Local refreshing and low-power-consumption display control system of mining electronic paper display terminal
By employing electronic paper display technology with RS485 bus and BLE Bluetooth communication in mining displays, combined with modular power management and local refresh algorithms, the problems of high power consumption, communication, and maintenance costs in mining displays have been solved. This has enabled low power consumption, flexible communication, and independent data acquisition, ensuring the long-term reliability and safe visibility of underground display terminals.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-26
- Publication Date
- 2026-03-10
AI Technical Summary
Existing mining LED/LCD displays are inadequate in terms of power consumption, battery life, environmental adaptability, and communication flexibility, failing to meet the long-term operational needs of complex underground environments. Furthermore, they cannot independently collect and display information, resulting in high maintenance costs.
It adopts electronic paper display technology combined with RS485 bus and BLE Bluetooth communication to achieve partial refresh and low power consumption control, integrates modular power management, has the ability to acquire multi-parameter sensor data, and supports power-off display retention.
It achieves ultra-low power consumption, flexible communication, and independent data acquisition and display, reducing maintenance costs and ensuring continuous visibility of critical information in the event of power failure or communication interruption, making it suitable for long-term operation in complex downhole environments.
Smart Images
Figure CN121640924A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of display technology and communication technology for mine, in particular to a local refresh and low-power display control system of mine electronic paper display terminal. BACKGROUND
[0002] Most of the existing coal mine underground display devices use LED or LCD light-emitting display technology. Although such devices have the advantages of high brightness, long visual distance, rich display content, etc., their structure is complex, power consumption is high, volume is large, and heat dissipation demand is obvious, which is not conducive to long-term operation in the complex environment of the underground. The power consumption of LED display screen in display state is usually between several watts and tens of watts, and although the power consumption of LCD screen is slightly lower, it still needs to be continuously lit by a backlight source, and there is still a large energy consumption burden. For the distributed installation scene of coal mine underground, such as roadway entrance, tunneling working face, equipment room, personnel entrance, etc., the power supply line is difficult to lay and the maintenance cost is high, and the traditional LED / LCD display screen has obvious shortcomings in power consumption, endurance and environmental adaptability.
[0003] At the system function level, the traditional mine LED display screen is mostly used as a passive display terminal, relying on the display template and data issued by the upper computer, and cannot independently collect information or display the state. Once the communication is interrupted or the upper computer fails, the terminal will not be able to update the content, and can only keep the screen black or display an error picture. At the same time, the display terminal mostly uses RS485 or Ethernet wired communication, which is complex in field wiring and tedious in debugging process, and does not have flexible wireless management capability.
[0004] In recent years, with the promotion of intelligent and digital construction of coal mines, the demand for underground display terminals has shifted from single information publishing to comprehensive intelligent nodes with "local data collection + independent display + ultra-low power consumption operation". However, the traditional light-emitting display technology is limited by power consumption and environmental constraints, and it is difficult to meet the requirements of long-period unattended, low-power standby, power-off display and other new scenarios.
[0005] The emergence of low-power electronic paper (E-Paper) display technology provides a new solution for mine terminal display. Electronic paper uses electrophoresis or microcapsule imaging principles to form images by driving display particles to distribute, and can maintain the picture for a long time without continuous power supply once the display is completed. Unlike LED or LCD, electronic paper is a reflective display medium that does not require a backlight, has high contrast, wide viewing angle, and is clearly visible in strong light. Its typical power consumption is only 1 / 100 of that of traditional LCD, and almost no continuous energy consumption is generated in application scenarios with long refresh intervals. However, electronic paper is prone to ghosting, artifacts, and edge blur in frequent local update scenarios, especially in low temperature and high humidity underground working conditions, where slow particle migration can further lead to a decrease in display quality.
[0006] The existing electronic paper driving mostly adopts a full-screen refreshing mode, and the refreshing consumes a long time and has a large energy consumption; although local refreshing has a low power consumption, there are problems of gray scale residue and uneven reverse polarity. Therefore, a local refreshing control algorithm capable of considering low power consumption, fast updating and anti-image sticking is needed, which is particularly suitable for a mine safety monitoring display terminal.
[0007] The existing monochrome or dual-color display screen has no data acquisition function, and the display method cannot support independent use from the system, the display template and display content need to be issued by the upper computer, the display color is single, the display mode is not flexible, the display content is not rich, full-color dynamic pictures and video playback are not supported, etc., which cannot meet the new functional requirements.
[0008] The existing mine-used LED / LCD intrinsically safe display screen has high brightness, rich display content and intuitive display, but has many technical shortcomings in the underground environment, mainly including the following points: (1) High overall power consumption, not suitable for limited power supply environment The power consumption of LED and LCD screens is usually between several watts and tens of watts in the continuous display state, and it depends on constant power supply. Once the power supply is interrupted, it cannot display. For the terminal laid in the mine roadway, the tunneling face or the area without fixed power supply, it is difficult to realize long-time continuous work, and it is also not suitable for battery power supply or intermittent power supply scenarios.
[0009] (2) Power failure causes display loss, lack of picture retention capability The existing light-emitting display screen will immediately extinguish the display when the power is off or the system is restarted, and it cannot maintain the display of key information after the power supply is interrupted, communication is lost or a safety accident occurs. For mine emergency indication, environmental parameter alarm, personnel information prompt and other occasions, this "display loss" problem seriously affects the safety visibility and information continuity.
[0010] (3) Cannot independently collect sensor data The traditional mine display screen only serves as a passive display terminal, and needs to rely on the content and template issued by the upper computer system, and lacks the direct collection capability of temperature and humidity, gas concentration, equipment running state and other parameters. Once the upper computer communication is interrupted, the terminal cannot update the display in real time and cannot operate independently.
[0011] (4) Difficult to maintain and configure The traditional mine display screen relies on the upper computer and special software for on-site debugging, and for the environment with wide distribution and many nodes in the mine, the wiring and maintenance cost is high, and it does not have the ability of convenient wireless debugging and parameter configuration. SUMMARY
[0012] This invention provides a partial refresh and low-power display control system for a mining electronic paper display terminal. The control system (display screen) uses electronic paper as the core display medium and combines RS485 bus and BLE Bluetooth dual communication mechanisms. Through modular power management circuit, partial refresh algorithm and power-off display retention technology, it achieves comprehensive performance improvement in terms of low power consumption, power-off display retention, no backlight heating, and long life.
[0013] In addition, the display screen adopts an explosion-proof sealed shell and IP65 protection design, which can operate stably in high humidity and high dust environments; it has the ability to acquire and display multi-parameter sensor data locally, and can independently acquire, display and store data in real time from the host computer system, realizing a truly intelligent and scalable mining terminal display platform.
[0014] Specifically, the partial refresh and low-power display control system of the mining electronic paper display terminal of the present invention includes a main control board, a driving module, an electronic paper display module and a communication module; The main control board is connected to the host computer system and serves as the core data processing and control unit, responsible for the acquisition, processing, display control, and communication management of multi-parameter sensor monitoring values. The electronic paper display module is connected to the main control board through the driver module. The electronic paper display module is responsible for presenting the monitoring parameters, status prompts and alarm information in a low-power mode. The communication module is connected to the main control board and the host computer system respectively, which can realize communication between the host computer system and multiple types of sensors, and between the main control board and multiple types of sensors.
[0015] Furthermore, the communication module supports dual communication modes: RS485 bus and BLE Bluetooth. The RS485 bus can simultaneously enable stable communication between the host computer system and the control system, and between the control system and various types of sensors. The BLE Bluetooth allows users to configure parameters and project data onto the display screen via their mobile phones on-site.
[0016] Furthermore, the main control board has embedded display refresh and power management logic. When a data change is detected, it automatically triggers a partial refresh of the electronic paper. When there is no data update, it enters a deep sleep state to reduce power consumption.
[0017] Furthermore, the electronic paper display module adopts electrophoretic reflective display technology, which can clearly display content under strong light conditions without backlighting, and can retain the last image for a long time after power failure.
[0018] The control method for the partial refresh and low-power display control system of the above-mentioned mining electronic paper display terminal specifically includes the following steps: S1 Multi-type sensor data acquisition: Multiple types of sensors are connected to the low-power display control system via RS485 bus to acquire real-time monitoring data from multiple types of sensors; S2 Handheld Terminal Data Configuration and Interaction: The handheld terminal communicates with the low-power display control system via BLE Bluetooth to determine whether a connection is established, send movement commands, receive measurement point data or full-screen data, and verify whether the data is complete. S3 Electronic Paper Display Module Refresh: By driving the row and column drivers of the electronic paper display module, the pixel voltage is switched back and forth, ultimately realizing the display of screen image data; S4 Electronic Paper Display Module Partial Refresh Intelligent Control Strategy: Achieve efficient display control of the electronic paper display module through change monitoring, partial refresh, and anti-image retention control; S5 ePaper Display Module Sleep Wake-up: After the system completes the refresh task, the main control board controls the ePaper Display Module to enter a deep sleep mode, so as to maintain the ePaper Display Module in an ultra-low power consumption state when there is no refresh task, and to respond quickly and restore the state when an external event is triggered.
[0019] Furthermore, in step S1, the method for acquiring data from multiple sensor types is as follows: The main control board wakes up the RS485 bus interface through the communication module within a preset period to establish master-slave or peer-to-peer communication with multiple types of sensors; Poll or receive data frames actively reported by sensors according to sensor type, perform consistency checks on the frame header, length and check code of the data frames, and after the check passes, parse, normalize and judge the validity of the monitoring values according to the measurement point address and parameter type, and write them into the buffer / register to form the current monitoring data; Simultaneously, the monitoring data from the previous cycle is saved for use in change detection and display refresh decisions. Abnormal or failed data frames are discarded and retransmission is triggered or the data enters the next round of collection.
[0020] Furthermore, in step S2, the method for configuring and interacting with handheld terminal data is as follows: The display terminal enables BLE broadcasting and waits for the handheld terminal to connect. After the connection is established, it obtains the connected device ID and enters the configuration interaction state. The handheld terminal sends a movement command to the display terminal, the command including at least a measurement point data transmission command and a full screen / template data transmission command; The display terminal receives the corresponding data according to the command type, and performs integrity judgment on the received data based on the packet sequence number and total number of packets / total length. If the integrity is not satisfied, it sends a retransmission request to the handheld terminal and re-receives the data. After the data is complete, a checksum verification is performed on the data. If the verification fails, the data is received again. If the verification passes, the configuration parameters, measurement point definitions or full-screen image data are written to Flash and the version / effectiveness flag is updated. After the interaction is completed, the connection is disconnected and the system enters a low-power waiting state.
[0021] Furthermore, in step S3, the method for refreshing the electronic paper display module is as follows: The main control board generates a row and column drive sequence based on the target image data to be displayed, selects the drive waveform lookup table corresponding to the refresh mode, and sends it to the drive module. The driving module sequentially performs row scanning and column data loading in the pre-charge / erase / update phases, and performs voltage polarity switching on pixels in a local or full-screen area to form the target image; After the refresh is complete, the main control board shuts off the high-voltage power supply and timing output of the driver module, and latches the last image of the electronic paper display module to ensure power-off retention and low-power display.
[0022] Furthermore, in step S4, the method for the intelligent control strategy of partial refresh of the electronic paper display module is as follows: The main control board performs a differential comparison between the current monitoring data and the previously displayed data, calculates the change, and compares it with a preset threshold or an adaptive threshold. When the change exceeds the threshold, it is determined that a refresh is required. Based on the coordinate mapping table of each measuring point / field in the template, locate the display area corresponding to the changed field, generate a local refresh window, and perform a local refresh only on the window; Simultaneously, the number of consecutive partial refreshes and the cumulative partial refresh time are recorded. When the number or time reaches the anti-ghosting threshold, a full-screen anti-ghosting refresh is automatically triggered to eliminate ghosting and restore display consistency. After that, the partial refresh count is cleared and the change monitoring loop continues.
[0023] Furthermore, in step S5, the method for waking up the electronic paper display module from sleep mode is as follows: After completing partial refresh or full-screen anti-ghosting refresh, the main control board first shuts down the high-voltage output and row and column scanning timing of the driver module, and writes the current display data and refresh status variables into the Flash or RTC holding area. Then, according to the preset power domain strategy, the communication module, sensor power supply and unnecessary peripherals are shut down, leaving only the RTC controller and low power monitoring unit in working state. At the same time, at least one wake-up source is configured. The wake-up source includes one or more of timed wake-up, external event wake-up or local interactive wake-up. External event wake-up includes at least RS485 bus data arrival, BLE connection / command arrival or external GPIO trigger. After the system enters deep sleep, the low-power monitoring unit continuously monitors the wake-up source status. When a valid wake-up event is detected, debouncing / validity confirmation is performed and the system exits sleep. Power supply to each power domain and peripheral clock are restored in sequence, communication module and display driver parameters are reinitialized, the previously saved display data and configuration status are read, and after data resynchronization and change detection are completed, the next round of acquisition-refresh control process is entered. This achieves ultra-low power consumption maintenance during refresh-free tasks and rapid response and status recovery when events are triggered.
[0024] In summary, compared with existing technologies, this invention achieves significant improvements in power consumption, communication, and functional integration, with the following specific technical advantages and effects: (1) Significantly low power consumption and power-off retention characteristics This invention uses electronic paper display technology, which does not require continuous power supply for static display. Its average power consumption per unit time is only about 1 / 50 of that of traditional LED displays. In scenarios where power supply is limited underground and some nodes require battery power, it can achieve long-term offline operation. At the same time, the electronic paper screen has electrophoretic power-off retention characteristics, which can maintain the image unchanged for a long time after power failure, ensuring that critical information remains visible in emergency situations such as power outages and communication interruptions, significantly improving safety and reliability. (2) Flexible communication methods and convenient configuration and maintenance The system integrates RS485 bus and BLE Bluetooth dual communication mechanisms, supporting both centralized control by the host computer and local wireless configuration by handheld terminals, realizing dual-mode communication of "remote management + local interaction"; RS485 communication has anti-interference and long-distance transmission capabilities, while BLE communication facilitates quick configuration and data reading by downhole inspection personnel, significantly reducing on-site maintenance and debugging costs. (3) Supports local acquisition and display of multi-parameter sensors The system has multiple sensor interfaces, which can be connected to various mine safety parameter sensors such as temperature, humidity, methane, carbon monoxide, and oxygen to realize local acquisition, storage and display of multi-source data; the system can operate independently without a host computer connection and display key environmental indicators in real time. (4) Modular low-power design The main control board supports a multi-level sleep mechanism, automatically entering Deep-Sleep mode when there are no tasks. The display section adopts a partial refresh control algorithm, updating pixels only in areas where data changes, reducing unnecessary full-screen refresh operations, further reducing power consumption, and the overall system energy consumption is significantly better than existing LED or LCD display solutions. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the partial refresh and low power consumption display control system of the mining electronic paper display terminal of the present invention; Figure 2 This is a flowchart of the control method for the partial refresh and low power consumption display control system of the mining electronic paper display terminal of the present invention; Figure 3 This is a flowchart of the multi-type sensor data acquisition method of the present invention; Figure 4 This is a flowchart of the handheld terminal data configuration and interaction method of the present invention; Figure 5 This is a flowchart of the electronic paper display module refresh method of the present invention; Figure 6 This is a flowchart of the lookup table (LUT) operation of the electronic paper display module of the present invention; Figure 7 This is a flowchart of the intelligent control strategy method for partial refresh of the electronic paper display module of the present invention; Figure 8 This is a flowchart of the sleep-wake method for the electronic paper display module of the present invention. Detailed Implementation
[0026] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.
[0027] like Figure 1 The partial refresh and low-power display control system of the mining electronic paper display terminal shown includes a main control board, a driver module, an electronic paper display module, and a communication module.
[0028] Specifically, the main control board is connected to the host computer system. As the core data processing and control unit, the main control board (MCU) is responsible for the acquisition, processing, display control, and communication management of multi-parameter sensor monitoring values. The main control board has embedded display refresh and power management logic. When a data change is detected, it automatically triggers a partial refresh of the electronic paper. When there is no data update, it enters a deep sleep state to reduce power consumption.
[0029] Specifically, the electronic paper display module is connected to the main control board via a driver module. The electronic paper display module is responsible for presenting monitoring parameters, status prompts, and alarm information in a low-power manner. The electronic paper module adopts electrophoretic reflective display technology, which can clearly display content under strong light conditions without backlighting and can retain the last image for a long time after power failure.
[0030] Specifically, the communication module is connected to both the main control board and the host computer system, enabling communication between the host computer system and various types of sensors, as well as between the main control board and various types of sensors. The communication module supports both RS485 bus and BLE Bluetooth communication. The RS485 bus allows for stable communication between the host computer system and the control system, and between the control system and various types of sensors simultaneously. BLE Bluetooth facilitates parameter configuration by users on-site via their mobile phones.
[0031] The main control board connects to sensors for methane, carbon monoxide, temperature, humidity, and oxygen via an RS485 bus, enabling real-time data acquisition and local monitoring. The acquired data can be uploaded to a host computer system via RS485 for synchronization with the mine monitoring platform; alternatively, it can be displayed locally on the electronic paper display module (screen), allowing for independent operation even without a network connection. A BLE Bluetooth communication module facilitates wireless interaction between the handheld terminal and the display screen, allowing users to configure display templates, set device parameters, and publish local data via their mobile devices.
[0032] Combination Figure 2 As shown, the control method of the partial refresh and low-power display control system of the above-mentioned mining electronic paper display terminal specifically includes the following steps: S1 Multi-type Sensor Data Acquisition Multiple types of sensors are connected to a low-power display via an RS485 bus. A communication protocol with the sensors is designed to collect real-time monitoring data. By periodically or in real-time inspecting the sensors, data such as sensor type, real-time monitoring values, communication status, and fault information are obtained.
[0033] The interaction process between the display and the sensor is as follows: Figure 3As shown, after the display terminal powers on or exits low power mode via a wake-up event, it enters the data acquisition state. The main control board first broadcasts a "registration command / network access request frame" to the bus side via the RS485 bus to discover online sensors and establish communication relationships. Then, it enters the "whether a sensor response has been received" determination stage. If no valid response is received within the preset waiting window, it is considered that no sensor is currently connected to the network or the link is abnormal. The main control board continues to periodically send registration commands according to the retry strategy until a response is received. If a sensor response frame is received and verified correctly, the main control board assigns a unique "device number / measurement point address" to the sensor based on the device type code / factory ID in the response, writes the "device number—sensor type—communication parameters" into the local mapping table, and returns a confirmation frame, completing the network access binding. After network access is completed, the system enters the polling and inspection phase: the main control board sends query commands to each sensor according to the mapping table order, the sensor returns real-time monitoring data frames, the main control board performs frame header recognition, length verification and CRC / checksum verification on the data frames, after the verification is successful, it parses to obtain information such as sensor type, real-time monitoring value, communication status (such as timeout / packet loss count), fault / alarm flags, etc., and updates the current measurement point cache; if a single sensor times out or fails verification within the polling cycle, the communication abnormality is recorded and re-polling is performed a set number of times, if it still fails, the measurement point is marked as offline and enters the next device number for polling. After each round of polling, the main control board submits the latest valid data to the display task to update the display content (triggering the corresponding measurement point field refresh or full screen refresh), and at the same time resets or increments the idle timer; when the continuous waiting time is detected to be greater than 2 minutes and no new data arrives / no configuration interaction, the main control board shuts down the RS485 transceiver and related peripheral power domains, so that the electronic paper maintains the current screen and the system enters low power mode; in low power mode, only the RTC / low power monitoring unit is kept working to monitor wake-up sources such as timed wake-up or external bus activity, BLE commands, etc. Once a wake-up event occurs, the RS485 interface is reinitialized and the process of registration-assignment-polling data acquisition is returned, thereby realizing a low power acquisition closed loop of "automatic network access, stable inspection, abnormal retry, timeout sleep and fast wake-up".
[0034] The sensor measurement point data is defined in the communication protocol as shown in Table 1 below.
[0035] Table 1 Definition of Sensor Measurement Point Data Table 1 is used to standardize the "measuring point data format and meaning" between the mining electronic paper display terminal and various types of sensors. It clarifies the key parameters such as sensor type, name, range, data amplification factor, unit / symbol, and number of bytes occupied for each measuring point. This facilitates communication protocol parsing, data conversion and restoration (converting to actual values according to the amplification factor), measuring point mapping and display template positioning. It also provides a unified data basis for the configuration of the host computer / handheld terminal and the subsequent expansion of sensor types.
[0036] S2 Handheld Terminal Data Configuration and Interaction The handheld terminal communicates with the display screen via BLE Bluetooth and uses a handheld terminal app to perform functions such as information publishing and display screen parameter configuration. The handheld terminal sends local data to the display screen for display. Configuration functions include device operating mode configuration, address configuration, display template configuration, and measurement point refresh area configuration. The product's configuration information is stored in flash memory; specific data definitions are as follows: [{ "x1": "20", "y1": "90", "x2": "100", "y2": "170", "Installation Location": "Upper corner of the 30119 longwall mining face" "id":”CH4”, Font size: "L || M || S", "mode": "1", "address": "1", "time":"2025-05-16 15:39:00", }}, { In this process, the interaction between the handheld terminal and the display screen via Bluetooth can be broken down into determining whether a connection has been established, sending movement commands, receiving measurement point data or full-screen data, and verifying whether the data is complete.
[0037] The specific process is as follows: Figure 4As shown, this flowchart describes the complete interaction and fault-tolerance mechanism between the display terminal and the handheld terminal via BLE for "local configuration / data distribution". Specifically, it can be explained as follows: After the device starts up, it enters the Bluetooth service process. The main control board first initializes the BLE protocol stack and enables broadcasting (including necessary identifiers such as device name, service UUID, and version number), entering a discoverable / connectable state. Then, the system determines whether a connection has been established. If no handheld terminal has connected, it continues broadcasting and listening, entering a "waiting for connection" loop. When a handheld terminal initiates a connection and completes pairing / encryption (if any), the main control board confirms the successful connection and obtains the connected device ID (such as MAC / conn_handle / binding ID), which is used for subsequent session identification, permission verification, and data receipt. After the connection is established, the display terminal enters the command receiving state, waiting for the handheld terminal to send mobile commands (command words). The commands are divided into two categories: the first is the 0xD2 measurement point data sending command, which is used to configure / update measurement point definitions, parameter values or a small amount of business data; the second is the 0xD3 image / full screen data sending command, which is used to configure templates or send full screen image data. Upon receiving the command, the system enters the corresponding branch: When the command is 0xD2, the terminal begins to receive measurement point data packets (including packet sequence number, total number of packets / length, payload, and check field). For each packet received, the sequence number continuity and length accumulation are checked until completion. Then, a data integrity check is performed. If a missing packet, out-of-order packet, or insufficient length is found, a "retransmission request / missing packet index" is sent to the handheld terminal, and the system returns to the measurement point data receiving state to receive again. If the integrity is satisfied, the entire frame of data is checked for correctness (such as CRC16 / checksum). If the check fails, the data in this round is discarded and a retransmission is requested again. After the check passes, the measurement point data is written to Flash according to the preset format (including version number, timestamp / effectiveness flag), and a "write success ACK" can be sent back. When the command is 0xD3, the terminal receives image / full-screen data using the same packet-splitting mechanism. It first checks the integrity of the data; if incomplete, it requests retransmission and re-receives the data. If complete, it performs a correctness check; if the check fails, it retransmits; if the check succeeds, it stores the image / template data in the corresponding Flash area, updates the template number, compression algorithm number, or display parameters, and sends back a success confirmation. Once any branch has reliably written the data, the system considers the local configuration / distribution task complete. The main control board exits BLE high-power mode, shuts down unnecessary peripherals, and drives display refresh (if needed). It then enters sleep mode to reduce overall power consumption, awaiting the next wake-up or a new connection interaction. The entire process, through a closed loop of "connection maintenance—command routing—integrity check—verification confirmation—failure retransmission—successful Flash storage—low-power sleep," ensures the reliability and low-power operation of configuration and full-screen data distribution in a weak link environment.
[0038] S3 ePaper Display Module Refresh By driving the row and column drivers of the electronic paper display module, the pixel voltage is switched back and forth, ultimately enabling the display of screen image data. The electronic paper display module is developed using E Ink Electronic Paper from E Ink Holdings Co., Ltd. in Taiwan, China. This display has a built-in driver chip and a built-in frame buffer, and uses SPI communication to receive image data and instructions.
[0039] The entire refresh display process is as follows: Figure 5 As shown, Figure 5 The internal structure and workflow of the integrated controller-type electronic paper module are demonstrated: the upper-level processor sends the image / text data to be displayed and refresh control instructions to the display controller within the module. The display controller first temporarily stores the image data in the frame buffer, and then generates the corresponding row and column drive timing based on the waveform lookup table (LUT) and refresh strategy. These timings and pixel data are sent to the display driver on the controllerless electronic paper panel side. The driver loads the data through a shift register, latches it to achieve synchronous operation of the entire row / column, and outputs the actual drive level through the output buffer to act on the TFT pixel array, thereby driving the electrophoretic pixels to form the target image. The power controller below provides the display driver and panel with multi-level high voltage / reference voltage required for refresh and manages the power-on and power-off timings, so that the system can shut down the high voltage domain, maintain the image, and enter a low-power state after the refresh is completed, providing hardware support for partial refresh and low-power display.
[0040] The diagram shows that the controller's look-up table (LUT) is essentially a RAM. The microcontroller pre-writes data into the RAM via SPI. Each input signal is equivalent to inputting an address to look up the table, find the corresponding content, and then output it. By driving the row and column drivers of the display screen, the pixel voltage is switched back and forth, ultimately realizing the display of screen image data.
[0041] The operation process for LUT is as follows: Figure 6As shown, this flowchart describes the typical "power-on—initialization—waveform loading—image writing—entering low power / power-off" process of an electronic paper (EPD) module in one refresh cycle, specifically as follows: After the system powers on, the EPD driver IC is first reset in hardware / software to return its registers, state machine, and internal RAM to a known initial state, avoiding the influence of residual states from the previous refresh on the current display; after the reset, the clock source required by the driver IC is turned on, and the internal voltage regulation / charge pump and other power management units are enabled to generate multiple driving voltages (such as positive and negative high voltage, VCOM, etc.) required for electronic paper refresh step by step, ensuring sufficient voltage conditions for subsequent pixel flipping; after the driving voltage stabilizes, the main controller configures the operating mode of the current display (full screen / partial, black and white / grayscale, temperature range, etc.) and the starting address and write range of the video memory RAM to the driver IC, specifying "where to refresh and in what format to write"; then, the corresponding LU is read and downloaded from the driver IC's OTP (one-time programmable memory area). The T-waveform table is transferred to the working area. The LUT is used to specify the driving waveform sequence of pixels at different stages, which is a key parameter that determines the refresh effect, speed, and ghosting suppression. After the LUT takes effect, the main controller writes the image data to be displayed into the RAM of the driver IC in row and column order and triggers the update action. The driver IC performs the erase / update and other stages of driving the panel pixels according to the configured display mode and LUT until the image is fully displayed. After the refresh is completed, the system enters one of two closing states according to the application strategy: if a complete power cut is required, it executes "power off", shuts off the high voltage and clock and stops working; if it is required to maintain the screen for a long time and standby with extremely low power consumption, it enters "deep sleep", retains the necessary wake-up detection and minimum power domain, and re-enters the reset and initialization process after the external wake-up event arrives, and starts the next round of display update.
[0042] The LUT operation mainly involves manipulating the addresses of fixed registers inside the chip. The contents of the registers for the partial refresh of this LUT are as follows: const unsigned char Lut_Partial[]={ 0x15, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x2A, 0x88, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x15, 0x44, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x00, 0x0A, 0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x22, 0x22, 0x22, 0x22, 0x22, 0x17, 0x41, 0xA8, 0x32, 0x18, 0x00, 0x00, }; The address of each register in the above array represents a different waveform file. Different display effects can be achieved by manipulating the registers using the API functions in the table below: Table 2 Refresh Function Definitions S4 Electronic Paper Display Module Partial Refresh Intelligent Control Strategy To address the issues of high power consumption and noticeable image retention caused by frequent screen refreshes, this application proposes an intelligent display control method that achieves efficient display control through change monitoring, partial refresh, and anti-image retention control.
[0043] S4.1 Data Change Detection ① The display screen and the sensor communicate and transmit data via RS485, and save the data to the corresponding data buffer of the measuring point according to the type of different measuring points.
[0044] ② Compare the currently displayed data with the data from the last refresh, and calculate the change in each displayed field.
[0045] ③ When the change exceeds the preset threshold, the field is determined to have changed significantly, thereby triggering a refresh operation.
[0046] S4.2, Local Area Refresh ① The display screen maps the changing fields to the corresponding coordinate areas within the predefined display area of the display template based on the configuration information sent by the mobile APP via Bluetooth BLE.
[0047] ② The display screen only refreshes the area where changes are detected, while the rest of the screen remains unchanged.
[0048] S4.3, Anti-image retention control ① The system records the number of consecutive refreshes for each local refresh area and saves the number of refreshes in the flash area.
[0049] ② When the number of local refreshes exceeds the preset threshold, the system first saves the template data of the entire display screen in the template space, and then automatically triggers a full-screen refresh operation to eliminate the ghosting phenomenon.
[0050] The workflow of the partial refresh intelligent control strategy for the electronic paper display module is as follows: Figure 7 As shown, the process of this partial refresh intelligent control strategy can be broken down into a closed loop of "change detection - partial refresh - counting - anti-image full refresh - reset cycle" according to the diagram. The specific working process is as follows: After system startup, the main control board first initializes the display cache and sets interface / template parameters, including: reading previously displayed data as the "historical display cache," and loading UI and refresh control parameters such as coordinate mapping, font size, refresh area boundaries, and change thresholds for each measurement point / field in the current template. Then, it enters the main loop to calculate the change in newly acquired sensor data: comparing the current monitored value with the historical display cache field by field to obtain the difference value for each measurement point (which can be an absolute difference, a relative difference, or a physical quantity difference after magnification). Invalid data can be filtered out based on sensor validity and communication status. The main control board then enters the judgment phase based on the difference results—whether the threshold is exceeded: if all field changes do not reach the preset / adaptive threshold, the displayed content is considered not to need updating, the system does not trigger a refresh, and directly returns to the change calculation stage for continuous monitoring; if one or more field changes exceed the threshold, a refresh request is generated, the display area corresponding to these changed fields is located based on the template coordinate mapping, and a partial electronic paper refresh is performed, outputting the refresh waveform only for the changed local window, thereby reducing refresh time and energy consumption. After each partial refresh, the system accumulates the number of partial refreshes (or the duration / area of partial refreshes) and updates the historical display cache to the latest display value. Then, it enters the anti-ghosting judgment stage to determine whether the number of partial refreshes exceeds the threshold: If the number of partial refreshes has not reached the anti-ghosting threshold (e.g., within N consecutive partial refreshes), a full-screen refresh is not performed, and the system directly returns to the change calculation to continue the next round of change monitoring and on-demand partial refresh; if the number of partial refreshes reaches or exceeds the threshold, a global refresh (full-screen anti-ghosting refresh) is triggered, using the full refresh waveform to uniformly erase and rewrite all pixels on the screen to eliminate the ghosting / grayscale inconsistency problem that may be caused by long-term partial refreshes. After the global refresh is completed, the system resets the number of partial refreshes to zero, while keeping the latest display cache and interface parameters unchanged, and returns to the starting point of the main loop to continue the next round of intelligent refresh control of "change detection - on-demand partial refresh - counting - anti-ghosting full refresh".
[0051] With this strategy, the system does not refresh at all when the data is stable, but only performs low-power change monitoring; when the data changes locally, it only refreshes the changed area; and when continuous partial refreshes accumulate to a certain extent, it automatically refreshes the entire screen to eliminate ghosting, thus balancing display effect, refresh efficiency and ultra-low power operation.
[0052] The following table lists the API functions called in this function: Table 3 Local refresh strategy function definition S5 ePaper Display Module Sleep / Wake-up To meet the low-power operation requirements of underground electronic paper display terminals, this invention introduces a deep sleep and fast wake-up mechanism after the display task is completed, so as to minimize system power consumption while ensuring response speed.
[0053] After completing the display refresh task, the main control board enters a deep sleep mode. Before entering sleep mode, the system first configures a specific GPIO pin as an external wake-up source and sets it to a high-level trigger condition. After entering sleep mode, except for necessary low-power units such as the RTC controller, RTC memory, and ULP coprocessor, all other peripheral circuits (including communication interfaces, sensor modules, and display driver modules) are powered off, thereby achieving a microampere-level static power consumption state.
[0054] During sleep mode, the system continuously monitors the level changes of the wake-up GPIO pin via the RTC module. When the pin reaches the preset trigger condition, the RTC sends a wake-up signal to the main control core, initiating the wake-up process. At this time, the main control chip performs a startup process similar to power-on reset, but the data and key flag bits in the RTC memory are retained.
[0055] After the system wakes up, the main program first reads the reset reason register to determine if this startup is a "deep sleep wake-up" event. If the determination is correct, the normal global initialization steps are skipped, and the system running state and key parameters (such as sensor sampling period, display cache flag, communication connection status, etc.) saved before hibernation are directly restored from the RTC storage area. This design can effectively shorten the wake-up response time and avoid the energy loss caused by repeated initialization.
[0056] Through the above-mentioned sleep and wake-up mechanisms, the present invention achieves ultra-low power consumption maintenance of the electronic paper display terminal when there is no refresh task, as well as rapid response and state recovery when external events are triggered, thereby significantly extending the battery life of the device and improving the reliability of the system.
[0057] The process of the sleep-wake method for the electronic paper display module is as follows: Figure 8As shown, after the system completes a display refresh or enters standby mode, the main control board first enters the hibernation preparation process. It configures the wake-up GPIO as an external wake-up source (e.g., button / magnetic contact / substation bus activity indicator / sensor ready signal), sets the trigger level and interrupt type, and completes the necessary debouncing / filtering parameter configuration. Simultaneously (within this step), it shuts down the high-voltage power supply and timing output required by the electronic paper driver, writes key operating information such as the current display status, cache pointer, partial refresh count, and template / version number to the RTC storage area or Flash, and sets the "hibernation flag" to ensure the system can resume context after a power outage during hibernation. Subsequently, the main control board issues a deep hibernation command, and the system enters deep hibernation mode: except for the RTC controller and low-power monitoring unit, all other power domains and peripheral clocks are turned off, and the electronic paper panel retains the last image without consuming power. During hibernation, the low-power unit continuously monitors the wake-up GPIO and other wake-up sources (such as RTC timing, bus edge, BLE wake-up, etc.) and continuously checks whether the trigger condition is met. If not triggered, it remains in hibernation without action. When a local external event meets the triggering conditions, the RTC / low-power unit initiates the wake-up path, the system exits deep sleep and executes the wake-up process: validating and debouncing the wake-up source, re-energizing key power domains and clock, and resuming CPU operation. Next, the main control board reads the RTC's stored flags to obtain the system context saved before the last sleep (e.g., wake-up reason, pending tasks, displayed data version, local refresh count, etc.), and determines subsequent actions accordingly: if data re-acquisition is required, the communication module is initialized and the acquisition process begins; if only a timed wake-up is needed, change detection and on-demand refresh are performed. Finally, the system completes peripheral reinitialization and status write-back, restoring the system to normal operating state, returning to the closed-loop control of "acquisition—refresh—low-power sleep," enabling the e-paper terminal to maintain ultra-low power consumption when there are no tasks, and to quickly wake up and seamlessly resume operation when triggered by external events.
[0058] The following interface function is called during this process. Table 4. API function definitions for display sleep / wake-up The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape, principle and application direction of this application should be covered within the scope of protection of this application.
Claims
1. A local refresh and low power display control system for a mining electronic paper display terminal, characterized in that, The application relates to a low-power display control system, which comprises a main control board, a driving module, an electronic paper display module and a communication module. The main control board is connected with an upper computer system and serves as a core data processing and control unit, is responsible for the collection, processing, display control and communication management of monitoring values of multiple parameter sensors. The electronic paper display module is connected with the main control board through the driving module, and is responsible for presenting monitoring parameters, state prompts and alarm information in a low-power mode. The communication module is connected with the main control board and the upper computer system, and can realize the communication between the upper computer system and multiple types of sensors and between the main control board and multiple types of sensors.
2. The local refresh and low power display control system of the electronic paper display terminal for mine according to claim 1, characterized in that: The communication module supports RS485 bus and BLE Bluetooth double communication modes, the RS485 bus can realize stable communication between the upper computer system and the control system and between the control system and multiple types of sensors, and the BLE Bluetooth is convenient for users to configure parameters and display picture data on the spot through mobile phones.
3. The local refresh and low power display control system of the electronic paper display terminal for mine according to claim 2, characterized in that: The main control board is embedded with display refreshing and power management logic, and can automatically trigger local refreshing of the electronic paper when detecting data changes and enter a deep sleep state to reduce power consumption when there is no data update.
4. The local refresh and low power display control system of the electronic paper display terminal for mine according to claim 3, characterized in that: The electronic paper display module adopts electrophoretic reflective display technology, can clearly display contents under strong light conditions without backlight, and can keep the last picture for a long time after power failure.
5. The control method of the partial refresh and low power display control system of the electronic paper display terminal for mine according to any one of claims 1-4, characterized in that, The application further discloses a low-power display control method, which comprises the following steps: S1, multiple types of sensor data collection: multiple types of sensors are connected with a low-power display control system through an RS485 bus to collect real-time monitoring data of the multiple types of sensors; S2, handheld terminal data configuration and interaction: a handheld terminal is connected with the low-power display control system through BLE Bluetooth to judge whether a connection is established, send a mobile command, receive point data or whole screen data and check whether data is complete; S3, electronic paper display module refreshing: row and column drivers of the electronic paper display module are driven to realize back-and-forth switching of pixel voltage and finally realize display of screen image data; S4, electronic paper display module local refreshing intelligent control strategy: efficient display control of the electronic paper display module is realized through change monitoring, local refreshing and anti-image sticking control; S5, electronic paper display module sleep and wake-up: after the refreshing task is completed, the main control board controls the electronic paper display module to enter a deep sleep mode, realizes an ultralow-power maintaining state of the electronic paper display module when there is no refreshing task and realizes quick response and state recovery when an external event is triggered.
6. The control method of the partial refresh and low power display control system of the electronic paper display terminal for mine according to claim 5, characterized in that: In step S1, the multiple types of sensor data collection method is as follows: The main control board wakes up the RS485 bus interface in a preset period through the communication module, establishes master-slave or peer-to-peer communication with multiple types of sensors; Data frames actively reported by the sensors are polled or received according to sensor types, frame header, length and consistency detection of check codes are carried out on the data frames, after the check passes, monitoring values are parsed, normalized and validity judged according to point addresses and parameter types, and are written into a buffer area / register to form current monitoring data; Meanwhile, last period monitoring data are saved for change detection and display refreshing decision, and abnormal or check failed data frames are discarded and retransmission or next round collection is triggered.
7. The control method of the partial refresh and low power display control system of the electronic paper display terminal for mine according to claim 6, characterized in that, In step S2, the handheld terminal data configuration and interaction method is as follows: The display terminal enables BLE broadcast and waits for the handheld terminal to connect, acquires the connection device ID after connection establishment, and enters a configuration interaction state; The handheld terminal sends a moving command to the display terminal, and the command at least includes a measuring point data issuing command and a whole screen / template data issuing command; The display terminal receives corresponding data according to the command type, and performs integrity judgment on the received data based on the packet number, total packet number / total length, feeds back a retransmission request to the handheld terminal when the integrity does not meet the requirement, and re-receives; After the data integrity, the data is subjected to a check code check, re-received when the check fails, and written into the Flash and the version / version flag is updated when the check passes, the connection is disconnected after the interaction is completed, and a low-power consumption waiting state is entered.
8. The control method of the partial refresh and low power display control system of the electronic paper display terminal for mine according to claim 7, characterized in that, In step S3, the method for refreshing the electronic paper display module is as follows: The main control board generates a row-column driving sequence according to the target image data to be displayed, selects a driving waveform lookup table corresponding to the refresh mode, and sends it to the driving module; The driving module sequentially performs row scanning and column data loading in the pre-charge / erase / update phase to complete voltage polarity switching of the pixel points in the local or whole screen area to form the target image; After the refresh is completed, the main control board closes the high-voltage power supply and timing output of the driving module, and locks the last picture of the electronic paper display module to ensure power-off retention and low-power consumption display.
9. The control method of the partial refresh and low power display control system of the electronic paper display terminal for mine according to claim 8, characterized in that, In step S4, the method for intelligent control of local refresh of the electronic paper display module is as follows: The main control board differentially compares the current monitoring data with the last display data, calculates the change amount, and compares it with the preset threshold or the adaptive threshold, and determines that refresh is required when the change amount exceeds the threshold; According to the coordinate mapping table of each measuring point / field in the template, the display area corresponding to the changed field is located, a local refresh window is generated, and only the window is subjected to local refresh; At the same time, the number of consecutive local refreshes and the cumulative local refresh time are recorded, and when the number or time reaches the anti-fouling threshold, a full-screen anti-fouling refresh is automatically triggered to eliminate the residual image and restore the display consistency, and then the local refresh count is cleared and the change monitoring loop is continued.
10. The control method of the partial refresh and low power display control system of the electronic paper display terminal for mine according to claim 9, characterized in that, In step S5, the method for hibernation and wake-up of the electronic paper display module is as follows: After completing the local refresh or full-screen anti-fouling refresh, the main control board first closes the high-voltage output and row-column scanning timing of the driving module, and writes the current display data and refresh state variables into the Flash or RTC retention area; Subsequently, according to the preset power domain strategy, the communication module, sensor power supply and unnecessary peripherals are closed, only the RTC controller and low-power consumption monitoring unit are kept in working state, at least one wake-up source is configured, the wake-up source includes one or more of timing wake-up, external event wake-up or local interaction wake-up, and the external event wake-up at least includes RS485 bus data arrival, BLE connection / instruction arrival or external GPIO triggering; The system continuously monitors the state of the wake-up source by the low-power monitoring unit after entering deep sleep, performs debouncing / validity confirmation and exits sleep when detecting a valid wake-up event, sequentially restores power supply of each power domain and peripheral clock, reinitializes the communication module and display driving parameters, reads the last saved display data and configuration state, enters the next round of acquisition-refresh control process after completing data resynchronization and change detection, thereby realizing ultra-low power consumption maintenance when there is no refresh task and fast response and state recovery when triggered by an event.