Intelligent data acquisition system based on SiC ultraviolet photoelectric detector

Abstract

The invention relates to the technical field of ultraviolet photoelectric detectors, and discloses an intelligent data acquisition system based on a SiC ultraviolet photoelectric detector, which comprises a Pico W main control unit, a low-noise power management module, a photoelectric acquisition front end, a sound-light alarm driving unit, a man-machine interaction display module and a dual-mode communication module. The Pico W main control unit coordinates data interaction of each module; the low-noise power supply management module avoids an onboard switching power supply loop through physical wiring and provides a physically isolated voltage-stabilized power supply for the photoelectric acquisition front end; the photoelectric acquisition front end constructs a transimpedance amplification framework to output analog voltage; the Net-WiFi communication module supports port multiplexing, and the Bluetooth communication module adopts a big data fragmentation mechanism. The problems that weak ultraviolet signals are easily interfered by power supply noise and transmission is discontinuous are solved, the signal-to-noise ratio is optimized through analog-to-digital power supply isolation, and high-precision real-time acquisition and monitoring of ultraviolet radiation are realized in combination with circulating storage and a high-efficiency communication protocol.

Description

Technical Field

[0001] This invention relates to the field of ultraviolet photodetector technology, specifically to an intelligent data acquisition system based on a SiC ultraviolet photodetector. Background Technology

[0002] Silicon carbide (SiC) ultraviolet photodetectors are used in environmental ultraviolet radiation monitoring, industrial ultraviolet light source detection, and flame detection due to the wide bandgap, high thermal conductivity, and strong radiation resistance of silicon carbide materials. The photocurrent signal generated by SiC ultraviolet photodetectors when receiving ultraviolet radiation is typically extremely weak, ranging from nanoamperes to picoamperes.

[0003] Existing ultraviolet (UV) monitoring equipment typically uses an embedded microcontroller that integrates digital logic processing and analog signal acquisition as its core control unit. To improve power conversion efficiency, embedded microcontrollers generally employ onboard switch-mode power converters to convert the input voltage to the core operating voltage. These switch-mode power converters generate high-frequency switching noise and power ripple during operation. In the design of miniaturized portable data acquisition terminals, the analog signal acquisition circuitry often shares the power ground loop and power supply network with the microcontroller's digital logic circuitry. The high-frequency switching noise generated by the switch-mode power converter can easily couple to high-gain transimpedance amplifier circuits through the power supply lines. Weak photocurrent signals are easily drowned out by power supply noise, leading to a decrease in the signal-to-noise ratio of the analog front-end output voltage, resulting in significant errors in the UV radiation intensity measurement results.

[0004] In terms of data transmission and interaction, existing ultraviolet monitoring equipment typically employs a single wireless communication method. Relying solely on wireless LAN communication limits the monitoring equipment to operating within network coverage areas with fixed wireless access points, making it unsuitable for mobile monitoring or remote, network-free environments. While relying solely on Bluetooth Low Energy (BLE) communication achieves point-to-point connections, the BLE protocol imposes strict limitations on the maximum transmission unit (MTU) of data packets at the link layer. When the monitoring equipment needs to transmit long data packets containing multi-dimensional sensor data, status information, and timestamps, the packet length often exceeds the default MTU value for BLE connections. Directly sending long data packets results in data truncation or loss at the link layer, preventing the receiving end from parsing complete monitoring data frames.

[0005] In terms of data storage and system reliability, the Flash storage resources integrated within embedded microcontrollers are extremely limited. Traditional data recording methods typically employ a linear append-only write mode. As the amount of monitoring data accumulates with increasing runtime, Flash storage space is quickly exhausted, preventing newly generated monitoring data from being written. Furthermore, in unattended environments such as outdoor or industrial sites, electromagnetic interference or network fluctuations can cause embedded software to stagnate or network connections to be interrupted. Monitoring devices lacking local circular storage management mechanisms, offline automatic operation logic, and hardware watchdog reset mechanisms will experience data recording interruptions when encountering network failures or program deadlocks. They must wait for manual on-site maintenance to resume normal operation, failing to meet the needs of long-term continuous monitoring.

[0006] Therefore, this invention proposes an intelligent data acquisition system based on SiC ultraviolet photodetectors to address the shortcomings of existing technologies. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an intelligent data acquisition system based on a SiC ultraviolet photodetector, which solves the problem of low acquisition accuracy of weak ultraviolet signals caused by high-frequency noise interference from the analog front end generated by the onboard switch-mode power converter of the microcontroller in existing embedded monitoring equipment.

[0008] To achieve the above objectives, the present invention provides the following technical solution: This invention provides an intelligent data acquisition system based on a SiC ultraviolet photodetector, including a Pico W main control unit, a low-noise power management module, a photoelectric acquisition front end, an audible and visual alarm drive unit, a human-machine interaction display module, a Net-WiFi communication module, a Bluetooth communication module, and a host monitoring system.

[0009] The Pico W main control unit uses the RP2040 microcontroller chip. The Pico W main control unit is responsible for coordinating the data interaction and logic control between the low-noise power management module, photoelectric acquisition front end, sound and light alarm drive unit and human-machine interaction display module.

[0010] The low-noise power management module (LMU) is responsible for performing high-purity power conversion. It converts the input DC power into regulated DC and outputs the regulated DC to the photoelectric acquisition front-end. To eliminate switching noise interference, the LMU physically bypasses the power supply circuit of the onboard switching power supply of the Pico W main control unit, thus achieving physical isolation between the analog and digital circuit power supplies. The LMU integrates a low-dropout linear regulator chip, input filter capacitors, and output voltage regulator capacitors. The output voltage of the LMU bypasses the internal switching-mode power converter of the Pico W main control unit, directly powering the photoelectric acquisition front-end through the printed circuit board traces, ensuring that the photoelectric acquisition front-end receives a clean power excitation.

[0011] The photoelectric acquisition front end is responsible for extracting and amplifying weak photocurrent signals. It employs a transimpedance amplifier circuit architecture and includes a photodiode, operational amplifier, and feedback resistor. To optimize the signal-to-noise ratio and ensure linearity, the front end does not include a voltage divider resistor connected in parallel in the feedback loop; the feedback loop consists only of the feedback resistor. The photodiode operates in photoconductive mode under the reverse voltage provided by the low-noise power management module. The analog voltage output by the front end is strictly equal to the product of the instantaneous photocurrent generated by the photodiode and the resistance of the feedback resistor. The Pico W main control unit reads the analog voltage value to quantify the ultraviolet radiation intensity.

[0012] The audible and visual alarm drive unit is responsible for performing safety warning tasks. It includes a buzzer, an LED, and a transistor drive circuit. To prevent circuit operation from impacting the power supply system, the filter capacitor connected in parallel across the buzzer and LED has been removed, eliminating the capacitor discharge surge current generated when the electronic switching element is turned on, thus protecting the output stability of the low-noise power management module.

[0013] The Net-WiFi communication module is responsible for establishing remote data transmission links based on the Transmission Control Protocol (TCP). The Net-WiFi communication module enables port multiplexing and sets the SO_REUSEADDR option of the network socket object to the enabled state. The SO_REUSEADDR option allows the Net-WiFi communication module to immediately rebind the network port after the Pico W master unit performs a soft reboot without waiting for the operating system to release port resources. The Net-WiFi communication module sets the maximum length parameter of the pending connection queue to 1 to ensure efficient processing of connection requests.

[0014] The Bluetooth communication module is responsible for establishing the near-field data transmission link and employs an application-layer large data fragmentation transmission mechanism. When the total byte length of the data packet to be transmitted exceeds the payload length allowed by the maximum transmission unit (MTU) value, the Bluetooth communication module determines the required total number of fragments by calculating the ratio of the total byte length of the data packet to the MTU value of the Bluetooth connection and rounding the result up. Based on the total number of fragments, the Bluetooth communication module divides the data packet to be transmitted into multiple sub-segments. At the beginning of each sub-segment, the Bluetooth communication module inserts a custom protocol header containing the current fragment sequence number and the total number of fragments to ensure that the receiving end can correctly reassemble the data.

[0015] The Pico W main control unit operates a circular overlay storage management mechanism to manage onboard storage space. When the Pico W main control unit generates a new monitoring data record, the circular overlay storage management mechanism reads all historical data lines stored in the target log file and calculates the total number of historical data lines. When the total number of lines is greater than or equal to a preset maximum record threshold, the circular overlay storage management mechanism determines the starting index position of the truncation operation based on a preset retention quantity parameter, and extracts data lines from the starting index position to the end of the historical data line list to form a retention data list. The new monitoring data record is appended to the end of the retention data list, thereby achieving automatic rotation storage of data.

[0016] The Pico W main control unit uses a JavaScript object-based simplified structure to encapsulate communication protocol data frames. These data frames include fields for UV level, UV index, light intensity, and CPU temperature. The Pico W main control unit performs safety alarm logic based on the real-time UV index. When the real-time UV index value is greater than or equal to the preset UV radiation safety threshold, the Pico W main control unit controls the audible and visual alarm drive unit to issue an audible and visual alarm signal.

[0017] This invention provides an intelligent data acquisition system based on a SiC ultraviolet photodetector. It has the following advantages: 1. This invention constructs an analog power supply circuit independent of the digital logic power supply circuit of the Pico W main control unit through a low-noise power management module. It utilizes the linear adjustment characteristics of the low-dropout linear regulator chip to isolate the high-frequency switching noise generated by the internal switch-mode power converter of the Pico W main control unit. Combined with the photoelectric acquisition front end that removes the voltage divider resistor element, it ensures that the weak photocurrent generated by the photodiode is amplified with high linearity under a pure DC voltage environment, thereby improving the signal-to-noise ratio and measurement accuracy of ultraviolet radiation intensity detection.

[0018] 2. This invention constructs a dual-mode heterogeneous communication mechanism through a Net-WiFi communication module and a Bluetooth communication module, allowing the intelligent data acquisition system to transmit data simultaneously through a remote wireless LAN link and a near-field low-power Bluetooth link. Furthermore, the Bluetooth communication module executes an application-layer big data segmentation transmission mechanism, using a custom protocol header containing the segmentation sequence number and the total number of segments to cut long data packets into sub-data segments that adapt to the maximum transmission unit limit. This solves the packet loss and truncation problem of the low-power Bluetooth protocol when transmitting large amounts of data, and realizes the complete concurrent distribution of multi-dimensional monitoring data in complex network environments.

[0019] 3. This invention utilizes a cyclic overlay storage management mechanism and an offline operation process for exception handling to work together. When the data volume of the Flash storage file system reaches a preset threshold, it automatically performs a first-in-first-out truncation operation using a sliding window strategy to release storage space. When an external network connection cannot be established, it automatically switches to offline operation mode. It outputs real-time data through a local human-computer interaction display module and uses an independent watchdog timer to monitor the software's operating status. This ensures that the intelligent data acquisition system can record historical ultraviolet radiation dose data continuously and stably for a long time in unattended, network-free outdoor environments with limited storage resources. Attached Figure Description

[0020] Figure 1 This is a system block diagram of the present invention; Figure 2 This is a schematic diagram of the photoelectric acquisition front-end circuit in this invention; Figure 3 This is a circuit schematic of the low-noise power management module in this invention; Figure 4 This is a schematic diagram of the sound and light alarm driving unit circuit in this invention; Figure 5 This is a flowchart of the Net-WiFi communication module in this invention; Figure 6 This is a flowchart of the circular storage management process in this invention; Figure 7 This is a flowchart of the Bluetooth fragmentation transmission process in this invention.

[0021] Legend 1. Pico W main control unit; 2. Low-noise power management module; 3. Photoelectric acquisition front end; 4. Audible and visual alarm drive unit; 5. Human-machine interaction display module; 6. Net-WiFi communication module; 7. Bluetooth communication module; 8. Upper-level monitoring system. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] See attached document Figure 1 This invention provides an intelligent data acquisition system based on a SiC ultraviolet photodetector, comprising a Pico W main control unit 1, a low-noise power management module 2, a photoelectric acquisition front end 3, an audible and visual alarm drive unit 4, a human-machine interaction display module 5, a Net-WiFi communication module 6, and a Bluetooth communication module 7.

[0024] The Pico W main control unit 1 uses the RP2040 microcontroller chip. It features a dual-core processor architecture, responsible for executing signal acquisition commands, running the network communication protocol stack, and handling logic control tasks. The Pico W main control unit 1 establishes electrical connections with various peripheral functional modules through general-purpose input / output interfaces, analog-to-digital conversion interfaces, and an internal communication bus. The low-noise power management module 2 uses an independent low-dropout linear regulator as its core power supply component. The low-noise power management module 2 disables the onboard switching power supply circuit of the Pico W main control unit 1 through circuit design, or avoids the onboard switching power supply circuit through physical routing. The low-noise power management module 2 converts the input DC power supply into clean, regulated DC power and outputs the regulated DC power to the photoelectric acquisition front-end 3. The low-noise power management module 2 achieves physical isolation between the analog circuit power supply and the digital circuit power supply, reducing the interference of power ripple on weak analog signals.

[0025] See attached document Figure 1 and attached Figure 2 The photoelectric acquisition front-end 3 is constructed using a transimpedance amplifier circuit architecture based on an operational amplifier. The photoelectric acquisition front-end 3 includes a photodiode, an operational amplifier, and a feedback resistor. The photodiode is in a reverse bias state. The anode of the photodiode is connected to the inverting input of the operational amplifier. The cathode of the photodiode is connected to a high-level reference voltage or grounded through a capacitor to filter out high-frequency noise. The non-inverting input of the operational amplifier is directly connected to analog ground. The feedback resistor is connected between the inverting input and the output of the operational amplifier. The photoelectric acquisition front-end 3 does not include a voltage divider resistor connected in parallel in the feedback loop to ensure a strictly linear relationship between the photocurrent and the output voltage. The output of the operational amplifier is connected to the analog-to-digital conversion pin of the Pico W main control unit 1, transmitting the amplified analog voltage signal to the Pico W main control unit 1.

[0026] The audible and visual alarm drive unit 4 includes a buzzer, an LED, and a transistor drive circuit. The transistor drive circuit uses a transistor or a metal-oxide-semiconductor field-effect transistor as the switching drive element. The base or gate of the transistor is connected to the general-purpose input / output pin of the Pico W main control unit 1. The collector or drain of the transistor is connected to the buzzer and the LED load. The audible and visual alarm drive unit 4 removes the capacitor connected in parallel across the load to prevent the surge current generated during switching from damaging the transistor drive circuit.

[0027] The human-machine interface display module 5 uses an organic light-emitting diode (OLED) display screen. The OLED display screen is connected to the Pico W main control unit 1 via an I2C communication bus. The human-machine interface display module 5 displays real-time UV levels, the internal temperature of the Pico W main control unit 1, network connection status, dynamic IP address, and system uptime. The Net-WiFi communication module 6 is based on the RF core integrated into the Pico W main control unit 1. The Net-WiFi communication module 6 is configured to establish a transmission control protocol server and enable port multiplexing. The Net-WiFi communication module 6 is used to establish a remote data transmission link with the host computer via a wireless network in environments with wireless LAN coverage.

[0028] The Bluetooth communication module 7 is implemented based on the RF core integrated in the Pico W main control unit 1. Bluetooth communication module 7 runs the Bluetooth Low Energy protocol stack. Bluetooth communication module 7 is configured to support application-layer big data fragmentation transmission mechanisms. Bluetooth communication module 7 is used to establish near-field data transmission links with mobile devices or host computers via Bluetooth point-to-point connections in environments without Wi-Fi coverage. Net-WiFi communication module 6 and Bluetooth communication module 7 support concurrent operation, allowing the dual-mode communication ultraviolet precision monitoring system based on an embedded microcontroller to simultaneously transmit monitoring data through two heterogeneous communication links.

[0029] See attached document Figure 1 and attached Figure 3 The low-noise power management module 2 includes a low-dropout linear regulator chip, an input filter capacitor, and an output regulating capacitor. The low-noise power management module 2 provides a highly stable and low-ripple analog power supply for the photoelectric acquisition front-end 3.

[0030] The voltage input pin of the low-dropout linear regulator chip is connected to the system's DC power input. The voltage input pin receives the raw DC input voltage. The ground pin is connected to the analog ground network. The enable pin is connected to the ON level, keeping the chip continuously ON. An input filter capacitor is connected between the voltage input pin and the analog ground network. This capacitor filters out conducted electromagnetic interference present in the raw DC input voltage. An output regulator capacitor is connected between the voltage output pin and the analog ground network. This capacitor reduces output voltage ripple and improves transient response characteristics.

[0031] The voltage output pin of the low-dropout linear regulator chip is directly connected to the power port of the photoelectric acquisition front-end 3 via printed circuit board traces. The low-noise power management module 2 constructs an analog power supply circuit independent of the digital logic power supply circuit of the Pico W main control unit 1. The Pico W main control unit 1 integrates a switch-mode power converter. The output voltage of the low-noise power management module 2 does not pass through the switch-mode power converter inside the Pico W main control unit 1. The low-noise power management module 2 utilizes the linear regulation characteristics of the low-dropout linear regulator chip to isolate the high-frequency switching noise generated by the switch-mode power converter. The low-noise power management module 2 ensures that the photoelectric acquisition front-end 3 operates in a clean DC voltage environment, preventing power supply noise from drowning out the weak ultraviolet photocurrent signal.

[0032] See attached document Figure 2 The photoelectric acquisition front-end 3 includes an operational amplifier, a photodiode, and a feedback resistor. The photoelectric acquisition front-end 3 converts the photocurrent signal generated by the photodiode sensing ultraviolet light into a voltage signal. The photodiode is reverse-biased. The cathode of the photodiode is connected to the regulated positive power supply output of the low-noise power management module 2. The anode of the photodiode is connected to the inverting input of the operational amplifier. The photodiode operates in photoconductive mode under reverse voltage. The photodiode generates a photocurrent when it receives ultraviolet radiation. The magnitude of the photocurrent is proportional to the intensity of the incident ultraviolet light. The non-inverting input of the operational amplifier is directly connected to analog ground. The potential at the non-inverting input of the operational amplifier is clamped at zero potential. Due to the virtual short characteristic of the operational amplifier, the potential at the inverting input of the operational amplifier remains at the virtual ground potential.

[0033] A feedback resistor is connected between the inverting input and output of the operational amplifier. The feedback resistor forms a deep voltage parallel negative feedback loop. The photoelectric acquisition front-end 3 does not contain any voltage divider resistors connected in series or parallel with the feedback resistor. The feedback loop consists solely of the feedback resistor, ensuring that the input photocurrent flows entirely through it. The signal conversion of the photoelectric acquisition front-end 3 follows Ohm's law. The output voltage of the operational amplifier is calculated using the following formula: ; In the formula, This represents the analog voltage value at the output of the operational amplifier; This indicates the instantaneous photocurrent value generated by the photodiode; This indicates the resistance value of the feedback resistor.

[0034] The output of the operational amplifier is connected to the analog-to-digital converter interface of the Pico W main control unit 1. The Pico W main control unit 1 acquires the analog voltage value output by the operational amplifier. The photoelectric acquisition front-end 3 utilizes the transimpedance amplification principle to achieve a linear conversion between weak current signals and voltage signals. This linear conversion characteristic ensures the accuracy of ultraviolet intensity measurement.

[0035] See attached document Figure 1 The Pico W main control unit 1 is built on the RP2040 microcontroller chip. The Pico W main control unit 1 is equipped with a general-purpose input / output interface, an analog-to-digital converter interface, and an internal communication bus interface. The analog-to-digital converter pin of the Pico W main control unit 1 is connected to the operational amplifier output of the photoelectric acquisition front-end 3. The Pico W main control unit 1 acquires the amplified ultraviolet photocurrent analog voltage signal through the analog-to-digital converter pin. The internal integrated circuit bus interface pin of the Pico W main control unit 1 is connected to the human-machine interface display module 5. The 3V3_EN enable pin of the Pico W main control unit 1 is connected to ground. Pulling the 3V3_EN enable pin low to ground causes the onboard switch-mode power converter of the Pico W main control unit 1 to be in the off state. The 3V3_OUT pin of the Pico W main control unit 1 serves as the power input interface connected to an external regulated power supply. The external regulated power supply directly provides the operating voltage to the RP2040 microcontroller chip through the 3V3_OUT pin.

[0036] See attached document Figure 1 and attached Figure 4The audible and visual alarm drive unit 4 includes a buzzer, a light-emitting diode (LED), and a transistor drive circuit. The transistor drive circuit is located between the Pico W main control unit 1 and the alarm load. The transistor drive circuit uses an NPN transistor or an N-channel enhancement-mode metal-oxide-semiconductor field-effect transistor (MOSFET) as the electronic switching element. The control electrode of the electronic switching element, i.e., the base of the transistor or the gate of the MOSFET, is connected to the general-purpose input / output pin of the Pico W main control unit 1 through a current-limiting resistor. The input electrode of the electronic switching element, i.e., the collector of the transistor or the drain of the MOSFET, is connected to the negative terminal of the buzzer and the cathode of the LED. The positive terminal of the buzzer and the anode of the LED are connected to the positive terminal of the system power supply. The output electrode of the electronic switching element, i.e., the emitter of the transistor or the source of the MOSFET, is connected to the digital ground network.

[0037] The Pico W main control unit 1 controls the electronic switching element to switch between on and off states by outputting a high-level or low-level control signal to the control electrode of the electronic switching element. When the electronic switching element is in the on state, the buzzer sounds an alarm and the LED flashes an alarm light. The filter capacitors connected in parallel across the buzzer and LED have been removed from the circuit topology of the audible and visual alarm drive unit 4. Removing the filter capacitors eliminates the capacitor discharge surge current generated when the electronic switching element is turned on. Eliminating the capacitor discharge surge current prevents damage to the electronic switching element inside the transistor drive circuit due to overcurrent. The audible and visual alarm drive unit 4 provides electrical isolation and amplification of the drive capability between the low-current general-purpose input / output pins of the Pico W main control unit 1 and the high-current alarm load.

[0038] See attached document Figure 1 Appendix Figure 5 Appendix Figure 6 and attached Figure 7 This invention provides a specific implementation of a dual-mode heterogeneous communication mechanism. The dual-mode heterogeneous communication mechanism includes a process where the Net-WiFi communication module 6 establishes a transmission control protocol server and a process where the Bluetooth communication module 7 performs application-layer big data fragmentation transmission. The Net-WiFi communication module 6 first initializes a network socket object in the Pico W host unit 1. The Net-WiFi communication module 6 configures the socket options of the network socket object. The Net-WiFi communication module 6 sets the SO_REUSEADDR option of the network socket object to the enabled state. The SO_REUSEADDR option allows the Net-WiFi communication module 6 to immediately rebind the network port after the Pico W host unit 1 performs a soft reboot. Enabling the SO_REUSEADDR option prevents the "address already in use" error caused by the operating system kernel keeping the port in the TIME_WAIT state.

[0039] Net-WiFi communication module 6 binds the network socket object to the local Internet Protocol (IP) address and a preset port number. Net-WiFi communication module 6 calls the listener function to put the network socket object into a passive listening state. When calling the listener function, Net-WiFi communication module 6 sets the maximum length parameter of the pending connection queue to 1. Setting the maximum length parameter of the pending connection queue to 1 forces the Transmission Control Protocol (TCP) server to process only one client connection request at a time. Limiting the number of concurrent connections to 1 reduces the random access memory usage of the Pico W main control unit 1 when maintaining network connectivity. Net-WiFi communication module 6 enters a blocking wait loop to accept connection requests from the host computer.

[0040] Bluetooth communication module 7 operates based on the Bluetooth Low Energy protocol stack. When sending long data packets, Bluetooth communication module 7 executes application-layer fragmentation logic. Bluetooth communication module 7 reads the total byte length of the data packet to be sent. Bluetooth communication module 7 obtains the maximum transmission unit (MTB) value determined by the current Bluetooth connection negotiation. When the total byte length of the data packet to be sent exceeds the payload length allowed by the MTB value, Bluetooth communication module 7 initiates the fragmentation transmission procedure. Bluetooth communication module 7 calculates the required total number of fragments. The total number of fragments is calculated using the following formula: ; In the formula, Indicates the total number of fragments required; Indicates the total length of the data packet to be sent in bytes; This indicates the maximum transmission unit value for a Bluetooth connection. Indicates the byte length of the custom protocol header; This indicates the rounding up operation.

[0041] The Bluetooth communication module 7 divides the data packet to be transmitted into multiple sub-segments based on the total number of fragments. The Bluetooth communication module 7 inserts a custom protocol header at the beginning of each sub-segment. The custom protocol header contains the current fragment sequence number and the total number of fragments. The custom protocol header is encoded in the format of "sequence number / total number". The custom protocol header is used by the receiving device to perform out-of-order reordering and integrity verification on the received sub-segments.

[0042] Bluetooth communication module 7 sequentially sends sub-data segments with custom protocol headers through the general attribute configuration file channel. After sending each sub-data segment, Bluetooth communication module 7 performs a first delay operation. The first delay operation lasts for a first preset duration. This first delay operation is used to release the occupied RF transmission buffer. When Bluetooth communication module 7 detects a transmission failure or congestion event, it performs a second delay operation. The second delay operation lasts for a second preset duration. The value of the second preset duration is greater than the value of the first preset duration. This second delay operation is used to wait for the wireless channel congestion to clear. Net-WiFi communication module 6 and Bluetooth communication module 7 run concurrently in different threads of the Pico W main control unit 1, achieving independent data transmission across dual links.

[0043] See attached document Figure 6 This invention provides a specific implementation of a circular overlay storage management mechanism. The circular overlay storage management mechanism operates on the Pico W main control unit 1. This mechanism manages read and write operations of the Flash storage file system, preventing long-term data recording from causing storage space overflow.

[0044] The circular overlay storage management mechanism employs a sliding window storage strategy. When the Pico W main control unit 1 collects and generates a new monitoring data record, the circular overlay storage management mechanism triggers a write check process. The mechanism opens the target log file located in the Flash storage file system in read mode. It reads all historical data lines stored in the target log file into the random access memory of the Pico W main control unit 1. The mechanism calculates the total number of current historical data lines. It then obtains a preset maximum record threshold. This preset maximum record threshold defines the upper limit of the number of data lines allowed to be stored in the target log file. Finally, the mechanism compares the total number of lines with the preset maximum record threshold.

[0045] When the total number of rows is greater than or equal to the preset maximum record threshold, the circular overlay storage management mechanism performs a first-in, first-out (FIFO) truncation operation. The circular overlay storage management mechanism determines the truncation point based on a preset retention parameter. The FIFO truncation operation aims to retain the data records with the most recent timestamps and remove the data records with the earliest timestamps. The circular overlay storage management mechanism calculates the starting index position for the truncation operation using the following formula: ; In the formula, This indicates the starting index value for extracting data from the list of read historical data rows; This indicates the total number of historical data rows currently read; This indicates the preset number of records to retain, and the preset number of records to retain is less than the preset maximum record threshold.

[0046] The circular overwrite storage management mechanism extracts all data rows from the starting index value to the end of the historical data row list, forming a retained data list. New monitoring data records are appended to the end of the retained data list. When the total number of rows is less than the preset maximum record threshold, the circular overwrite storage management mechanism directly appends new monitoring data records to the end of the read historical data row list. The circular overwrite storage management mechanism reopens the target log file in overwrite mode. The circular overwrite storage management mechanism writes the processed data list to the target log file. Overwrite mode clears the original data content in the target log file. Through periodic read, truncation, and rewrite operations, the circular overwrite storage management mechanism ensures that the Flash storage space occupied by the target log file is always maintained within a preset range, achieving continuous recording for an unlimited duration under limited storage resources.

[0047] The human-computer interaction and display refresh logic is executed by the Pico W main control unit 1. This logic is used to present the system status and monitoring data in real time on the human-computer interaction display module 5. The Pico W main control unit 1 initiates a timed refresh task. This task is triggered by a timer interrupt or the main loop scheduling mechanism. The Pico W main control unit 1 first performs a video memory clearing operation. This operation clears residual pixel data from the previous frame. This clearing operation prevents ghosting of the displayed content.

[0048] Pico W main control unit 1 performs multi-dimensional data acquisition steps. Pico W main control unit 1 reads the ultraviolet level value from the photoelectric acquisition front end 3. Pico W main control unit 1 reads the value from the temperature sensor integrated within Pico W main control unit 1. Pico W main control unit 1 queries the connection status flag of Net-WiFi communication module 6. When Net-WiFi communication module 6 is connected to the wireless LAN, Pico W main control unit 1 obtains the Internet Protocol address assigned to it via Dynamic Host Configuration Protocol (DHCP). Pico W main control unit 1 queries the broadcast status or connection status of Bluetooth communication module 7. Pico W main control unit 1 reads the number of currently stored data points recorded by the cyclic overlay storage management mechanism. Pico W main control unit 1 performs runtime calculation steps. Pico W main control unit 1 calculates the system runtime using the following formula: ; In the formula, This indicates the cumulative running time of the system since its last startup; This indicates the current system clock timestamp of Pico W main control unit 1; This indicates the startup timestamp when Pico W main control unit 1 completes the initialization sequence.

[0049] The Pico W main control unit 1 executes the display frame construction step. The Pico W main control unit 1 maps the collected multidimensional data to the pixel coordinate system of the human-machine interface display module 5. The display frame construction step adopts a layered layout strategy. The Pico W main control unit 1 renders the ultraviolet radiation level value to the first display line of the human-machine interface display module 5. The first display line serves as the core data monitoring area. The Pico W main control unit 1 renders the internal temperature sensor value to the second display line of the human-machine interface display module 5. The second display line serves as the equipment health diagnosis area. The internal temperature sensor value is used to indicate the thermal status of the equipment.

[0050] The Pico W main control unit 1 renders the connection status and Internet Protocol (IP) address of the Net-WiFi communication module 6 onto the third and fourth display lines of the human-machine interface display module 5. These third and fourth display lines serve as the network status and addressing information area. The Pico W main control unit 1 directly displays the dynamically acquired IP address. Directly displaying the IP address allows users to determine the device's network location without the assistance of host computer software. The Pico W main control unit 1 renders the status of the Bluetooth communication module 7, the number of stored data points, and the formatted system runtime onto the fifth and sixth display lines of the human-machine interface display module 5. These fifth and sixth display lines serve as the system status and log monitoring area.

[0051] Pico W main control unit 1 executes the hardware refresh procedure. Pico W main control unit 1 sends the completed display frame data to the display driver chip of the human-machine interaction display module 5 via its internal integrated circuit bus interface. The human-machine interaction display module 5 then updates the screen display content. The human-machine interaction and display refresh logic enables local visualization of multi-dimensional monitoring data.

[0052] This invention provides a specific implementation of the communication protocol data frame definition. The communication protocol data frame definition specifies the data exchange format between the Pico W main control unit 1 and the upper-level monitoring system 8. The data exchange format adopts a JavaScript object simplified spectrum structure. The JavaScript object simplified spectrum structure encapsulates real-time monitoring data into key-value pairs. The communication protocol data frame includes an ultraviolet (UV) level field, a UV index field, a light intensity field, and a central processing unit (CPU) temperature field. The UV level field uses the string "uv_level" as the key identifier. The UV level field stores an integer data type. The UV level field represents the risk level of the current UV radiation intensity. The UV index field uses the string "uvi" as the key identifier. The UV index field stores a floating-point data type. The UV index field represents the standard UV index value calculated based on the output voltage of the photoelectric acquisition front-end 3.

[0053] The UV index is calculated using the following formula: ; In the formula, This indicates the value of the UV index field; This represents the analog voltage value output by the photoelectric acquisition front-end 3; This represents the proportional conversion factor calibrated for the specific spectral response characteristics of a photodiode. This represents the zero-point drift compensation value.

[0054] The Illumination Intensity field uses the string "light" as the key identifier. It stores a floating-point data type. The Illumination Intensity field represents the raw analog voltage value acquired by the Pico W main control unit 1. It reflects the total radiant energy intensity of ambient light. The CPU Temperature field uses the string "cpu_temp" as the key identifier. It stores a floating-point data type. The CPU Temperature field represents the chip junction temperature value read from the internal temperature sensor of the RP2040 microcontroller. The CPU Temperature field is used by the host monitoring system 8 to assess the thermal health status of the Pico W main control unit 1.

[0055] The Pico W main control unit 1 serializes the UV level, UV index, light intensity, and CPU temperature fields into a standard JavaScript object musical notation string. The Pico W main control unit 1 sends this string to the host monitoring system 8 via either the Net-WiFi communication module 6 or the Bluetooth communication module 7. The host monitoring system 8 parses the string to update the real-time display interface. The host monitoring system 8 runs on a general-purpose computing device. The host monitoring system 8 constructs a graphical user interface (GUI). The GUI is visually divided into a communication configuration area at the top and a data visualization area in the lower middle section.

[0056] The communication configuration area includes a Wi-Fi configuration sub-area and a Bluetooth configuration sub-area. These sub-areas are arranged side-by-side horizontally. Logically, they are independent of each other. The Wi-Fi configuration sub-area includes an Internet Protocol (IP) address input box, a port number input box, and a network connection control button. The IP address input box receives the IP address string entered by the operator. This IP address string corresponds to the dynamically acquired address displayed on the human-machine interface display module 5 by the Pico W main control unit 1. The port number input box receives the port value being listened to by the transmission control protocol server. The network connection control button is used to trigger or disconnect the transmission control protocol connection with the Pico W main control unit 1.

[0057] The Bluetooth configuration sub-area includes a device scan control button and a Bluetooth connection control button. The device scan control button triggers the host monitoring system 8 to search for nearby low-power Bluetooth broadcast signals. The Bluetooth connection control button triggers the host monitoring system 8 to establish a universal attribute profile connection link with the selected Pico W master control unit 1. The host monitoring system 8 includes network connection status indicators and Bluetooth connection status indicators in the communication configuration area. The host monitoring system 8 monitors the status of the underlying network sockets and the Bluetooth adapter in real time. The host monitoring system 8 changes the background color and text content of the network connection status indicator and the Bluetooth connection status indicator according to the monitored status.

[0058] The host monitoring system 8 executes dual-mode concurrent interaction logic. It handles Wi-Fi and Bluetooth communication tasks in different execution threads. The host monitoring system 8 allows both the Transmission Control Protocol (TCP) connection link and the Bluetooth Low Energy (BLE) connection link to be active simultaneously. The host monitoring system 8 can simultaneously receive real-time monitoring data from the Pico W master control unit 1 through both the links established in the Wi-Fi configuration sub-area and the Bluetooth configuration sub-area. The host monitoring system 8 integrates data from any active link into the data visualization area for processing. Upon receiving a data packet from the Pico W master control unit 1, the host monitoring system 8 triggers the data parsing and graphics rendering process.

[0059] The host monitoring system 8 reads the standard JavaScript object musical notation string from the receive buffer. The host monitoring system 8 calls a JSON parser to convert the standard JavaScript object musical notation string into a key-value pair structure. The host monitoring system 8 extracts the ultraviolet (UV) level value, UV index value, light intensity value, and central processing unit (CPU) temperature value. The host monitoring system 8 obtains the current system time of the general-purpose computing device on which it resides. The host monitoring system 8 combines the current system time as a timestamp with the extracted monitoring data to generate a timestamped monitoring data record. The host monitoring system 8 stores the timestamped monitoring data record in a first-in-first-out (FIFO) display cache queue. The FIFO display cache queue maintains a fixed-length data window. When the FIFO display cache queue is full, the host monitoring system 8 removes the monitoring data record with the earliest timestamp.

[0060] The supervisory control system 8 constructs real-time data waveform charts. These charts include a horizontal axis and a vertical axis. The horizontal axis is configured as a time axis. The time span of the horizontal axis is determined by a preset time window parameter. The supervisory control system 8 updates the scale labels of the horizontal axis based on the timestamps of the time-stamped monitoring data records. The horizontal axis displays a real-time scrolling effect with second-level precision.

[0061] The host monitoring system 8 performs a fixed range configuration operation on the vertical axis. The host monitoring system 8 disables the automatic scaling function of the vertical axis. The automatic scaling function typically dynamically adjusts the axis range based on the maximum and minimum values ​​of the currently displayed data. The host monitoring system 8 locks the minimum value of the vertical axis to a preset lower limit. The host monitoring system 8 locks the maximum value of the vertical axis to a preset upper limit. For the display of UV index data, the preset lower limit is set to 0, and the preset upper limit is set to 15. The fixed range configuration operation ensures that the waveform amplitude of data over different time periods is intuitively comparable. The fixed range configuration operation prevents misleading visual magnification of the waveform caused by automatic scaling under low-value fluctuation conditions.

[0062] The supervisory control system 8 embeds a legend component within the plotting area of ​​the real-time data waveform chart. The legend component identifies the physical quantities represented by different colored data curves. The supervisory control system 8 sets the display position coordinates of the legend component in an inner corner of the plotting area. The supervisory control system 8 sets the background fill attribute of the legend component. The supervisory control system 8 sets the background transparency channel (Alpha Channel) value of the legend component to a decimal between 0 and 1. This background transparency channel setting gives the legend component a semi-transparent visual effect. This semi-transparent visual effect allows the grid lines and data curves located below the legend component to be observed through the background of the legend component. The embedded semi-transparent legend design eliminates the space occupied by a separate legend area in the plotting area. The embedded semi-transparent legend design maximizes the effective display area of ​​the real-time data waveform chart.

[0063] The supervisory control system 8 displays the numerical points in the first-in-first-out (FIFO) display cache queue and plots a continuous line on the real-time data waveform chart. The supervisory control system 8 refreshes the plotting area at a fixed frequency. This refresh operation enables dynamic visualization of the ultraviolet monitoring data. The intelligent data acquisition system's power-on self-test and network distribution process defines the initialization operation sequence of the dual-mode communication ultraviolet precision monitoring system based on an embedded microcontroller from the moment of power-on until it enters a stable monitoring state.

[0064] An external DC power supply is connected to the low-noise power management module 2. The low-noise power management module 2 outputs a stable DC operating voltage to the Pico W main control unit 1, the photoelectric acquisition front-end 3, the audible and visual alarm drive unit 4, and the human-machine interface display module 5. After power-on reset, the Pico W main control unit 1 executes the boot program. The Pico W main control unit 1 loads and runs the embedded firmware program. The Pico W main control unit 1 performs hardware peripheral initialization operations. The Pico W main control unit 1 configures the direction and initial level of the general-purpose input / output pins. The Pico W main control unit 1 sets the pin controlling the audible and visual alarm drive unit 4 to an inactive level to maintain a silent state. The Pico W main control unit 1 initializes the analog-to-digital converter interface. The Pico W main control unit 1 calibrates the reference voltage of the analog-to-digital converter interface. The Pico W main control unit 1 initializes the internal integrated circuit bus interface and the general asynchronous transceiver interface.

[0065] Pico W master unit 1 performs a file system mount operation. Pico W master unit 1 attempts to mount the LittleFS file system located in the Flash memory. If the mount operation fails, Pico W master unit 1 performs a file system formatting operation to repair the storage area. The file system mount operation ensures that the subsequent circular overwrite storage management mechanism can correctly read and write log files.

[0066] The Pico W main control unit 1 performs the initialization operation of the human-machine interface display module 5. The Pico W main control unit 1 sends a reset command and screen parameter configuration command to the OLED display screen via the internal integrated circuit bus. The OLED display screen clears its display buffer. The OLED display screen displays a system startup prompt message. The Pico W main control unit 1 starts the Net-WiFi communication module 6. The Net-WiFi communication module 6 reads the wireless network configuration parameters stored in the Flash file system. The wireless network configuration parameters include the service set identifier and password. The Net-WiFi communication module 6 attempts to connect to the wireless LAN access point based on the wireless network configuration parameters.

[0067] After the Net-WiFi communication module 6 successfully establishes a physical link connection, it initiates a Dynamic Host Configuration Protocol (DHCP) request. The Net-WiFi communication module 6 obtains the Internet Protocol address (IPC) assigned to the Pico W master control unit 1 from the network router. The Pico W master control unit 1 reads this IPC address. The Pico W master control unit 1 immediately invokes the human-machine interaction and display refresh logic. The Pico W master control unit 1 renders the IPC address onto the network status and addressing information area of ​​the OLED display screen. Directly displaying the IPC address on the OLED display screen solves the technical problem of embedded devices without screens or keyboards being difficult for the host computer to detect within a local area network.

[0068] After obtaining the Internet Protocol address, the Net-WiFi communication module 6 starts the Transmission Control Protocol (TCP) server listening program. The TCP server enters a connection waiting state. The Pico W main control unit 1 concurrently starts the Bluetooth communication module 7. The Bluetooth communication module 7 initializes the Bluetooth Low Energy protocol stack. The Bluetooth communication module 7 configures the Universal Access Profile broadcast parameters. The broadcast parameters include the device name and the device's unique identifier. The Bluetooth communication module 7 starts radio frequency broadcasting and enters a pairing connection waiting state.

[0069] Pico W main control unit 1 detects the initialization status of each functional module. Once Pico W main control unit 1 confirms that the file system, network service, and Bluetooth service are all started correctly, it determines that the system power-on self-test has passed. Pico W main control unit 1 then enters the main loop logic and begins executing periodic ultraviolet data acquisition and transmission tasks. The real-time monitoring and data transmission process is periodically scheduled and executed by Pico W main control unit 1. This real-time monitoring and data transmission process achieves closed-loop control from physical signal acquisition to multi-terminal data distribution.

[0070] Pico W main control unit 1 triggers a data acquisition task in response to a timer interrupt signal. Pico W main control unit 1 reads the analog voltage signal output from the photoelectric acquisition front-end 3 via an analog-to-digital converter interface. Pico W main control unit 1 performs multiple samplings and calculates the arithmetic mean to eliminate random noise interference. Pico W main control unit 1 reads the voltage value of the internal temperature sensor and converts it to a Celsius value. Pico W main control unit 1 calculates the real-time UV index based on the sampled analog voltage signal. Pico W main control unit 1 executes a safety alarm logic judgment based on the real-time UV index. The safety alarm logic judgment determines the alarm status using the following piecewise function formula: ; In the formula, This indicates the logic level state of the control signal for the audible and visual alarm drive unit 4. A value of 1 represents a high-level trigger state, and a value of 0 represents a low-level silent state. This represents the currently calculated real-time ultraviolet index value; This indicates the preset ultraviolet radiation safety threshold. When When the value is 1, the Pico W main control unit 1 outputs a high-level signal to the audible and visual alarm drive unit 4. The audible and visual alarm drive unit 4 then drives the buzzer to sound and the LED to flash. When the value is 0, the Pico W main control unit 1 outputs a low-level signal to the audible and visual alarm drive unit 4. The audible and visual alarm drive unit 4 remains in the off state.

[0071] Pico W main control unit 1 invokes the circular overwrite storage management mechanism. Pico W main control unit 1 writes records containing timestamps, UV levels, UV index, and temperature data to a log file in the Flash file system. Pico W main control unit 1 invokes the human-computer interaction and display refresh logic. Pico W main control unit 1 updates the numerical display content on the OLED screen. Pico W main control unit 1 performs data serialization. Pico W main control unit 1 encapsulates the collected multidimensional data into a standard JavaScript object abbreviation string according to the communication protocol data frame definition. Pico W main control unit 1 executes the wireless LAN transmission steps. Pico W main control unit 1 checks the client connection list of Net-WiFi communication module 6. When Net-WiFi communication module 6 detects a valid Transmission Control Protocol (TCP) client connection, Net-WiFi communication module 6 writes the standard JavaScript object abbreviation string to the network transmission buffer. Net-WiFi communication module 6 sends the data packet to the upper-level monitoring system 8 via the wireless LAN.

[0072] Pico W main control unit 1 executes the Bluetooth transmission steps. Pico W main control unit 1 checks the connection status of Bluetooth communication module 7. When Bluetooth communication module 7 is connected, it writes the standard JavaScript object notation string to the characteristic value of the general property configuration file. Bluetooth communication module 7 pushes data packets to the host monitoring system 8 or the mobile terminal via the Bluetooth Low Energy link.

[0073] Pico W main control unit 1 completes the data processing and transmission tasks for the current cycle. Pico W main control unit 1 enters a low-power idle state to wait for the next timer interrupt signal. The real-time monitoring and data transmission process ensures synchronous updates of monitoring data in four dimensions: local storage, local display, remote WiFi terminal, and near-field Bluetooth terminal.

[0074] This invention also provides specific implementation methods for the anomaly handling and offline operation process. The anomaly handling and offline operation process ensures the continuous and stable operation of the Pico W main control unit 1 in the event of communication link failure or the absence of a host computer.

[0075] The Pico W main control unit 1 polls the connection status of the Net-WiFi communication module 6 and the Bluetooth communication module 7 in real time during the main loop. When the Net-WiFi communication module 6 detects a loss of wireless LAN signal or an unexpected interruption of the Transmission Control Protocol socket connection, the Net-WiFi communication module 6 triggers a network exception interruption service routine. The network exception interruption service routine updates the network status flag to the disconnected state.

[0076] The Pico W main control unit 1 does not stop data acquisition during network anomalies. It maintains power supply and signal reading operations for the photoelectric acquisition front-end 3. The Pico W main control unit 1 continues to write the acquired monitoring data to the Flash storage file system. It ensures the continuity of data recording is unaffected by network fluctuations. The Net-WiFi communication module 6 executes an exponential backoff reconnection strategy. This strategy prevents the Pico W main control unit 1 from frequently consuming processor resources during network failures. The Net-WiFi communication module 6 calculates the waiting time interval for the next reconnection attempt. The waiting time interval is calculated using the following formula: ; In the formula, This indicates the time that the Net-WiFi communication module 6 needs to wait before performing the next reconnection operation; This represents the preset base waiting time constant; This represents the count of consecutive failed reconnections.

[0077] The Net-WiFi communication module 6 attempts to reconnect to the wireless access point after the waiting time interval expires. If the reconnection is successful, the Net-WiFi communication module 6 will... Reset. If reconnection fails, the Net-WiFi communication module 6 will add... The value continues until it reaches a preset upper limit. When the Pico W main control unit 1 cannot establish any external communication connection, the system automatically switches to offline operation mode. In offline operation mode, the human-machine interface display module 5 becomes the only data output interface. The Pico W main control unit 1 refreshes the ultraviolet index and system status in real time through the organic light-emitting diode display screen. The Pico W main control unit 1 relies on a cyclic overwrite storage management mechanism to store long-term historical data in the local Flash memory. Offline operation mode allows the device to independently complete the cumulative monitoring of ultraviolet radiation dose in outdoor environments without network access.

[0078] Pico W main control unit 1 activates its on-chip independent watchdog timer. This independent watchdog timer monitors the operational stability of the embedded software system. It has a preset overflow period. At the end of each iteration of the main loop, Pico W main control unit 1 executes a "feed the watchdog" instruction. This instruction resets the watchdog timer's counter. If Pico W main control unit 1 becomes stuck due to strong electromagnetic interference or software logic deadlock, it cannot execute the "feed the watchdog" instruction. The watchdog timer's counter continues to increment until it exceeds the preset overflow period. The watchdog timer then generates a system reset signal. This system reset signal forces Pico W main control unit 1 to restart and execute the system power-on self-test (POST) procedure. This independent watchdog mechanism enables automatic system fault recovery in unattended operation.

Claims

1. An intelligent data acquisition system based on a SiC ultraviolet photodetector, characterized in that, It includes a Pico W main control unit (1), a low-noise power management module (2), a photoelectric acquisition front end (3), an audible and visual alarm drive unit (4), a human-machine interaction display module (5), a Net-WiFi communication module (6), a Bluetooth communication module (7), and a host monitoring system (8). The Pico W main control unit (1) adopts the RP2040 microcontroller chip. The Pico W main control unit (1) establishes an electrical connection with the low-noise power management module (2), the photoelectric acquisition front end (3), the sound and light alarm drive unit (4) and the human-machine interaction display module (5) through the general input and output interface, analog-to-digital conversion interface and internal communication bus. The low-noise power management module (2) converts the input DC power into regulated DC power and outputs the regulated DC power to the photoelectric acquisition front end (3). The low-noise power management module (2) avoids the PicoW main control unit (1) through physical wiring and the power supply circuit of the onboard switching power supply to complete the physical isolation between the analog circuit power supply and the digital circuit power supply. The photoelectric acquisition front end (3) includes a photodiode, an operational amplifier and a feedback resistor to construct a transimpedance amplifier circuit architecture. The output terminal of the photoelectric acquisition front end (3) is connected to the analog-to-digital conversion pin of the Pico W main control unit (1). The Net-WiFi communication module (6) and the Bluetooth communication module (7) establish a remote data transmission link and a near-field data transmission link respectively based on the radio frequency core of the Pico W main control unit (1) to transmit monitoring data to the upper-level monitoring system (8).

2. The intelligent data acquisition system based on a SiC ultraviolet photodetector according to claim 1, characterized in that, The low-noise power management module (2) includes a low-dropout linear regulator chip, an input filter capacitor, and an output voltage regulator capacitor. The input filter capacitor is connected across the voltage input pin of the low dropout linear regulator chip and the analog ground network. The output voltage regulator capacitor is connected across the voltage output pin of the low dropout linear regulator chip and the analog ground network. The voltage output pin of the low dropout linear regulator chip is directly connected to the power port of the photoelectric acquisition front end (3) through the printed circuit board trace; The output voltage of the low-noise power management module (2) does not pass through the switch-mode power converter inside the Pico W main control unit (1).

3. The intelligent data acquisition system based on a SiC ultraviolet photodetector according to claim 1, characterized in that, The photoelectric acquisition front end (3) does not include a voltage divider resistor connected in parallel in the feedback loop, and the feedback loop is composed of the feedback resistor; The cathode of the photodiode is connected to the regulated positive power supply output by the low-noise power management module (2), and the photodiode operates in photoconductive mode under reverse voltage. The analog voltage value collected by the Pico W main control unit (1) is equal to the product of the instantaneous photocurrent value generated by the photodiode and the resistance value of the feedback resistor.

4. The intelligent data acquisition system based on a SiC ultraviolet photodetector according to claim 1, characterized in that, The sound and light alarm driving unit (4) includes a buzzer, a light-emitting diode and a transistor driving circuit; The sound and light alarm drive unit (4) removes the filter capacitors connected in parallel across the buzzer and across the light-emitting diode to eliminate the capacitor discharge surge current generated at the moment the electronic switching element is turned on. The control terminal of the transistor driving circuit is connected to the general-purpose input / output pin of the Pico W main control unit (1), the input terminal of the transistor driving circuit is connected to the negative terminal of the buzzer and the cathode of the light-emitting diode, and the output terminal of the transistor driving circuit is connected to the digital ground network.

5. The intelligent data acquisition system based on a SiC ultraviolet photodetector according to claim 1, characterized in that, The Net-WiFi communication module (6) is used to establish a transmission control protocol server and enable port multiplexing function; The Net-WiFi communication module (6) sets the SO_REUSEADDR option of the network socket object to the enabled state, so that the Net-WiFi communication module (6) can immediately rebind the network port after the Pico W master control unit (1) performs a soft reboot operation; The Net-WiFi communication module (6) calls the listening function to put the network socket object into a passive listening state and sets the maximum length parameter of the suspended connection queue to 1, so as to accept the single-point connection request of the upper-level monitoring system (8).

6. The intelligent data acquisition system based on a SiC ultraviolet photodetector according to claim 1, characterized in that, The Bluetooth communication module (7) adopts an application-layer big data fragmentation transmission mechanism; When the total byte length of the data packet to be sent exceeds the payload length allowed by the maximum transmission unit value, the Bluetooth communication module (7) calculates the required total number of fragments by rounding up the ratio of the total byte length of the data packet to be sent to the maximum transmission unit value of the Bluetooth connection. The Bluetooth communication module (7) divides the data packet to be sent into multiple sub-data segments according to the total number of fragments and inserts a custom protocol header containing the current fragment sequence number and the total number of fragments at the beginning of each sub-data segment.

7. The intelligent data acquisition system based on a SiC ultraviolet photodetector according to claim 1, characterized in that, The Pico W main control unit (1) operates a cyclic overlay storage management mechanism; When the Pico W main control unit (1) generates a new monitoring data record, the circular overlay storage management mechanism reads all historical data lines stored in the target log file and calculates the total number of current historical data lines; When the total number of rows is greater than or equal to the preset maximum record threshold, the circular overlay storage management mechanism determines the starting index position of the truncation operation according to the preset retention quantity parameter; The circular overlay storage management mechanism extracts data rows from the starting index position to the end of the historical data row list to form a retained data list, and appends the new monitoring data record to the end of the retained data list.

8. The intelligent data acquisition system based on a SiC ultraviolet photodetector according to claim 1, characterized in that, The human-computer interaction display module (5) performs the display frame construction step; The human-computer interaction display module (5) renders the ultraviolet level value to the first display line, renders the internal temperature sensor value of the Pico W main control unit (1) to the second display line, renders the connection status and dynamically acquired Internet Protocol address of the Net-WiFi communication module (6) to the third and fourth display lines, and renders the status, number of stored data points and system running time of the Bluetooth communication module (7) to the fifth and sixth display lines. The human-computer interaction display module (5) performs a video memory clearing operation to clear the residual pixel data displayed in the previous frame.

9. The intelligent data acquisition system based on a SiC ultraviolet photodetector according to claim 1, characterized in that, The Pico W main control unit (1) encapsulates communication protocol data frames using a JavaScript object simplified spectrum structure and sends them to the upper-level monitoring system (8). The upper-level monitoring system (8) constructs a graphical user interface, which is divided into a communication configuration area and a data visualization area. The upper-level monitoring system (8) parses the received communication protocol data frames and constructs real-time data waveform charts in the data visualization area. The communication protocol data frame includes a UV level field, a UV index field, a light intensity field, and a central processing unit temperature field. The ultraviolet index field represents a value calculated based on the output voltage of the photoelectric acquisition front-end (3), the proportional conversion coefficient calibrated for specific spectral response characteristics, and the zero-point drift compensation value. The light intensity field represents the original analog voltage value collected by the Pico W main control unit (1); The central processing unit temperature field represents the chip junction temperature value read from the internal temperature sensor of the Pico W main control unit (1).

10. The intelligent data acquisition system based on a SiC ultraviolet photodetector according to claim 4, characterized in that, The Pico W main control unit (1) calculates the real-time ultraviolet index value based on the sampled analog voltage signal and performs a safety alarm logic judgment. When the real-time ultraviolet index value is greater than or equal to the preset ultraviolet radiation safety threshold, the Pico W main control unit (1) outputs a high-level signal to the sound and light alarm drive unit (4) to drive the buzzer to sound and the light-emitting diode to flash. When the real-time ultraviolet index value is less than the preset ultraviolet radiation safety threshold, the Pico W main control unit (1) outputs a low-level signal to the sound and light alarm drive unit (4) to maintain a silent state.

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