Q3. The base of the transistor Q3 is connected to one end of the resistor R12. The collector of the transistor Q3 is respectively connected to one end of the resistor R13 and the pin RX of the chip U1 in the millimeter-wave radar module. The model of the chip U1 is R60AFD1. The other end of the resistor R12 and the other end of the resistor R13 are both connected to the power supply; Pin PA10 of the main control chip U2 is respectively connected to one end of the resistor R16 and the collector of the transistor Q4, the other end of the resistor R16 is connected to the power supply, the emitter of the transistor Q4 is grounded, the base of the transistor Q4 is connected to one end of the resistor R15, the other end of the resistor R15 is respectively connected to one end of the resistor R14 and the collector of the transistor Q5, the other end of the resistor R14 is connected to the power supply, the emitter of the transistor Q5 is grounded, the base of the transistor Q5 is connected to one end of the resistor R17, the other end of the resistor R17 is connected to the pin TX of the chip U1 in the millimeter wave radar module, the pin 1 of the chip U1 is respectively connected to the power supply and the grounding capacitor C34, and the pin 4 of the chip U1 is grounded.

2. The fall detection system based on embedded microprocessor according to claim 1, characterized in that: The main control chip U2 is connected to the wireless WIFI module through pins PA2 and PA3. The pin PA2 of the main control chip U2 is connected to one end of the resistor R25, and the other end of the resistor R25 is connected to the pin RXD of the chip U6. The chip U6 model is ESP-12F. The pin RST of the chip U6 is connected to one end of the resistor R18, and the pin EN of the chip U6 is connected to one end of the resistor R19. The other end of the resistor R18 and the other end of the resistor R19 are both connected to the power supply. The pin VCC of the chip U6 is respectively connected to the power supply and the grounding capacitor C12. The pin IO0 of the chip U6 is connected to one end of the resistor R20, and the other end of the resistor R20 is connected to the grounding resistor R23. The pin IO2 of the chip U6 is connected to one end of the resistor R22, and the other end of the resistor R22 is connected to the power supply. The pin IO15 of the chip U6 is connected to the grounding resistor R21; The pin PA3 of the main control chip U2 is connected to one end of the resistor R24, and the other end of the resistor R24 ​​is connected to the pin TXD of the chip U6.

3. The embedded microprocessor-based fall detection system according to claim 2, characterized in that: The main control chip U2 is connected to the Bluetooth module through pins PB10 and PB11. The pin PB10 of the main control chip U2 is connected to one end of the resistor R27, and the other end of the resistor R27 is connected to the pin RXD of the chip U7. The model of the chip U7 is HC-08. The pin PB11 of the main control chip U2 is connected to one end of the resistor R26, and the other end of the resistor R26 is connected to the pin TXD of the chip U7. The pin GND of the chip U7 is grounded, and the pin 3V3 of the chip U7 is respectively connected to the grounding capacitor C35 and the power supply.

4. The embedded microprocessor-based fall detection system according to claim 3, characterized in that: Pin PC13-TAMPER-RTC of the main control chip U2 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the cathode of the light-emitting diode LED2, the anode of the light-emitting diode LED2 is connected to the power supply, the power supply is also connected to the anode of the light-emitting diode LED1, and the cathode of the light-emitting diode LED1 is connected to the ground resistor R6; The fall detection system further includes a crystal oscillator circuit, which includes a crystal oscillator X1, a capacitor C14, and a capacitor C16. The pin PD0-OSC_IN of the main control chip U2 is connected to the grounded capacitor C14 and one end of the crystal oscillator X1, respectively. The pin PD1-OSC_OUT of the main control chip U2 is connected to the grounded capacitor C16 and the other end of the crystal oscillator X1, respectively. The fall detection system further includes a reset circuit, which includes a switch SW1, a capacitor C1, and a resistor R7. The pin NRST of the main control chip U2 is connected to one end of the resistor R7, the grounded capacitor C1, and the port 1 of the switch SW1, respectively. The other end of the resistor R7 is connected to the power supply, and the port 2 of the switch SW1 is grounded. The fall detection system also includes a download circuit, which includes a connector P1, a resistor R1, a resistor R2, a resistor R3, and a resistor R4. The pin PA13 of the main control chip U2 is connected to one end of the resistor R2, and the other end of the resistor R2 is respectively connected to one end of the resistor R1 and port 2 of the connector P1. The model of the connector P1 is HEADER_1*4P. The other end of the resistor R1 is respectively connected to the power supply and port 1 of the connector P1. The port 3 of the connector P1 is respectively connected to one end of the grounding resistor R3 and the resistor R4. The other end of the resistor R4 is connected to the pin PA14 of the main control chip U2. Port 4 of the connector P1 is grounded. The fall detection system also includes a radar switch circuit, which includes a transistor Q1, a transistor Q2, a resistor R9, a resistor R10, a resistor R11, a capacitor C23, a capacitor C24 and a capacitor C25. The pin PB4 of the main control chip U2 is connected to one end of the resistor R10, and the other end of the resistor R10 is respectively connected to the ground resistor R11 and the base of the transistor Q2. The emitter of the transistor Q2 is grounded, and the collector of the transistor Q3 is respectively connected to the base of the transistor Q1 and one end of the resistor R9. The emitter of the transistor Q1 and the other end of the resistor R9 are both connected to a power supply. The collector of the transistor Q1 is respectively connected to the ground capacitor C23, the ground capacitor C24, the ground capacitor C25 and an external 5V power supply VCC_5V_R; The fall detection system further includes a BOOT circuit, the BOOT circuit including a resistor R8, and the pin BOOT0 of the main control chip U2 is connected to the ground capacitor R8; The fall detection system further includes a power supply circuit, which includes an external power supply USB1, wherein a VCC pin of the external power supply USB1 is respectively connected to a power supply, a grounding capacitor C17, a grounding capacitor C10, a grounding capacitor C18, and a grounding capacitor C19, and a GND pin and an EP pin of the external power supply USB1 are both grounded; The fall detection system also includes a step-down circuit, which includes a chip U4. The model of the chip U4 is SGM2036-3.3YN5G / TR. The IN pin of the chip U4 is respectively connected to its EN pin, the power supply and the ground capacitor C20. The GND pin of the chip U4 is grounded. The OUT pin of the chip U4 is respectively connected to the power supply and the ground capacitor C21. The BP / FP pin of the chip U4 is connected to the ground capacitor C22. The fall detection system also includes an inductor L1, a grounding capacitor C26, a grounding capacitor C27, a grounding capacitor C28, a grounding capacitor C29, a grounding capacitor C30, a grounding capacitor C31, a grounding capacitor C32, and a grounding capacitor C33. Both ends of the inductor L1 are connected to a power supply, and the grounding capacitors C26, C27, C28, C29, C30, C31, C32, and C33 are all connected to a power supply.

5. The embedded microprocessor-based fall detection system according to claim 1, characterized in that: The embedded microprocessor, Bluetooth module, millimeter-wave radar module and wireless WIFI module are integrated on a PCB board, which is placed inside a hardware circuit board shell. The hardware circuit board shell is made of LEDO 6060 SLA photosensitive and resin materials, and the surface is polished. The size of the hardware circuit board shell is 0.5 * 5.48 * 6.43 cm.

6. The embedded microprocessor-based fall detection system according to claim 1, characterized in that: The Bluetooth module adopts a data transmission module based on the Bluetooth Specification V4.0 BLE Bluetooth protocol, and the wireless operating frequency band is 2.4GHz ISM.

7. The embedded microprocessor-based fall detection system according to claim 1, characterized in that: The core processor of the wireless WIFI module is ESP8266.

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