A non-contact wireless food thermometer for multi-point temperature measurement

Abstract

This application proposes a non-contact wireless food thermometer for multi-point temperature measurement, comprising a housing and a circuit board disposed within the housing. The circuit board includes: a temperature detection module, including at least one digital temperature sensor based on the bipolar transistor principle, for collecting temperature information of the food; a main control communication module electrically connected to the temperature detection module via a shared bus, for receiving temperature information and performing wireless communication; a power supply module electrically connected to both the temperature detection module and the main control communication module, for providing operating power to both modules; and an ESD protection structure disposed at the power input and signal input / output terminals of the wireless food thermometer. This application enables effective acquisition and wireless transmission of food temperature, while improving the device's anti-static capability and power supply stability, effectively solving the problems of insufficient temperature detection accuracy and stability in existing technologies.

Description

Technical Field

[0001] This application relates to the field of temperature measurement technology, and in particular to a non-contact wireless food thermometer for multi-point temperature measurement. Background Technology

[0002] With the improvement of living standards, people are paying more and more attention to temperature monitoring during food processing. Wireless food thermometers are widely used because they can achieve non-contact data reading and facilitate continuous monitoring of the internal temperature of food. At present, most wireless food thermometers on the market adopt a contact temperature measurement solution, which collects the temperature of food through a temperature detection module, and then the main control communication module wirelessly transmits the temperature information to the terminal device, while relying on a power module to provide working power.

[0003] However, existing temperature detection modules often employ sensors such as semiconductor thermistors, thermocouples, or platinum resistance thermometers. These sensors, limited by their inherent characteristics, generally suffer from significant non-linear relationships between temperature and electrical signals, low sensitivity, and susceptibility to external circuit interference. This results in poor temperature measurement accuracy and repeatability, failing to meet the precision requirements of food processing. Furthermore, when multiple points need to be measured at different parts of the food, the connection between the sensor and the main control module consumes substantial interface resources, increasing circuit design complexity and potentially affecting data transmission stability due to interface conflicts. Therefore, existing temperature sensors suffer from insufficient temperature detection accuracy and stability.

[0004] The preceding description is intended to provide general background information and does not necessarily constitute prior art. Utility Model Content

[0005] To address the aforementioned technical issues, this application provides a non-contact wireless food thermometer for multi-point temperature measurement, which can effectively collect and wirelessly transmit food temperature, while improving the device's anti-static capability and power supply stability, effectively solving the problems of insufficient temperature detection accuracy and stability in existing technologies.

[0006] In a first aspect, this application provides a non-contact wireless food thermometer for multi-point temperature measurement, including a housing and a circuit board disposed within the housing, the circuit board comprising: The temperature detection module includes at least one digital temperature sensor based on the bipolar transistor principle, used to collect temperature information of the food. The main control communication module is electrically connected to the temperature detection module via a shared bus, and is used to receive temperature information collected by the temperature detection module and perform wireless communication. The power supply module is electrically connected to the temperature detection module and the main control communication module respectively, and is used to provide working power to the temperature detection module and the main control communication module; The ESD protection structure is located at the power input terminal and signal input / output terminal of the non-contact wireless food thermometer used for multi-point temperature measurement.

[0007] Furthermore, in some embodiments of this application, the digital temperature sensor integrates a temperature sensing unit, a signal processing unit, and an interface unit, and the interface unit is connected to the shared bus; multiple digital temperature sensors are connected in parallel through the shared bus, and all are electrically connected to the same bus interface of the main control communication module.

[0008] Furthermore, in some embodiments of this application, the main control communication module is a Bluetooth chip, the Bluetooth chip is connected to the digital temperature sensor through the shared bus, and multiple digital temperature sensors are electrically connected to the same bus interface of the Bluetooth chip; the Bluetooth chip is a BLE protocol Bluetooth chip integrating a main control unit, an ADC unit, a storage unit and an internal temperature measurement unit, the input terminal of the ADC unit is electrically connected to the output terminal of the power module, the storage unit is a Flash memory or an OTP memory, and the internal temperature measurement unit is electrically connected to the main control unit of the Bluetooth chip.

[0009] Furthermore, in some embodiments of this application, the shared bus is an IIC bus or a single bus, and the interface unit of the digital temperature sensor is an IIC interface adapted to the IIC bus, or a single bus interface adapted to the single bus.

[0010] Furthermore, in some embodiments of this application, the signal processing unit includes a filter, an amplifier, and an A / D converter. The output terminal of the temperature sensing unit is electrically connected to the input terminal of the A / D converter in sequence through the filter and the amplifier. The output terminal of the A / D converter is electrically connected to the interface unit.

[0011] Furthermore, in some embodiments of this application, the Bluetooth chip also integrates a multiplexer, the input of which is electrically connected to the shared bus, and the output of which is electrically connected to the main control unit of the Bluetooth chip.

[0012] Furthermore, in some embodiments of this application, the power module includes an energy storage element and a voltage conversion unit, and the output terminal of the energy storage element is electrically connected to the temperature detection module and the main control communication module respectively through the voltage conversion unit; The energy storage element is a lithium-ion supercapacitor. The power module also includes a charge and discharge protection circuit, which is electrically connected to the lithium-ion supercapacitor and is used to provide overcharge protection, over-discharge protection, over-temperature protection, overcurrent protection, and short-circuit protection for the lithium-ion supercapacitor.

[0013] Furthermore, in some embodiments of this application, the voltage conversion unit is an LDO regulator or a DC-DC converter, the input terminal of the voltage conversion unit is electrically connected to an external charging power supply or the energy storage element, and the output terminal of the voltage conversion unit outputs a working voltage adapted to the temperature detection module and the main control communication module.

[0014] Furthermore, in some embodiments of this application, the ESD protection structure includes a protection diode, which is disposed at the power input terminal and the signal input / output terminal, and the protection diode is disposed close to the ports of the power input terminal and the signal input / output terminal.

[0015] Furthermore, in some embodiments of this application, the circuit board is a four-layer PCB board, the PCB board is provided with a ground line, and the edge of the PCB board is provided with a metal edging, the metal edging being electrically connected to the ground line.

[0016] Furthermore, in some embodiments of this application, the non-contact wireless food thermometer for multi-point temperature measurement further includes a housing, the housing being made of a conductive material or having a conductive coating on its surface, and the housing being electrically connected to the ground wire of the PCB board. Implementing the embodiments of this application has the following beneficial effects: This application provides a non-contact wireless food thermometer for multi-point temperature measurement. The temperature detection module employs a digital temperature sensor based on the bipolar transistor principle, featuring small size, good linearity, high accuracy, and low power consumption, enabling accurate acquisition of food temperatures at multiple points. The temperature detection module and the main control communication module are connected via a shared bus, reducing the interface occupancy and wiring complexity of the main control communication module, effectively solving the problem of requiring more I / O resources for multi-point temperature measurement, and ensuring efficient transmission of temperature information. The main control communication module is responsible for receiving temperature information and realizing wireless communication, ensuring stable data transmission. A power supply module provides stable power support to each module. Furthermore, ESD protection structures are installed at the power supply and signal input / output terminals, effectively resisting electrostatic discharge and overstress damage. Therefore, this application can achieve effective acquisition and wireless transmission of food temperature, while improving the device's anti-static capability and power supply stability, effectively solving the problems of insufficient temperature detection accuracy and stability in existing technologies. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a non-contact wireless food thermometer for multi-point temperature measurement provided in an embodiment of this application; Figure 2 This is a schematic diagram of the internal circuit principle of a non-contact wireless food thermometer for multi-point temperature measurement provided in an embodiment of this application.

[0019] Among them, 10 is the housing; 20 is the circuit board; 201 is the temperature detection module; 202 is the main control communication module; 203 is the power supply module; and 204 is the ESD protection structure.

[0020] The realization of the objectives, functional features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and textual descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0022] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0023] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0024] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.

[0025] Please see Figure 1 , Figure 1 This is a schematic diagram of a non-contact wireless food thermometer for multi-point temperature measurement provided in an embodiment of this application. The non-contact wireless food thermometer for multi-point temperature measurement provided in this embodiment includes a housing 10 and a circuit board 20 disposed within the housing; Specifically, the housing 10 provides physical protection and food contact safety for the entire device. It is made of food-grade high-temperature resistant materials (such as polytetrafluoroethylene or high-temperature resistant silicone), and its shape is adaptable to common food containers (such as baking pans, saucepans, etc.), allowing direct contact with food without producing harmful substances. The housing has internal slots and positioning posts to secure the circuit board, preventing components from falling off or causing poor wiring contact due to vibration during use. The housing surface is also treated to prevent oil stains, facilitating cleaning and maintenance.

[0026] Specifically, circuit board 20, serving as the carrier for each functional module, is made of FR4 epoxy glass cloth substrate, possessing excellent insulation and mechanical strength. The circuit board surface is treated with immersion gold to enhance the solder joints' oxidation resistance and conductivity. Module components (such as sensors, chips, and capacitors) are soldered onto pre-set pads on the circuit board using surface mount technology (SMT). This compact layout adheres to electromagnetic compatibility (EMC) design principles, reducing signal interference between modules and ensuring stable circuit operation.

[0027] The circuit board 20 includes: Temperature detection module 201 includes at least one digital temperature sensor based on the principle of bipolar transistor, used to collect temperature information of food; Specifically, for the temperature detection module 201, the temperature detection module is the core temperature measurement unit of the device, and its core component is a digital temperature sensor based on the bipolar transistor principle. This sensor integrates a bipolar transistor core, a signal amplification circuit, and an A / D conversion (Analog-to-Digital Conversion) unit: the conduction voltage of the bipolar transistor changes linearly with temperature, and the temperature value can be directly reflected by detecting its voltage change; the signal amplification circuit amplifies the weak voltage signal to a recognizable range; the A / D conversion unit converts the analog signal into a digital signal for easy processing by the main control module. The temperature detection module and the main control communication module are electrically connected via a shared bus (such as an I2C bus), requiring only two signal lines (SDA data line and SCL clock line) to complete data transmission. Compared with traditional multi-line connection methods, this significantly reduces circuit board wiring space, lowers the risk of line interference, and saves I / O interface resources of the main control module, making the circuit design simpler.

[0028] The main control communication module 202 is electrically connected to the temperature detection module via a shared bus, and is used to receive temperature information collected by the temperature detection module and perform wireless communication. Specifically, the main control communication module 202 is responsible for data processing and wireless transmission, including a microcontroller unit (MCU) and a wireless communication unit. The MCU uses a low-power microcontroller (such as the STM32L series), with a built-in arithmetic logic unit (ALU) and memory. It receives digital temperature signals transmitted from the temperature detection module, performs filtering and calibration, and generates standard temperature data. The wireless communication unit integrates a Bluetooth BLE module (such as the CC2541 chip), which transmits wireless signals via a PCB antenna, allowing real-time transmission of temperature data to external receiving devices (such as mobile phones and smart terminals). The main control communication module and the temperature detection module achieve bidirectional communication via a shared bus (the MCU sends control commands to the sensor, and the sensor feeds back temperature data to the MCU). It connects to the power supply module via power pins to obtain the operating voltage. Impedance matching resistors are incorporated into its circuit design to ensure stable wireless signal transmission and reduce packet loss.

[0029] The power supply module 203 is electrically connected to the temperature detection module and the main control communication module respectively, and is used to provide working power to the temperature detection module and the main control communication module; Specifically, for power module 203, the power module provides stable power support for the entire device, including a power supply unit and a voltage conversion unit. The power supply unit uses lithium-ion supercapacitors (capacity 2-10mAh), which have the advantages of more charge / discharge cycles and better low-temperature performance compared to traditional batteries, making them suitable for the high and low temperature environments of food processing. The voltage conversion unit integrates a low-dropout linear regulator (LDO, such as the XC6206 chip), which can stably output the 3.3-5V voltage from the supercapacitor to 3.0V, powering sensitive components such as the temperature detection module and the main control communication module, avoiding measurement errors or module damage caused by voltage fluctuations. The power module is connected to the power input terminals of other modules via a power cord. A self-resetting fuse is connected in series in the circuit, which automatically disconnects when an overcurrent occurs to protect the module. At the same time, it adopts a low-power design (standby current <10μA) to extend the usage time of the device after a single charge. ESD protection structure 204, the ESD protection structure is disposed at the power input terminal and signal input / output terminal of the non-contact wireless food thermometer for multi-point temperature measurement; Specifically, the ESD (Electrostatic Discharge) protection structure 204 is used to protect the equipment from damage caused by electrostatic discharge (ESD), including ESD protection diodes (such as the SMBJ series) and a grounding network. The ESD protection diodes are connected in parallel to the power input terminal and signal input / output terminals (such as shared bus interfaces and wireless communication antenna interfaces). Their breakdown voltage is slightly higher than the module's operating voltage. When an electrostatic shock causes a voltage surge, the diodes quickly conduct, diverting the electrostatic energy into the grounding network. The grounding network consists of a large area of ​​grounding copper foil on the circuit board, connected to the metal shielding layer of the casing, which can quickly release electrostatic charge and prevent electrostatic breakdown of sensitive components such as temperature sensors and wireless communication chips.

[0030] This embodiment achieves safe contact between the device and food, as well as physical protection for internal components, through the structural design of the housing; the rational layout and processing of the circuit board reduce interference between modules; the temperature detection module uses a digital sensor based on the bipolar transistor principle and is connected via a shared bus, improving temperature measurement accuracy and circuit integration; the main control communication module enables efficient processing and stable wireless transmission of temperature data; the low-power design and voltage regulation function of the power module ensure the device's battery life and operational stability; and the ESD protection structure effectively resists electrostatic damage. Therefore, this embodiment achieves high-precision acquisition of food temperature and low-power wireless transmission, while possessing good anti-static capabilities and environmental adaptability, thereby improving the practicality and reliability of the equipment.

[0031] Furthermore, in some embodiments, the digital temperature sensor integrates a temperature sensing unit, a signal processing unit, and an interface unit, with the interface unit connected to the shared bus; multiple digital temperature sensors are connected in parallel through the shared bus, and all are electrically connected to the same bus interface of the main control communication module.

[0032] Specifically, the digital temperature sensor in this embodiment is manufactured using advanced semiconductor process technology (such as 22nm process), and its size can be controlled within 111mm. It integrates a temperature sensing unit, a signal processing unit, and an interface unit. Each unit is electrically connected through internal metal wiring, and the whole is packaged as a surface mount structure, which is convenient for high-density layout on the circuit board.

[0033] The core of the temperature sensing unit is a BJT (Bipolar Junction Transistor) based temperature sensing unit, composed of an NPN transistor and a bias circuit. The base-emitter voltage (Vbe) of a BJT transistor exhibits a significant temperature dependence, decreasing linearly with increasing temperature, directly converting temperature changes in food into a measurable analog electrical signal. This unit achieves low-power design through micro-current drive, reducing the impact of self-heating on temperature measurement accuracy and ensuring accuracy when measuring low or high internal temperatures within food.

[0034] The signal processing unit is connected in series with the output of the temperature sensing unit, and includes a filter, an amplifier and an A / D converter in sequence to form a complete signal chain.

[0035] The interface unit serves as a bridge connecting the digital temperature sensor to the external shared bus, comprising a protocol controller, a level conversion circuit, and pin interfaces. The protocol controller incorporates IIC or single-bus communication protocol logic, capable of parsing address commands (distinguishing between different sensors) and data read commands sent by the main control communication module. The level conversion circuit converts the sensor's internal 3.3V signal to a level compatible with the shared bus (e.g., 5V), ensuring compatible communication between devices in different voltage domains. The pin interfaces consist of two (IIC protocol) or one (single-bus protocol) metal pins, physically connected to the shared bus via circuit board wiring, enabling bidirectional data transmission.

[0036] In this embodiment, multiple digital temperature sensors (the number can be set from 2 to 8 as needed) are connected in parallel to a shared bus, and all are connected to the main control communication module through the same bus interface. The specific connection logic is as follows: The shared bus is a set of parallel conductive copper foils containing data lines (SDA) and clock lines (IIC protocol) or a single signal line (single bus protocol). Both ends of the bus are equipped with terminating matching resistors (10kΩ) to reduce transmission errors caused by signal reflection and impedance mismatch.

[0037] Each digital temperature sensor's interface unit pins (data lines and clock lines) are connected to the corresponding copper foil on the shared bus: the data line pins are connected in parallel to the bus's data lines, and the clock line pins are connected in parallel to the bus's clock lines (IIC protocol), or the single signal line pins are connected in parallel to a single signal line on the bus (single bus protocol). This parallel connection method allows all sensors to share the same set of transmission lines, eliminating the need for separate wiring for each sensor and significantly simplifying circuit board routing.

[0038] One end of the shared bus is directly connected to the same bus interface of the main control communication module. This interface has a built-in bus controller, which can select a specific digital temperature sensor by sending an instruction with an address code (such as a 7-bit address of the IIC protocol) to achieve "one-to-many" communication control: after the main control module sends the address instruction, only the sensor that matches the address responds and transmits data, while other sensors are in a listening state to avoid data conflicts.

[0039] This embodiment achieves significant technical improvements by optimizing the internal integrated structure of the digital temperature sensor and the bus connection method of multiple sensors: the linear characteristics of the temperature sensing unit based on the BJT principle and the filtering, amplification, and high-precision conversion functions of the signal processing unit greatly improve the original accuracy and anti-interference capability of the temperature signal; the adaptation design of the interface unit and the shared bus ensures stable communication between the sensor and the main control module; the parallel connection of multiple sensors and the access method of the same bus interface completely solve the problem that traditional multi-point temperature measurement requires a large amount of main control IO resources, while simplifying circuit wiring, reducing the risk of line interference, and enabling the device to flexibly expand the temperature measurement points (such as simultaneously measuring the surface, center, and edge temperature of food). While ensuring high-precision temperature measurement, it significantly improves the integration, scalability, and communication stability of the device, meeting the needs of complex food temperature measurement scenarios.

[0040] Furthermore, in some embodiments, the main control communication module is a Bluetooth chip, and the Bluetooth chip is connected to the digital temperature sensor through the shared bus. Multiple digital temperature sensors are electrically connected to the same bus interface of the Bluetooth chip. The Bluetooth chip is a BLE protocol Bluetooth chip integrating a main control unit, an ADC unit, a storage unit, and an internal temperature measurement unit. The input terminal of the ADC unit is electrically connected to the output terminal of the power module. The storage unit is a Flash memory or an OTP memory. The internal temperature measurement unit is electrically connected to the main control unit of the Bluetooth chip.

[0041] Specifically, in this embodiment, the main control communication module uses a Bluetooth chip (such as the Nordic RF52832 series) compliant with the BLE (Bluetooth Low Energy) protocol. This chip is based on an ARM Cortex-M4 core, uses an advanced CMOS process (such as 40nm), operates within a voltage range of 1.8-3.6V, and has a power consumption as low as 0.5μA in idle mode, only 5.5mA in transmit mode (0dBm), and 6.9mA in receive mode, significantly lower than traditional Bluetooth chips, thus meeting the low-power requirements of devices. For example, the chip can be packaged as a WLCSP package (3.0mm×3.2mm), allowing for high-density soldering onto the circuit board, reducing space occupation and reserving more space for multi-sensor layouts. The Bluetooth chip internally integrates a main control unit, an ADC unit, a storage unit, and an internal temperature measurement unit. These units are interconnected via an internal chip bus (such as the AHB bus) to achieve high-speed data transmission and collaborative operation.

[0042] The main control unit, as the core control hub of the entire device, includes a 32-bit microprocessor (MCU), timers, an interrupt controller, and a peripheral interface controller. The MCU can quickly execute temperature data parsing, sensor control commands, and wireless communication protocol processing. Timers are used to generate precise timing sequences to ensure the synchronization of data acquisition from multiple sensors; the interrupt controller can respond to events such as sensor data readiness and abnormal power supply voltage, enabling real-time processing and avoiding data delays. It connects to other integrated units on the chip via an internal bus and is electrically connected to a shared bus (connecting to the digital temperature sensor) via external pins, undertaking the entire process control of "command sending - data receiving - processing - transmission".

[0043] The ADC unit is a 12-bit successive approximation analog-to-digital converter with an integrated programmable gain amplifier (PGA). It boasts a maximum sampling rate of 1 MSPS and supports eight analog input channels. Its input terminals are electrically connected to the output terminals of the power module (such as the voltage output point of a lithium-ion supercapacitor) via circuit board wiring, enabling real-time acquisition of the power module's output voltage. By converting the analog voltage signal into a digital signal, the main control unit can calculate the remaining power supply capacity based on a preset algorithm and trigger a low-power warning when the battery is low, preventing sudden power outages. Simultaneously, it can monitor power voltage fluctuations to ensure stable output from the voltage conversion unit, guaranteeing the operational stability of the sensor and the chip itself.

[0044] The storage unit includes Flash memory and OTP (One-Time Programmable) memory, both connected to the main control unit via an internal memory controller. The Flash memory has a capacity of up to 512KB, supports multiple erase and write operations, and is used to store device runtime programs and user configuration parameters, facilitating program updates and data rollback. The OTP memory only supports one-time programming and is used to store fixed parameters (such as sensor calibration coefficients and the chip's unique identifier ID). Because OTP requires no refresh operation and has low read power consumption, it reduces storage access power consumption during device operation, extending battery life.

[0045] The internal temperature sensing unit is designed based on the principles of PN junctions and BJT bipolar transistors, and includes a temperature sensing diode, a bias circuit, and a signal conditioning circuit. The forward voltage drop of the sensing diode exhibits a linear characteristic with temperature change, and the bias circuit provides a stable micro-current to ensure stable characteristics. The signal conditioning circuit filters (removes high-frequency noise) and amplifies the original signal, outputting an analog signal that linearly corresponds to the temperature, which is then converted into a digital signal by the chip's internal ADC. This unit is electrically connected to the main control unit via an internal bus and can output the chip's own temperature in real time. On one hand, it can serve as an "auxiliary point" for food temperature measurement (e.g., when a digital temperature sensor is inserted into food, the internal temperature sensing unit can simultaneously monitor the external ambient temperature of the food, forming temperature gradient data); on the other hand, it can be used for chip self-calibration (e.g., compensating for calculation errors caused by temperature changes in the chip), improving overall temperature measurement accuracy.

[0046] In this embodiment, multiple digital temperature sensors are electrically connected to the same bus interface of the Bluetooth chip via a shared bus (IIC or single bus). The Bluetooth chip's bus interface is a dedicated hardware IIC / SPI interface, including SDA (data) and SCL (clock) pins (IIC protocol), which are connected to the corresponding lines of the shared bus via circuit board wiring. The master control unit sends address-encoded commands to the shared bus through the bus interface: when data from a specific sensor needs to be acquired, the address in the command matches the preset address of that sensor, and the sensor responds and returns temperature data through the bus; other sensors remain silent due to address mismatches to avoid data conflicts. This "one master, many slaves" communication architecture can control and acquire data from multiple sensors using only two lines, saving more than 80% of I / O resources compared to traditional "one-to-one" I / O connections, while also reducing electromagnetic interference between lines and improving communication stability.

[0047] This embodiment significantly reduces energy consumption in wireless communication by employing a BLE protocol Bluetooth chip and integrating multiple units. Combined with the chip's low-power mode, this extends device battery life. The main control unit's efficient processing capabilities ensure real-time temperature data analysis and sensor control, improving response speed. The ADC unit monitors power status in real time, ensuring stable power supply. The internal temperature measurement unit adds auxiliary temperature measurement points, enhancing adaptability to various temperature measurement scenarios. Furthermore, the connection method with multiple sensors via the same bus interface saves I / O resources while ensuring stable communication.

[0048] Furthermore, in some embodiments, the shared bus is an IIC bus or a single bus, and the interface unit of the digital temperature sensor is an IIC interface adapted to the IIC bus, or a single bus interface adapted to the single bus.

[0049] Specifically, the shared bus serves as the data transmission channel between the digital temperature sensor and the main control communication module. It adopts a mature, standardized bus protocol in the industry, including two types: IIC bus and single bus. Its structural design is adapted to the parallel communication needs of multiple sensors.

[0050] For the IIC bus, a two-wire structure is adopted, including one data line (SDA) and one clock line (SCL), both of which are bidirectional transmission lines. The data line is responsible for the bidirectional transmission of temperature data and control commands, while the clock line is provided with a synchronization clock signal by the master control communication module (such as a Bluetooth chip) to ensure consistent communication timing between the master and slave devices (master control module and sensor). The bus lines use copper foil wiring on the PCB board, with 10kΩ pull-up resistors connected in parallel at both ends to the positive power supply, keeping the bus at a high level when idle and reducing signal noise interference. Simultaneously, parallel routing with high-frequency signal lines is avoided to reduce electromagnetic coupling interference and ensure data transmission integrity. For the single-bus, a one-wire structure is adopted, using only one data line for data transmission and power supply. This bus combines data communication and timing synchronization functions. The communication timing is controlled by the master control module through specific level pulses, eliminating the need for a separate clock line and further simplifying circuit wiring. The bus lines also use copper foil wiring and are connected in series with a 5kΩ current-limiting resistor to prevent damage to the master control module interface in case of sensor short circuits, improving bus safety.

[0051] The interface unit of the digital temperature sensor serves as the physical connection port between the sensor and the shared bus. Its circuit design is strictly adapted to the shared bus type to ensure communication protocol compatibility. The IIC interface unit, compatible with the IIC bus, integrates an IIC protocol controller, level conversion circuitry, and pin terminals. The protocol controller incorporates IIC communication logic (such as start / stop signal detection, address matching, and data verification), capable of parsing 7-bit / 10-bit address instructions (used to distinguish multiple sensors) and read / write instructions sent by the main control module. The level conversion circuit converts the sensor's internal 3.3V logic level to a level compatible with the IIC bus (supporting 3.3V / 5V mixed voltage systems), avoiding signal distortion when connecting devices with different voltage domains. The pin terminals consist of two independent metal pins (corresponding to SDA and SCL respectively), connected to the IIC bus lines on the PCB board via pads to achieve electrical connection between the sensor and the bus. The single-bus interface unit, compatible with a single-bus interface, integrates a single-bus protocol controller, parasitic power supply circuitry, and pin terminals. The protocol controller can recognize the reset pulse (used for initializing communication), ROM instructions (used for reading the sensor's unique ID), and function instructions (used for starting temperature measurement and reading data) sent by the main control module, and feed back temperature data according to the single bus timing rules; the parasitic power supply circuit allows the sensor to obtain a weak current through the data line when the bus is idle, which is suitable for low power consumption scenarios; the pin terminal is a single metal pin, which is directly connected to the single bus line, and completes data transmission and reception and power supply through the same line.

[0052] When multiple digital temperature sensors' IIC interfaces are connected to the IIC bus in parallel, the SDA pins of all sensors are connected to the SDA line of the bus, and the SCL pins are connected to the SCL line of the bus. The bus then connects to the IIC interface of the main control communication module. During communication, the main control module sends a clock signal via the SCL line and a command with the target sensor address via the SDA line. Only sensors with matching addresses will respond to the command (e.g., return temperature data), while other sensors remain in listening mode to avoid data conflicts and meet the expanded requirements for multi-point temperature measurement of food (e.g., different ingredients, or different parts of the same ingredient).

[0053] When multiple digital temperature sensors have their single-bus interfaces connected to a single bus in parallel, all sensors' single-bus pins are connected to the bus's signal line, which in turn connects to the main control communication module's single-bus interface. During communication, the main control module first sends a reset pulse, which all sensors on the bus will respond with a pulse to confirm the connection. Then, the main control module sends ROM instructions to identify the target device using the sensor's unique 64-bit ID. Finally, it sends function instructions to achieve temperature control and data reading. This mechanism distinguishes sensors using unique IDs, eliminating the need for manual address setting and simplifying the deployment process for multiple sensors.

[0054] This embodiment utilizes the two-wire structure and clock synchronization mechanism of the IIC bus to ensure high reliability and real-time performance of multi-sensor data transmission, adapting to high-precision temperature measurement scenarios. The single-wire structure of the single bus significantly simplifies circuit wiring, reduces hardware costs, and adapts to the needs of low-cost, small-size devices. Both buses support parallel sharing of multiple sensors, completely solving the problem of requiring a large number of I / O resources in traditional multi-point temperature measurement and improving the scalability of the device. The strict compatibility between the interface unit and the bus ensures the compatibility of communication protocols and reduces signal transmission errors.

[0055] Furthermore, in some embodiments, the signal processing unit includes a filter, an amplifier, and an A / D converter. The output terminal of the temperature sensing unit is electrically connected to the input terminal of the A / D converter in sequence through the filter and the amplifier. The output terminal of the A / D converter is electrically connected to the interface unit.

[0056] Specifically, the signal processing unit in this embodiment may include a filter, an amplifier, and an A / D converter.

[0057] The filter, the first-stage module of the signal processing unit, is connected in series with the output of the temperature sensing unit. Its core function is to filter out noise interference in the temperature signal, ensuring the purity of the signal in subsequent processing. The filter circuit employs an RC low-pass filter, composed of high-precision surface-mount resistors and ceramic capacitors, using the charging and discharging characteristics of the resistors and capacitors to form a specific cutoff frequency. This structure eliminates the need for complex active components, achieving filtering only through passive components, thus reducing the sensor's power consumption. The filter's input is directly electrically connected to the output of the temperature sensing unit via internal metal wiring, receiving the raw analog signal from the temperature sensing unit; the output is electrically connected to the input of the amplifier, transmitting the filtered signal to the next module. This targeted filtering of high-frequency electromagnetic interference and inherent circuit noise improves the signal-to-noise ratio, providing a high-quality raw signal for subsequent amplification and conversion.

[0058] The amplifier, an intermediate module in the signal processing unit, is connected in series between the filter and the A / D converter. Its core function is to amplify the filtered weak signal to a range that the A / D converter can accurately recognize, preventing the loss of accuracy during transmission and conversion of small signals. The amplifier features high common-mode rejection ratio (CMRR), low offset voltage, and adjustable gain. Internally, it contains three operational amplifiers that amplify the useful signal using differential amplification while suppressing common-mode interference, ensuring the linearity of the amplified signal. The amplifier's input is electrically connected to the filter's output via internal wiring, receiving the filtered mV-level signal; its output is electrically connected to the A / D converter's input, outputting the amplified V-level signal. The amplifier addresses the issue of weak output signals from the temperature sensing unit by precisely amplifying the signal to reach the optimal input range of the A / D converter, avoiding quantization errors caused by excessively small signals during A / D conversion. Furthermore, the high CMRR further resists external interference, ensuring signal integrity.

[0059] The A / D converter, the final stage module of the signal processing unit, is connected in series between the amplifier and the interface unit. Its core function is to convert the amplified analog signal into a digital signal, facilitating data processing and transmission by the main control communication module. For example, a 16-bit Sigma-Delta A / D converter can be used. This converter achieves high-precision conversion and low noise through sampling and noise shaping techniques. It integrates a reference voltage source and data register, and the conversion rate can be set via main control commands. The analog input of the A / D converter is electrically connected to the output of the amplifier through internal wiring to receive the amplified analog signal; the digital output is electrically connected to the interface unit, transmitting the converted digital signal to the interface unit for subsequent transmission to the main control communication module. Converting continuously changing analog temperature signals into discrete digital signals eliminates the susceptibility to interference and attenuation of analog signals during long-distance transmission. Simultaneously, the 16-bit high precision ensures the resolution of temperature measurement, meeting the high-precision requirements of food temperature measurement.

[0060] In this embodiment, the temperature sensing unit, filter, amplifier, A / D converter, and interface unit form a series signal processing link through the metal wiring inside the digital temperature sensor: the temperature sensing unit converts the food temperature into a raw analog signal → the filter removes noise → the amplifier amplifies the signal → the A / D converter converts the analog signal into a digital signal → the interface unit transmits the digital signal to the shared bus. This step-by-step processing connection ensures that the signal is optimized at each stage, avoiding signal distortion or loss during processing, forming a complete and efficient signal chain.

[0061] Furthermore, in some embodiments, the Bluetooth chip also integrates a multiplexer, the input of which is electrically connected to the shared bus, and the output of which is electrically connected to the main control unit of the Bluetooth chip.

[0062] Specifically, the Bluetooth chip in this embodiment also integrates a multiplexer, manufactured using a CMOS process (compatible with the main Bluetooth chip process, such as 40nm), and centered on digital logic circuits, including an input channel module, a control logic module, and an output module. The multiplexer forms a signal transmission link within the Bluetooth chip: "shared bus - multiplexer - main control unit." As a "smart switch" between the shared bus and the main control unit, its core function is to resolve signal conflicts when multiple sensors share the bus, optimizing data transmission efficiency. When multiple digital temperature sensors transmit signals simultaneously through the shared bus, the multiplexer, through the selection mechanism of the control logic module, allows only the selected sensor signal to be transmitted to the main control unit, isolating other sensor signals and completely avoiding problems such as garbled characters and data loss caused by signal superposition in traditional "non-selective" transmission. The main control unit does not need to process multiple signals simultaneously; instead, it controls the multiplexer to sequentially select each sensor, achieving "time-division processing." For example, when polling eight sensors sequentially, the main control unit can complete the reception and parsing of data from a single sensor within 1ms. The total processing time for all eight sensors is less than 10ms, far lower than the concurrent processing time without a multiplexer, significantly improving real-time performance. The multiplexer implements channel switching through hardware logic, eliminating the need for the main control unit to run complex software arbitration algorithms, thus reducing the main control unit's computational resource consumption and indirectly lowering chip power consumption.

[0063] This embodiment integrates a multiplexer within the Bluetooth chip and constructs a connection link of "shared bus - multiplexer - main control unit". This enhances the communication stability, data processing efficiency, and low power consumption of the non-contact wireless food thermometer used for multi-point temperature measurement in multi-point temperature measurement scenarios, better meeting the actual needs of continuous and accurate temperature measurement of food.

[0064] Furthermore, in some embodiments, the power module includes an energy storage element and a voltage conversion unit, and the output terminal of the energy storage element is electrically connected to the temperature detection module and the main control communication module respectively through the voltage conversion unit; The energy storage element is a lithium-ion supercapacitor. The power module also includes a charge and discharge protection circuit, which is electrically connected to the lithium-ion supercapacitor and is used to provide overcharge protection, over-discharge protection, over-temperature protection, overcurrent protection, and short-circuit protection for the lithium-ion supercapacitor.

[0065] Specifically, the power module in this embodiment includes an energy storage element and a voltage conversion unit. The energy storage element, the core energy storage unit of the power module, is a lithium-ion supercapacitor. Its structure and performance are adapted to the high and low temperature usage scenarios and low power consumption requirements of food thermometers. The positive and negative terminals of the lithium-ion supercapacitor are electrically connected to the input terminal of the charge / discharge protection circuit through circuit board wiring, forming a series link of "energy storage element - protection circuit"; simultaneously, its output terminal is connected to the input terminal of the voltage conversion unit, providing raw power for subsequent voltage conversion. This connection method ensures that the supercapacitor is in a protected state throughout the charging and discharging process, avoiding the risks of overcurrent and overvoltage caused by direct connection to the load or external power supply. The voltage conversion unit is the core of the power module's power regulation, responsible for converting the unstable voltage output by the energy storage element into a stable operating voltage suitable for each functional module, ensuring safe circuit operation. The input of the voltage conversion unit is electrically connected to the output of the charge / discharge protection circuit via circuit board wiring, and can also be selectively connected to an external charging power supply. Its output is connected to the power pins of the temperature detection module (3.3V), main control communication module (3.0V), etc., via multiple power lines to provide a stable voltage. A 0.1μF ceramic capacitor is connected in series in the circuit to filter out high-frequency ripple generated during voltage conversion, preventing interference with sensitive circuits.

[0066] In addition, the power module in this embodiment also includes a charge / discharge protection circuit, which is the core of safety protection for the energy storage element. By monitoring the working status of the supercapacitor in real time, it triggers the corresponding protection mechanism to prevent damage caused by abnormal operating conditions. The charge / discharge protection circuit is connected in series with the lithium-ion supercapacitor in the power supply link. Its input terminal is connected to the positive and negative terminals of the supercapacitor, and its output terminal is connected to the voltage conversion unit. At the same time, the detection pins of the protection IC are connected to the supercapacitor, the sampling resistor, and the NTC thermistor through wiring. The series design ensures that the protection circuit can intercept abnormal current / voltage in real time and directly cut off the dangerous path. The various parts of the power module form a complete link of "external charging power supply → charge / discharge protection circuit → lithium-ion supercapacitor → charge / discharge protection circuit → voltage conversion unit → load module (temperature detection module, main control communication module)": when the external power supply is connected, the supercapacitor is charged through the protection circuit, and the load is powered through the voltage conversion unit; when the external power supply is disconnected, the supercapacitor powers the load through the protection circuit and the voltage conversion unit. The entire process is monitored by the charge / discharge protection circuit to ensure the safety and stability of each link.

[0067] This embodiment improves the device's endurance and durability by leveraging the high energy density and long cycle life of lithium-ion supercapacitors. Their wide temperature range adapts to the complex environment of food temperature measurement. The voltage conversion unit ensures that each module receives a stable operating voltage, reducing temperature measurement errors caused by voltage fluctuations. The charge and discharge protection circuit provides multi-dimensional protection to prevent damage to the energy storage components from abnormal operating conditions such as overcharging, over-discharging, and over-temperature.

[0068] Furthermore, in some embodiments, the voltage conversion unit is an LDO regulator or a DC-DC converter, the input terminal of the voltage conversion unit is electrically connected to an external charging power supply or the energy storage element, and the output terminal of the voltage conversion unit outputs a working voltage adapted to the temperature detection module and the main control communication module.

[0069] Specifically, the voltage conversion unit in this embodiment can be an LDO regulator or a DC-DC converter. An LDO (Low Dropout Linear Regulator) is one implementation of a voltage conversion unit, suitable for low-power, low-noise scenarios. Its core function is to linearly step down an unstable input voltage to a stable output voltage with a very small voltage drop (the difference between the input and output voltages). The LDO's input terminal (VIN) is electrically connected to an external charging power supply or energy storage element via circuit board wiring to receive the original supply voltage. The output terminal (VOUT) is connected to the power pins of the temperature detection module and the main control communication module via multiple power lines to provide a stable operating voltage. The ground terminal (GND) is connected to the circuit board ground, forming a loop. Furthermore, the LDO's enable pin is connected to the input terminal. When the external charging power supply is disconnected and the device enters sleep mode, the standby power consumption drops to <1μA. LDO regulators utilize the linear buck principle, resulting in extremely low output voltage ripple. This avoids high-frequency noise interference with the signal processing unit of the temperature sensor, ensuring temperature measurement accuracy. Their low dropout characteristics allow for a stable output of 3.0V even when the energy storage element voltage is low, extending the device's battery life. Furthermore, they eliminate the need for inductors or other magnetic components, reducing electromagnetic interference and meeting the anti-interference requirements of wireless communication modules.

[0070] The DC-DC converter is another implementation of a voltage conversion unit, employing a switching regulation principle. It is suitable for medium-to-high power consumption and high-efficiency scenarios, achieving voltage conversion through inductor energy storage and capacitor filtering. The input terminal (VIN) of the DC-DC converter also connects to an external charging power supply or energy storage element, compatible with a wide input voltage range (3.0-5.5V). The output terminal (VOUT) connects to various functional modules via power lines, and the output voltage can be configured via feedback network resistors (e.g., 3.3V or 3.0V). External components such as inductors and capacitors are soldered close to the chip, shortening wiring length and reducing switching noise. Similar to an LDO, its enable terminal can be controlled by the main control module, turning off in non-operating states to reduce power consumption. By significantly reducing energy loss through the switching regulation principle, it can reduce power consumption and extend the operating time of energy storage elements compared to an LDO in high-load scenarios (such as Bluetooth high-frequency communication and simultaneous sampling by multiple sensors). Its wide input voltage range adapts to different external power supplies, improving device compatibility. Its high current output capability meets the power supply needs of multiple modules operating simultaneously.

[0071] This embodiment utilizes the low-noise characteristics of LDO to ensure the high-precision temperature measurement requirements of the temperature sensor, and the high-efficiency characteristics of DC-DC to improve energy utilization in high-load scenarios. Both are adapted to different power consumption scenarios, enhancing the flexibility of the power supply solution. The input side is compatible with external power supplies and energy storage components, and the output side accurately matches the voltage of each module, ensuring power supply stability and safety. Intelligent switch control further reduces standby power consumption.

[0072] Furthermore, in some embodiments, the ESD protection structure includes a protection diode disposed at the power input terminal and the signal input / output terminal, and the protection diode is disposed close to the ports of the power input terminal and the signal input / output terminal.

[0073] Specifically, the core of the ESD protection structure is the protection diode, specifically a transient voltage suppressor diode (TVS diode). Its design is adapted to the low-voltage operating environment (3-5V) and rapid electrostatic response requirements of food thermometers. The TVS diode utilizes the avalanche breakdown principle of a semiconductor PN junction, forming a highly doped PN junction from P-type and N-type semiconductors, packaged in a surface-mount structure, providing bidirectional protection. Its key parameters include: a breakdown voltage (VBR) slightly higher than the device's operating voltage to ensure a high-resistivity state during normal operation; a clamping voltage (VC) lower than the withstand voltage of the protected component; and a response time <1ns for rapid absorption of electrostatic pulses.

[0074] Protection diodes are installed strictly according to the "proximity protection" principle, deployed at both the power input and signal input / output terminals. A TVS diode is connected in parallel between the power input terminal (such as the VCC pin of the external charging interface) and ground (GND). The anode of the diode is connected to GND, and the cathode is connected to the power input line, connected by a 0.2mm wide thick copper foil trace to reduce parasitic inductance. When static electricity is introduced during external charging, causing a voltage surge, the diode breaks down instantly, clamping the overvoltage to a safe value and preventing high voltage from entering the voltage conversion unit (LDO / DC-DC) and energy storage components (lithium-ion supercapacitors), thus avoiding damage due to overvoltage. The signal input / output terminals include signal pins of the shared bus (IIC / single bus), Bluetooth antenna interface, etc., with a TVS diode connected in parallel between each signal pin and GND. Taking the SDA line of the shared bus as an example, the diode anode is connected to GND, and the cathode is connected to the SDA line, with a trace length of <5mm, and crossing with other signal lines is avoided. When electrostatic interference occurs on the signal line, the diode quickly conducts, discharging the transient high voltage on the signal line to ground, ensuring that the signal voltage transmitted to the digital temperature sensor or main control communication module is always within a safe range, preventing signal distortion or damage to the chip interface.

[0075] This embodiment achieves targeted electrostatic discharge (ESD) protection by placing protection diodes close to the power input and signal input / output terminals. The fast response characteristics and precise clamping capabilities of TVS diodes can effectively absorb transient high voltages generated by ESD / EOS, preventing damage to the power module, sensors, and main control chip. The layout design close to the port minimizes energy loss along the ESD propagation path, ensuring protection efficiency. Combined with designs such as thick wiring, a complete discharge link from the port to ground is formed.

[0076] Furthermore, in some embodiments, the circuit board is a four-layer PCB board, the PCB board is provided with a ground line, and the edge of the PCB board is provided with a metal edging, the metal edging being electrically connected to the ground line.

[0077] Specifically, the circuit board adopts a four-layer PCB (printed circuit board), and through a specific layer stacking order and wiring plan, it constructs an efficient signal transmission, power supply and grounding network to meet the equipment's requirements for high-precision temperature measurement and low power consumption.

[0078] The four-layer PCB board consists of “signal layer 1-ground layer-power layer-signal layer 2” from top to bottom. The layers are bonded together with a glass fiber epoxy resin substrate (FR4), with a total thickness of 1.6mm (industry standard thickness).

[0079] Signal Layer 1 (Top Layer): This layer mainly houses the digital temperature sensor of the temperature detection module, the signal lines of the shared bus (IIC / single bus), etc. It uses a line width of 0.2-0.3mm. When routing, avoid parallel routing with high-frequency signals (such as Bluetooth antenna feed lines) to reduce crosstalk. Grounding layer (intermediate layer): A complete large-area copper foil grounding layer (coverage ≥90%), 35μm thick, serving as the reference ground for the entire circuit and providing a low-impedance (<10mΩ) grounding reference; Power layer (intermediate layer): Adjacent to the ground layer, it is also a large area copper foil used to transmit the stable voltage output of the power module (such as 3.3V, 3.0V). It is connected to the power pins of the top / bottom layers through multiple vias to reduce the power network impedance. Signal Layer 2 (bottom layer): This layer mainly houses the main control communication module (Bluetooth chip), power module charging and discharging protection circuits, etc. It is connected to the top signal layer through vias to avoid delays caused by excessively long signal lines.

[0080] The grounding system, centered on the grounding layer and incorporating surface copper plating and multi-point grounding design, forms a globally low-impedance grounding network, providing a path for electrostatic discharge and noise suppression. The grounding layer, acting as the main grounding line, is connected to the top and bottom surface grounding lines via dense vias (spacing ≤10mm). These surface grounding lines form "grounding islands" around various functional modules (such as sensors and Bluetooth chips), and then connect to the grounding layer via vias, achieving a hierarchical structure of "local grounding - global grounding."

[0081] The metal edging is arranged along the edge of the PCB board and electrically connected to the ground wire, forming a dual function of physical protection and electrostatic shielding. The metal edging is connected to the ground layer through an extension of the surface ground wire (0.5mm wide copper foil), with each connection point corresponding to a grounding via, creating a low-impedance path (impedance <50mΩ) between the edging and the ground layer. This design makes the metal edging an "extension" of the ground layer, expanding the grounding area. When the device casing comes into contact with the metal edging, static electricity on the casing (such as static electricity generated by user touch) can be conducted to the ground wire through the edging, preventing static electricity from directly entering the internal circuitry; at the same time, the metal edging forms a surrounding shield for the PCB board, weakening the impact of external high-frequency electromagnetic interference on internal signal lines and improving the stability of wireless communication.

[0082] This embodiment reduces signal interference and power impedance through the independent grounding and power layers of the four-layer board, ensuring the integrity of temperature and communication signals; the large-area ground wire and multi-point grounding design shorten the electrostatic discharge path, reduce grounding impedance, and improve ESD resistance; the metal edging, as an extension of the ground wire, expands the grounding area and enhances electromagnetic shielding, further resisting external interference.

[0083] Furthermore, in some embodiments, the non-contact wireless food thermometer for multi-point temperature measurement also includes a housing, the housing being made of a conductive material or having a conductive coating on its surface, and the housing being electrically connected to the ground wire of the PCB board.

[0084] Specifically, the outer casing, serving as the outer protective structure of the equipment, balances food contact safety with electrostatic discharge protection. The conductive casing is made of food-grade conductive metal alloy or conductive plastic. Metal alloy casings possess excellent conductivity and mechanical strength, allowing direct contact with high-temperature food; conductive plastic casings achieve conductivity through material modification while maintaining lightweight and corrosion resistance, making them suitable for humid environments. For non-conductive substrates, a conductive coating is applied to the casing surface. The coating material is selected from conductive silver paste, graphene paste, or nickel-based conductive coatings, with a thickness of 5-10 μm, forming a continuous conductive film after curing. The coating has strong adhesion to the substrate and has passed food contact safety certification, ensuring no harmful substances are released during food contact.

[0085] The outer casing forms a reliable electrical connection with the ground wire of the PCB board through a dedicated conductive connector, constructing an electrostatic discharge path of "outer casing-grounding system". The electrostatic charge on the outer casing is transferred to the metal edge of the PCB board through the conductive connector, and then introduced into the ground layer of the PCB board through the connection point between the metal edge and the surface ground wire, finally forming a low-impedance discharge path of "outer casing → conductive connector → metal edge → ground layer" to meet the requirements of rapid electrostatic discharge.

[0086] This embodiment utilizes the conductive properties of the outer casing to make it the primary discharge channel for electrostatic charges. Combined with the low-impedance connection to the grounding system, it significantly reduces the risk of electrostatic intrusion into the internal circuitry. The Faraday cage shielding effectively resists internal and external electromagnetic interference, ensuring the stability of temperature data transmission and wireless communication. At the same time, the structural protection capabilities of the outer casing extend the service life of the equipment.

[0087] In specific embodiments, such as Figure 2 As shown, Figure 2 The circuit diagram of the non-contact wireless food thermometer for multi-point temperature measurement provided in this embodiment includes a Bluetooth chip, a digital temperature sensor, a thermistor, a low dropout linear regulator, a battery, a charging management IC, a charging pin, an antenna, and an oscillator. BT-IC (Bluetooth chip): Integrates Bluetooth communication, main control computing, and data processing functions. It is responsible for receiving temperature data, running algorithms, and communicating with mobile phones / cloud. DTS*5 (Digital Temperature Sensors × 5): 5 sets of digital temperature sensors based on the BJT (Bipolar Junction Transistor) principle, used to collect the temperature at different points on the food. NTC*1 (Negative Temperature Coefficient Thermistor ×1): 1 set of NTC thermistors, usually used to monitor the temperature of the device itself (such as battery, chip) and assist in temperature compensation. LDO (Low Dropout Linear Regulator): Linearly steps down and regulates the input voltage to provide a stable, low-noise power supply for the system; BAT-3.8V (3.8V battery / supercapacitor): Energy storage element that powers the system; ChargeIC (Charging Management IC): Manages the charging process and provides overcharge, over-discharge, and overcurrent protection; Chargepin: External power input terminal (such as USB charging port); Antenna: Used for Bluetooth signal transmission and reception, enabling wireless data transmission; OSC32MHz (32MHz oscillator): Provides a high-frequency clock signal for the Bluetooth chip, ensuring communication and operation timing.

[0088] The charging link consists of an external power supply via Chargepin → ChargeIC → charging BAT-3.8V, with ChargeIC controlling the charging process.

[0089] The discharge power supply link consists of BAT-3.8V → LDO voltage regulation → powering BT-IC, DTS5, NTC1, etc.

[0090] The signal acquisition link uses DTS5 (5 sets of digital temperature sensors) and NTC1 (1 set of NTC thermistors) to acquire temperature, and the digital signal is transmitted to BT-IC.

[0091] The communication and clock link uses OSC32MHz to provide a clock to the BT-IC, which then uses Antenna to implement Bluetooth wireless communication and transmit temperature data to the outside world.

[0092] Five sets of digital temperature sensors enable multi-point temperature measurement of food, covering different probe depths and positions. The Bluetooth chip collects data through a time-division / polling mechanism, solving the problem of limited temperature measurement by a single sensor. A charging management IC ensures safe charging and discharging of the battery, while a low-dropout linear regulator filters power supply noise, providing a clean power supply to the temperature sensors and preventing voltage fluctuations from affecting measurement accuracy. A 32MHz oscillator provides a high-frequency clock for the Bluetooth chip, ensuring Bluetooth communication speed (such as BLE 5.0 protocol) and data processing efficiency. Optimized antenna design (such as PCB antenna and ceramic antenna) improves wireless transmission distance and stability.

[0093] In summary, this embodiment provides a non-contact wireless food thermometer for multi-point temperature measurement. The temperature detection module employs a digital temperature sensor based on the bipolar transistor principle, featuring small size, good linearity, high accuracy, and low power consumption, enabling accurate acquisition of food temperatures at multiple points. The temperature detection module and the main control communication module are connected via a shared bus, reducing the interface occupancy and wiring complexity of the main control communication module, effectively solving the problem of requiring more I / O resources for multi-point temperature measurement, and ensuring efficient transmission of temperature information. The main control communication module is responsible for receiving temperature information and implementing wireless communication, ensuring stable data transmission. A power supply module provides stable power support to all modules. Furthermore, ESD protection structures are installed at the power supply and signal input / output terminals, effectively resisting electrostatic discharge and overstress damage. Therefore, this embodiment can achieve effective acquisition and wireless transmission of food temperature, while improving the device's anti-static capability and power supply stability, effectively solving the problems of insufficient temperature detection accuracy and stability in existing technologies.

[0094] That is, the above description is only an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, such as the combination of technical features between different embodiments, or direct or indirect application in other related technical fields, are similarly included within the patent protection scope of this application.

[0095] Furthermore, for structural elements with the same or similar characteristics, this application may use the same or different reference numerals for identification. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0096] In this application, the word "for example" is used to mean "used as an example, illustration, or explanation." Any embodiment described as "for example" in this application is not necessarily to be construed as more preferred or advantageous than other embodiments. This application has been provided above to enable any person skilled in the art to make and use it. Various details are set forth in the above description for purposes of explanation.

[0097] It should be understood that those skilled in the art will recognize that this application can be implemented without using these specific details. In other embodiments, well-known structures and processes will not be described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

Claims

1. A non-contact wireless food thermometer for multi-point temperature measurement, characterized by, Includes a housing and a circuit board disposed within the housing, the circuit board comprising: The temperature detection module includes at least one digital temperature sensor based on the bipolar transistor principle, used to collect temperature information of the food. The main control communication module is electrically connected to the temperature detection module via a shared bus, and is used to receive temperature information collected by the temperature detection module and perform wireless communication. The power supply module is electrically connected to the temperature detection module and the main control communication module respectively, and is used to provide working power to the temperature detection module and the main control communication module; ESD protection structure, wherein the ESD protection structure is disposed at the power input terminal and signal input / output terminal of the non-contact wireless food thermometer for multi-point temperature measurement; The digital temperature sensor integrates a temperature sensing unit, a signal processing unit, and an interface unit. The interface unit is connected to the shared bus. Multiple digital temperature sensors are connected in parallel through the shared bus, and all are electrically connected to the same bus interface of the main control communication module.

2. The non-contact wireless food thermometer for multi-point temperature measurement according to claim 1, wherein, The main control communication module is a Bluetooth chip. The Bluetooth chip is connected to the digital temperature sensor via the shared bus. Multiple digital temperature sensors are electrically connected to the same bus interface of the Bluetooth chip. The Bluetooth chip is a BLE protocol Bluetooth chip that integrates a main control unit, an ADC unit, a storage unit, and an internal temperature measurement unit. The input terminal of the ADC unit is electrically connected to the output terminal of the power module. The storage unit is a Flash memory or an OTP memory. The internal temperature measurement unit is electrically connected to the main control unit of the Bluetooth chip.

3. The non-contact wireless food thermometer for multi-point temperature measurement according to claim 1, wherein, The shared bus is an IIC bus or a single bus, and the interface unit of the digital temperature sensor is an IIC interface adapted to the IIC bus, or a single bus interface adapted to the single bus.

4. The non-contact wireless food thermometer for multi-point temperature measurement according to claim 1, wherein, The signal processing unit includes a filter, an amplifier, and an A / D converter. The output terminal of the temperature sensing unit is electrically connected to the input terminal of the A / D converter in sequence through the filter and the amplifier. The output terminal of the A / D converter is electrically connected to the interface unit.

5. The non-contact wireless food thermometer for multi-point temperature measurement according to claim 1, wherein, The power module includes an energy storage element and a voltage conversion unit. The output terminal of the energy storage element is electrically connected to the temperature detection module and the main control communication module through the voltage conversion unit. The energy storage element is a lithium-ion supercapacitor. The power module also includes a charge and discharge protection circuit, which is electrically connected to the lithium-ion supercapacitor and is used to provide overcharge protection, over-discharge protection, over-temperature protection, overcurrent protection, and short-circuit protection for the lithium-ion supercapacitor.

6. The non-contact wireless food thermometer for multi-point temperature measurement according to claim 5, wherein, The voltage conversion unit is an LDO regulator or a DC-DC converter. The input terminal of the voltage conversion unit is electrically connected to an external charging power supply or the energy storage element. The output terminal of the voltage conversion unit outputs a working voltage adapted to the temperature detection module and the main control communication module.

7. The non-contact wireless food thermometer for multi-point temperature measurement according to claim 1, wherein, The ESD protection structure comprises a protection diode, which is arranged at the power input end and the signal input / output end, and is arranged close to the ports of the power input end and the signal input / output end.

8. The non-contact wireless food thermometer for multi-point temperature measurement according to claim 1, wherein, The circuit board is a four-layer PCB board, a ground wire is arranged on the PCB board, and a metal edge cover is arranged at the edge of the PCB board and electrically connected with the ground wire.

9. The non-contact wireless food thermometer for multi-point temperature measurement according to claim 8, wherein, The non-contact wireless food thermometer for multi-point temperature measurement further comprises a shell made of a conductive material or provided with a conductive coating, and the shell is electrically connected with the ground wire of the PCB board.

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