Circuit system for multiplexing LED (light-emitting diode) segment driving and power-down memory functions and control method of circuit system

Abstract

The invention relates to the field of LED segment driving, in particular to an LED segment driving and power failure memory function multiplexing circuit system and a control method thereof, and the LED segment driving and power failure memory function multiplexing circuit system comprises a power supply module, an LED segment driving module, a power failure detection module, a data storage module and a control module, the LED segment driving function and the power-down memory function are integrated in one circuit system, and the memory in the control module is used for storing display data, so that the power-down memory function without an additional nonvolatile memory is realized. The circuit system has the advantages of low cost, low complexity, high integration level, good reliability and the like, and can be widely applied to various electronic devices which have LED display and need a power-down memory function. Experimental verification results show that the circuit system and the control method thereof can effectively realize LED segment driving and power failure memory functions, and meet the requirements of practical application.

Description

[0001] In the field of technology The present invention belongs to the field of LED segment driving, and in particular relates to a circuit system for multiplexing LED segment driving and power-off memory functions and a control method thereof. Background Art

[0002] As an energy-efficient, solid-state light source, LEDs (light-emitting diodes) have gained widespread application in lighting and display applications due to their exceptionally long lifespan, absence of harmful substances, eye-friendly properties, high luminous efficacy, and low heat generation. In many electronic devices, LED segment displays are widely used to display information such as numbers and characters, providing intuitive user interfaces.

[0003] However, existing LED segment driver circuits typically only have the function of driving LED displays, and their functions are relatively simple. In some application scenarios, electronic devices need to have a power-off memory function, that is, when the device is powered on again after a power outage, it is possible to restore to the state before the power outage. For example, when an electronic clock is powered on again after a power outage, it is hoped that the time set before the power outage will be displayed; when an electronic instrument is powered on again after a power outage, it is hoped that the measurement data before the power outage will be displayed. Currently, implementing a power-off memory function usually requires additional storage circuits, such as non-volatile memories such as EEPROM and FRAM. This not only increases the cost and complexity of the circuit, but also takes up valuable circuit board space.

[0004] Furthermore, existing LED segment driver circuits often suffer from insufficient driving capability and uneven display brightness when driving multiple LED segments, affecting the clarity and stability of the LED display. Therefore, developing a circuit system and control method that integrates LED segment driving with power-off memory functionality is of great practical significance. Summary of the Invention

[0005] In response to the above-mentioned situation, the present invention provides a circuit system and a control method thereof that multiplexes LED segment driving and power-off memory functions. When an electronic clock is powered on again after a power outage, it is hoped that the time set before the power outage will be displayed; when an electronic instrument is powered on again after a power outage, it is hoped that the measurement data before the power outage will be displayed. At present, the realization of the power-off memory function usually requires additional storage circuits, such as non-volatile memories such as EEPROM and FRAM, which not only increases the cost and complexity of the circuit, but also takes up valuable circuit board space. In addition, when driving multiple LED segments, the existing LED segment driving circuit often has problems such as insufficient driving capability and uneven display brightness, which affects the clarity and stability of the LED display. The system includes a power supply module, an LED segment driving module, a power-off detection module, a data storage module, and a control module: Power supply module: This module provides stable power to the entire circuit system. It can include AC-DC conversion circuitry or DC-DC conversion circuitry, depending on the type of input power. LED segment driver module: used to drive the LED segment display. The LED segment driver module can adopt constant current drive or constant voltage drive mode to ensure stable display of the LED segment; Power failure detection module: used to detect power failure of the power supply. The power failure detection module may include a voltage comparator and a reference voltage source; Data storage module: used to store the display data of the LED segment to achieve power-off memory function. The data storage module can be implemented using registers or memory inside the control module, without the need for additional non-volatile memory; Control module: As the core of the entire circuit system, it is responsible for controlling the driving operation of the LED segment driver module, receiving the power-off signal from the power-off detection module, and managing the data storage and reading of the data storage module.

[0006] Furthermore, when the input is AC power, the power module converts the AC power into stable DC power through rectification, filtering and voltage stabilization; when the input is DC power, the power module can perform voltage conversion and voltage stabilization as needed.

[0007] Furthermore, the LED segment driver module employs a constant current drive circuit, ensuring stable LED operation by limiting the current. A current source (such as a resistor, current module, or current driver chip) is used to provide a constant current and is connected to the LED segment. When the voltage fluctuates, the current source automatically adjusts to maintain a constant current output.

[0008] Furthermore, the power-off detection module compares the power supply voltage with a reference voltage, and when the power supply voltage is lower than the reference voltage, determines that a power-off situation has occurred, and sends a power-off signal to the control module.

[0009] Furthermore, the data storage module can be implemented using registers or memory within the control module, without requiring additional non-volatile memory. For example, the control module can use a microcontroller with a large storage capacity to store the display data of the LED segments in its internal Flash memory.

[0010] Furthermore, the control module may be a microcontroller (MCU), such as the Saiyuan SC92F8413B single chip microcomputer.

[0011] Furthermore, the circuit control method is characterized by comprising the following steps: 1. Initialization phase After powering on, the control module performs initialization operations, including setting the initial state of the LED segment driver module and initializing the data storage module. For example, the control module sets the output of the LED segment driver module to the initial display state, such as all off or displaying a specific pattern. Simultaneously, the control module checks whether valid display data is stored in the data storage module. If so, it reads the data and prepares it for subsequent display control.

[0012] 2. Normal display stage The control module generates the corresponding LED segment display data based on preset display rules or external input signals, and sends this data to the LED segment driver module, which drives the LED segments to display the corresponding information. For example, in an electronic clock application, the control module generates corresponding digital display data based on the time information of the internal clock circuit, and drives the LED segments to display the current time.

[0013] At the same time, the control module regularly stores the current LED segment display data in the data storage module to achieve power-off memory function. The storage cycle can be set according to actual needs, for example, storing display data once every minute.

[0014] 3. Power-off detection stage The power-off detection module monitors the power supply voltage in real time. When it detects that the power supply voltage is lower than the reference voltage, it determines that a power-off situation has occurred and sends a power-off signal to the control module.

[0015] 4. Power-off processing stage Upon receiving the power-off signal, the control module immediately stops the current display operation and urgently stores the current LED segment display data in the data storage module to ensure data integrity and accuracy. For example, the control module can prioritize storing display data in a specific area of ​​the internal memory and set a corresponding flag to distinguish between normal storage and power-off emergency storage data.

[0016] At the same time, the control module enters low power mode to reduce power consumption when power is off and extend battery life (if battery-powered).

[0017] 5. Power-on recovery phase When the power is turned on again, the control module wakes up from the low power mode and first reads the LED segment display data stored in the data storage module before the power failure.

[0018] The control module restores the LED segment display status based on the read display data, restoring the device to its pre-power-off state. For example, an electronic clock can display the time set before power failure after power is restored; an electronic instrument can display the measurement data before power failure after power is restored.

[0019] In the technical solution provided by the present invention, by reducing cost and complexity: the circuit system of the present invention does not require additional non-volatile memory to implement the power-off memory function, and uses the register or memory inside the control module to store display data, thereby reducing circuit cost and complexity and reducing the space occupied by the circuit board.

[0020] Improve integration and reliability: Integrating the LED segment driving function and power-off memory function into one circuit system improves the circuit integration, reduces the connection and interference between circuit components, and thus improves the circuit reliability.

[0021] Enhanced user experience: The device can be restored to its pre-power-off state when powered on again after a power outage, providing users with a more convenient and continuous usage experience. It is especially suitable for application scenarios with high requirements for data continuity.

[0022] Strong flexibility and scalability: The control method of the present invention can be flexibly adjusted and expanded according to different application requirements, such as modifying display rules, adjusting storage cycles, etc., to meet the personalized needs of different electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Various other advantages and benefits will become apparent to those skilled in the art by reading the following detailed description of the preferred embodiment.The accompanying drawings are only for the purpose of illustrating the preferred embodiment and are not to be considered as limiting the present invention.

[0024] Figure 1 Schematic diagram of a first embodiment of a circuit system for multiplexing LED segment driving and power-off memory functions in an embodiment of the present invention.

[0025] Figure 2 Schematic diagram of a second embodiment of a circuit control method for multiplexing LED segment driving and power-off memory functions in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0028] A circuit system that multiplexes LED segment drive and power-off memory functions, such as Figure 1 As shown, it includes power module, LED segment driver module, power failure detection module, data storage module and control module: Power supply module: This module provides stable power to the entire circuit system. It can include AC-DC conversion circuitry or DC-DC conversion circuitry, depending on the type of input power. LED segment driver module: used to drive the LED segment display. The LED segment driver module can adopt constant current drive or constant voltage drive mode to ensure stable display of the LED segment; Power failure detection module: used to detect power failure of the power supply. The power failure detection module may include a voltage comparator and a reference voltage source; Data storage module: used to store the display data of the LED segment to achieve power-off memory function. The data storage module can be implemented using registers or memory inside the control module, without the need for additional non-volatile memory; Control module: As the core of the entire circuit system, it is responsible for controlling the driving operation of the LED segment driver module, receiving the power-off signal from the power-off detection module, and managing the data storage and reading of the data storage module.

[0029] In this embodiment, when the input is AC power, the power module converts the AC power into stable DC power through rectification, filtering and voltage stabilization; when the input is DC power, the power module can perform voltage conversion and voltage stabilization as needed.

[0030] Specifically, the present invention uses a power supply module: an AC-DC conversion circuit is used to reduce the voltage of 220V AC power through a transformer, rectify it through a rectifier bridge, filter it with a capacitor, and stabilize it with a voltage regulator chip, and then output a stable 5V DC power to power the entire circuit system.

[0031] In this embodiment, the LED segment driver module employs a constant current drive circuit to ensure stable LED operation by limiting the current. A current source (such as a resistor, current module, or current driver chip) is used to provide a constant current and is connected to the LED segments. When the voltage fluctuates, the current source automatically adjusts to maintain a constant current output.

[0032] Specifically, the LED segment driver module uses a constant-current drive method, employing a 74HC595 shift register and a ULN2003 Darlington array to drive common-cathode LED digital tubes. The 74HC595 receives serial data from the control module and converts it into parallel data for output; the ULN2003 amplifies the drive current to drive the LED digital tubes to emit light.

[0033] In this embodiment, the power-off detection module compares the power supply voltage with a reference voltage, and when the power supply voltage is lower than the reference voltage, determines that a power-off situation has occurred, and sends a power-off signal to the control module.

[0034] Specifically, the power-off detection module uses an LM393 voltage comparator to compare the power supply voltage with a reference voltage provided by a Zener diode. When the power supply voltage falls below the reference voltage, the LM393 outputs a low-level signal, which is sent to the control module as a power-off signal.

[0035] In this embodiment, the data storage module can be implemented using registers or memory within the control module, without requiring additional non-volatile memory. For example, the control module can use a microcontroller with a large storage capacity to store the display data of the LED segments in its internal Flash memory.

[0036] Specifically, the data storage module uses the Flash memory inside the 51 series microcontroller to store the display data of the LED segments. Flash memory is non-volatile and can retain data after power failure.

[0037] In this embodiment, the control module may be a microcontroller (MCU), such as the Saiyuan SC92F8413B single-chip microcomputer.

[0038] Specifically, the control module uses the Saiyuan SC92F8413B microcontroller as the control core, which is responsible for controlling the driving operation of the LED segment driver module, receiving the power-off signal of the power-off detection module, and managing the data storage and reading of the data storage module.

[0039] In this embodiment, the circuit control method is as follows: Figure 2 As shown, it is characterized in that it includes the following steps: 1. Initialization phase After powering on, the control module performs initialization operations, including setting the initial state of the LED segment driver module and initializing the data storage module. For example, the control module sets the output of the LED segment driver module to the initial display state, such as all off or displaying a specific pattern. Simultaneously, the control module checks whether valid display data is stored in the data storage module. If so, it reads the data and prepares it for subsequent display control.

[0040] 2. Normal display stage The control module generates the corresponding LED segment display data based on preset display rules or external input signals, and sends this data to the LED segment driver module, which drives the LED segments to display the corresponding information. For example, in an electronic clock application, the control module generates corresponding digital display data based on the time information of the internal clock circuit, and drives the LED segments to display the current time.

[0041] At the same time, the control module regularly stores the current LED segment display data in the data storage module to achieve power-off memory function. The storage cycle can be set according to actual needs, for example, storing display data once every minute.

[0042] 3. Power-off detection stage The power-off detection module monitors the power supply voltage in real time. When it detects that the power supply voltage is lower than the reference voltage, it determines that a power-off situation has occurred and sends a power-off signal to the control module.

[0043] 4. Power-off processing stage Upon receiving the power-off signal, the control module immediately stops the current display operation and urgently stores the current LED segment display data in the data storage module to ensure data integrity and accuracy. For example, the control module can prioritize storing display data in a specific area of ​​the internal memory and set a corresponding flag to distinguish between normal storage and power-off emergency storage data.

[0044] At the same time, the control module enters low power mode to reduce power consumption when power is off and extend battery life (if battery-powered).

[0045] 5. Power-on recovery phase When the power is turned on again, the control module wakes up from the low power mode and first reads the LED segment display data stored in the data storage module before the power failure.

[0046] The control module restores the LED segment display status based on the read display data, restoring the device to its pre-power-off state. For example, an electronic clock can display the time set before power failure after power is restored; an electronic instrument can display the measurement data before power failure after power is restored.

[0047] Specifically, the initialization phase After the Saiyuan SC92F8413B microcontroller is powered on, it performs initialization operations, including setting serial port communication parameters, initializing the timer, initializing the 74HC595 shift register, etc.

[0048] Check whether valid display data is stored in the Flash memory. If so, read the data and prepare it for subsequent display control. If not, set the initial display time to 00:00:00.

[0049] Normal display stage The Saiyuan SC92F8413B microcontroller obtains the current time information through the internal timer and generates the corresponding LED segment display data based on the time information.

[0050] The display data is sent to the 74HC595 shift register via serial communication, driving the LED digital tube to display the current time.

[0051] Every 1 minute, the current display data is stored in the Flash memory to achieve power-off memory function.

[0052] Power-off detection phase The LM393 voltage comparator monitors the power supply voltage in real time. When it detects that the power supply voltage is lower than the reference voltage, it outputs a low-level power-off signal and sends it to the external interrupt pin of the Saiyuan SC92F8413B microcontroller.

[0053] Power-off processing stage After receiving the power-off signal, the Saiyuan SC92F8413B microcontroller immediately enters the external interrupt service routine, stops the current display operation, and urgently stores the current display data in a specific area of ​​the Flash memory, and sets the corresponding flag bit to distinguish between normal storage and power-off emergency storage data.

[0054] At the same time, the Saiyuan SC92F8413B microcontroller enters low-power mode, shuts down unnecessary peripherals and clocks, and reduces power consumption during power failure.

[0055] Power-on recovery phase When the power is turned on again, the Saiyuan SC92F8413B microcontroller wakes up from the low power mode and first reads the display data and flag bits stored in the Flash memory before power failure.

[0056] If the flag indicates that the data is stored for emergency during power failure, the display state of the LED digital tube is restored according to the data, and the electronic clock is restored to the time before the power failure; if the flag indicates that the data is stored normally, the display is performed according to the normal process.

[0057] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A circuit system for multiplexing LED segment drive and power-off memory functions and a control method thereof, characterized in that: The circuit system with multiplexing LED segment driving and power-off memory functions includes a power supply module, an LED segment driving module, a power-off detection module, a data storage module, and a control module: Power supply module: This module provides stable power to the entire circuit system. It can include AC-DC conversion circuitry or DC-DC conversion circuitry, depending on the type of input power. LED segment driver module: used to drive the LED segment display. The LED segment driver module can adopt constant current drive or constant voltage drive mode to ensure stable display of the LED segment; Power failure detection module: used to detect power failure of the power supply. The power failure detection module may include a voltage comparator and a reference voltage source; Data storage module: used to store the display data of the LED segment to realize the power-off memory function. The data storage module can be realized by using the register or memory inside the control module without the need for additional non-volatile memory; Control module: As the core of the entire circuit system, it is responsible for controlling the driving operation of the LED segment driver module, receiving the power-off signal from the power-off detection module, and managing the data storage and reading of the data storage module.

2. A circuit system for multiplexing LED segment driving and power-off memory functions according to claim 1, characterized in that: When the power supply module receives AC power, it converts the AC power into stable DC power through rectification, filtering and voltage stabilization. When the power supply module receives DC power, it can perform voltage conversion and voltage stabilization as needed.

3. The circuit system for multiplexing LED segment driving and power-off memory functions according to claim 1, characterized in that: The LED segment driver module adopts a constant current drive circuit to ensure the stable operation of the LED by limiting the current size. A current source is used to provide a constant current and is connected to the LED segment. When the voltage fluctuates, the current source automatically adjusts to maintain a constant current output.

4. The circuit system for multiplexing LED segment driving and power-off memory functions according to claim 1, characterized in that: The power-off detection module compares the power supply voltage with a reference voltage, and when the power supply voltage is lower than the reference voltage, determines that a power-off situation has occurred, and sends a power-off signal to the control module.

5. The circuit system for multiplexing LED segment driving and power-off memory functions according to claim 1, characterized in that: The data storage module can be implemented by using registers or memories inside the control module without the need for additional non-volatile memory. The control module uses a microcontroller with a large storage capacity to store the display data of the LED segment in the internal Flash memory.

6. The circuit system for multiplexing LED segment driving and power-off memory functions according to claim 1, characterized in that: The control module adopts a microcontroller (MCU), and the optional Saiyuan SC92F8413B microcontroller.

7. The circuit control method for multiplexing LED segment driving and power-off memory functions according to claim 1, characterized in that: The following steps are included: (1) Initialization phase After the control module is powered on, it performs initialization operations, including setting the initial state of the LED segment driver module and initializing the data storage module. The control module sets the output of the LED segment driver module to the initial display state, such as all off or displaying a specific pattern. At the same time, it checks whether there is valid display data stored in the data storage module. If so, it reads the data and prepares it for subsequent display control. (2) Normal display stage The control module generates corresponding LED segment display data according to preset display rules or external input signals, and sends the data to the LED segment driver module to drive the LED segment to display the corresponding information. In the electronic clock application, the control module generates corresponding digital display data according to the time information of the internal clock circuit and drives the LED segment to display the current time; The control module regularly stores the current LED segment display data into the data storage module to achieve power-off memory function. The storage cycle can be set according to actual needs, and the display data can be stored once every minute; (3) Power-off detection stage The power failure detection module monitors the power supply voltage in real time. When it detects that the power supply voltage is lower than the reference voltage, it determines that it is a power failure and sends a power failure signal to the control module. (4) Power-off processing stage After receiving the power-off signal, the control module immediately stops the current display operation and urgently stores the current LED segment display data in the data storage module to ensure the integrity and accuracy of the data. The control module can give priority to storing the display data in a specific area of ​​the internal memory and set the corresponding flag bit to distinguish between normal storage and power-off emergency storage data; At the same time, the control module enters low power mode to reduce power consumption during power failure and extend battery life; (5) Power-on recovery phase When the power is turned on again, the control module wakes up from the low power mode and first reads the LED segment display data stored in the data storage module before the power failure; The control module restores the display status of the LED segment according to the display data read, so that the device returns to the operating state before the power failure. After the electronic clock is powered on again, it can display the time set before the power failure. After the electronic instrument is powered on again, it can display the measurement data before the power failure.

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