Code table screen projection control method and system based on ambient light induction

Abstract

The invention relates to the technical field of screen projection control, and discloses a code table screen projection control method and system based on ambient light induction. The method comprises the following steps: acquiring first ambient light illuminance through an ambient light sensor in a code table and extracting a median to obtain second ambient light illuminance and a corresponding illumination grade index; looking up a table from a preset standard screen projection matrix according to the illumination level index to read a corresponding first screen projection parameter; a link quality index and an equipment load index between the code table and the external information source equipment are calculated and corrected, and a second screen projection parameter is obtained; and performing interpolation on the screen projection parameter output in the previous control period and the second screen projection parameter in a preset transition period number, packaging into a screen projection control message, and sending the screen projection control message to external information source equipment. According to the invention, the technical problems of slow parameter response, poor adaptability and unsmooth switching in the prior art are solved, and the real-time performance, the stability and the user experience of the code table screen projection process in a complex illumination environment are improved.

Description

Technical Field

[0001] This invention relates to the field of screen projection control technology, and in particular to a method and system for controlling screen projection using a code meter based on ambient light sensing. Background Technology

[0002] The process of projecting cycling computers onto screens faces the challenge of drastic changes in ambient light. Existing technologies employ real-time optimization algorithms to dynamically calculate projection parameters based on current lighting conditions. This approach requires multi-objective optimization solutions to be performed with each change in ambient light, resulting in long parameter response delays and consuming significant computational resources, making it difficult to meet the real-time requirements of outdoor cycling. Existing technologies adjust parameters based on only a single time-varying factor. When wireless link quality fluctuates or the cycling computer's own processing load changes, it cannot simultaneously consider the coordinated adaptation of network transmission quality and device processing capabilities. This easily leads to problems such as increased packet loss rates when the link deteriorates or decoding stuttering when the cycling computer is overloaded. When ambient light fluctuates frequently near threshold boundaries, repeated abrupt changes in projection parameters cause flickering, tearing, or even blackouts in the cycling computer display, affecting projection stability and user experience. Summary of the Invention

[0003] The main objective of this invention is to provide a method and system for controlling the projection of a code table based on ambient light sensing. This invention solves the technical problems of slow parameter response, poor adaptability, and uneven switching in the prior art, and improves the real-time performance, stability, and user experience of the code table projection process in complex lighting environments.

[0004] To achieve the above objectives, the present invention provides a method for controlling the projection of a code table based on ambient light sensing, comprising the following steps: The first ambient light intensity is collected by the ambient light sensor in the code table and the median is extracted to obtain the second ambient light intensity. The second ambient light intensity is then mapped to the corresponding light level index. The corresponding first projection parameter is retrieved from the preset standard projection matrix based on the illumination level index; The link quality index and device load index between the code table and the external information source device are calculated, and the baseline coding bit rate and baseline refresh frame rate in the first projection parameters are corrected to obtain the second projection parameters. The projection parameters output in the previous control cycle and the second projection parameters are interpolated within a preset number of transition cycles, encapsulated into a projection control message, and sent to an external information source device.

[0005] Optionally, in a first implementation of the first aspect of the present invention, the step of collecting a first ambient light intensity and extracting the median from an ambient light sensor in a code table to obtain a second ambient light intensity, and mapping the second ambient light intensity to a corresponding illuminance level index, includes: The main control chip of the code meter periodically reads the first ambient light illuminance from the data register of the ambient light sensor via the digital bus; The first ambient illuminance is sequentially written into a circular buffer queue of a preset length to obtain an illuminance filtering queue. The first ambient illuminance in the illuminance filtering queue is sorted and the median is extracted to obtain the second ambient illuminance. Map the second ambient light intensity to the corresponding light level index.

[0006] Optionally, in a second implementation of the first aspect of the present invention, mapping the second ambient illuminance to the corresponding illuminance level index includes: The illuminance continuous domain is divided into six non-overlapping quantization intervals based on the first, second, third, fourth, and fifth illuminance segmentation thresholds. Hysteresis ratio coefficients are set for the first to the fifth illumination segment thresholds, and the rise and fall judgment thresholds corresponding to each illumination segment threshold are calculated. The code table main control chip compares the second ambient light intensity with the rising and falling judgment thresholds in a nested manner based on the current light level. When the second ambient light intensity exceeds the corresponding rising judgment threshold, the level increment operation is performed. When the second ambient light intensity is lower than the corresponding falling judgment threshold, the level decrement operation is performed. Otherwise, the current light level remains unchanged, thus obtaining the light level index.

[0007] Optionally, in a third implementation of the first aspect of the present invention, the step of looking up the corresponding first projection parameter from a preset standard projection matrix according to the illumination level index includes: The code table main control chip reads the storage base address of the standard projection matrix from the base address register of the read-only memory, calculates the address offset of the target row according to the product of the illumination level index and the preset row byte length, and adds the storage base address and the address offset to obtain the starting address of the target row. The code table master control chip sequentially reads matrix element data from four consecutive storage addresses: the target row start address, the target row start address plus the first column offset, the target row start address plus the second column offset, and the target row start address plus the third column offset, to obtain four parameter values ​​to be verified. The code table main control chip performs a boundary validity judgment within a preset range on the four parameter values ​​to be verified. When all four parameter values ​​to be verified pass the boundary validity judgment, the four parameter values ​​to be verified are used as the first projection parameters. The first projection parameters include the reference display brightness, the reference encoding bit rate, the reference transmission resolution, and the reference refresh frame rate.

[0008] Optionally, in a fourth implementation of the first aspect of the present invention, the link quality index and device load index between the calculated code table and the external information source device are used to correct the baseline coding bitrate and baseline refresh frame rate in the first projection parameters to obtain the second projection parameters, including: The code table master control chip reads the first received signal strength value from the signal strength register of the wireless module through the serial bus, adds a preset negative offset compensation value to the first received signal strength value to obtain the second received signal strength value, and then divides the second received signal strength value by a preset normalization divisor to obtain the link quality index. The code table main control chip reads its own processor's utilization status register to obtain the processor utilization rate, and divides the processor utilization rate by a percentage base to obtain the device load index; The baseline encoding bitrate and baseline refresh frame rate in the first projection parameters are corrected based on the link quality index and the device load index, respectively, to obtain the second projection parameters.

[0009] Optionally, in a fifth implementation of the first aspect of the present invention, the step of correcting the baseline coding bitrate and baseline refresh frame rate in the first projection parameters according to the link quality index and the device load index to obtain the second projection parameters includes: The link correction coefficient is determined based on the link quality index and the first preset threshold. The target coding rate is obtained by multiplying the baseline coding rate in the first projection parameters with the link correction coefficient. The equipment load correction coefficient is determined based on the equipment load index and the second preset threshold. The target refresh rate is obtained by multiplying the baseline refresh rate in the first projection parameters with the device load correction coefficient. The target encoding bitrate, the target refresh frame rate, and the reference display brightness and reference transmission resolution in the first projection parameters are assembled to obtain the second projection parameters.

[0010] Optionally, in a sixth implementation of the first aspect of the present invention, determining the link correction coefficient based on the link quality index and a first preset threshold includes: When the link quality index is greater than or equal to the first preset threshold, the link correction coefficient is set to a unit value; When the link quality index is less than the first preset threshold, the link quality index is divided by the first preset threshold and linearly calculated with the preset first attenuation parameter to obtain the link correction coefficient.

[0011] Optionally, in a seventh implementation of the first aspect of the present invention, determining the equipment load correction coefficient based on the equipment load index and the second preset threshold includes: When the equipment load index is less than or equal to the second preset threshold, the equipment load correction coefficient is set to a unit value. When the equipment load index is greater than the second preset threshold, the difference between the equipment load index and the second preset threshold is divided by the preset load range and linearly calculated with the preset attenuation amplitude to obtain the equipment load correction coefficient.

[0012] Optionally, in the eighth implementation of the first aspect of the present invention, the step of performing linear interpolation smoothing on the projection parameters output in the previous control cycle and the second projection parameters within a preset number of transition cycles, and encapsulating them into a projection control message for transmission to an external information source device, includes: The code table main control chip initializes the transition cycle counter to zero and reads the projection parameters output from the previous control cycle from the parameter history cache register; The interpolation weighting coefficient is obtained by dividing the current count value of the transition period counter by the preset number of transition periods. The difference between the projection parameters output in the previous control cycle and the second projection parameters is multiplied by the interpolation weight coefficient and then added to the projection parameters output in the previous control cycle to obtain the interpolation projection parameters for the current cycle. The code table main control chip sequentially encodes the interpolated projection parameters of the current period and adds a cyclic redundancy check code to encapsulate them into a projection control message, which is then sent to an external information source device through a wireless module. The transition period counter is incremented until the preset number of transition periods is reached.

[0013] This invention also provides a clock display projection control system based on ambient light sensing, comprising: The acquisition module is used to acquire the first ambient light illuminance through the ambient light sensor in the code table and extract the median to obtain the second ambient light illuminance, and map the second ambient light illuminance to the corresponding light level index. The reading module is used to look up the corresponding first projection parameter from the preset standard projection matrix according to the illumination level index; The correction module is used to calculate the link quality index and device load index between the code table and the external information source device, and correct the base coding bit rate and base refresh frame rate in the first projection parameters to obtain the second projection parameters. The sending module is used to interpolate the projection parameters output in the previous control cycle and the second projection parameters within a preset number of transition cycles, encapsulate them into a projection control message, and send it to an external information source device.

[0014] In summary, this invention transforms the complex multi-parameter optimization problem into a direct lookup operation based on the illumination level index by pre-constructing a standard projection matrix embedded in read-only memory. This avoids the latency and resource consumption caused by real-time optimization calculations, achieving rapid response from illumination acquisition to parameter output. By introducing a segmented quantization mapping mechanism with hysteresis windows, the impact of frequent fluctuations in ambient illumination near the threshold boundary on the quantization level is effectively suppressed, improving the stability of illumination level determination. Through a dual-index decoupled adaptive correction process for link quality and device load indices, the encoding rate and refresh frame rate are independently corrected for wireless transmission quality and the code table's own processing capabilities, achieving coordinated adaptive control of network status and code table device status, avoiding local optimization problems caused by single-factor adjustments. Changing the parameter switching process from step output to gradual output eliminates screen flickering and tearing caused by parameter abrupt changes, ensuring the continuity of projection parameter changes and visual comfort. This invention solves the technical problems of slow parameter response, poor adaptability, and unsmooth switching in existing technologies, improving the real-time performance, stability, and user experience of the code table projection process in complex lighting environments. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the steps of a code table projection control method based on ambient light sensing in one embodiment of the present invention; Figure 2 This is a block diagram of a code meter projection control system based on ambient light sensing in one embodiment of the present invention.

[0016] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 merely illustrative and not intended to limit the invention.

[0018] Reference Figure 1 This embodiment provides a method for controlling the projection of a code table based on ambient light sensing, including the following steps: S1, collect the first ambient light intensity through the ambient light sensor in the code table and extract the median to obtain the second ambient light intensity, and map the second ambient light intensity to the corresponding light level index; This invention relates to a screen projection control process that projects information from external information source devices onto the display screen of a smart cycling computer. These external information source devices include, but are not limited to, smartphones, smartwatches, cadence sensors, heart rate chest straps, and other cycling-related smart devices. During actual cycling, important information such as incoming calls, SMS notifications, and social media message pushes from the mobile phone, as well as real-time motion data collected by various sensor devices, such as real-time heart rate, cadence, and power output, all need to be transmitted to the cycling computer via a wireless communication link and displayed on its screen. This invention aims to improve the information integration capabilities and intelligence level of smart cycling computers, making them the intelligent control center and information display hub for cycling. Cyclists can centrally access all key information on the cycling computer screen without frequently checking their phones or other devices, thus maintaining focus on cycling while simultaneously keeping track of communication information and motion data. By adaptively adjusting the projection display parameters according to real-time changes in outdoor ambient light, the cycling computer screen maintains a clear and readable display under various complex lighting conditions, such as strong direct sunlight, cloudy low light, and nighttime cycling. At the same time, it takes into account the coordinated control of wireless link quality fluctuations and the cycling computer's own processing load. This invention improves the convenience, safety, and user experience of information acquisition during cycling.

[0019] Specifically, the communication interface between the codebook main control chip and the ambient light sensor is configured in the hardware system, using I... 2 A periodic sampling mechanism is implemented using low-power digital buses such as C or SPI. The main control chip has an internal timer interrupt service routine that triggers ambient light data reading operations at a fixed sampling period. Whenever an interrupt occurs, the main control chip reads the current first ambient light illuminance value from the ambient light sensor's data register via the bus protocol. This first ambient light illuminance value is represented as a 16-bit unsigned integer, representing the digital representation of the current light intensity. The first ambient light illuminance values ​​are written sequentially into a predefined circular buffer queue. The buffer length is fixed, set to 5 or 7 to extract local statistical features of short-term historical light information. The oldest data sample is automatically removed each time new data is added to the queue, and the buffer content is continuously updated. A quick sort operation is performed on all first ambient light illuminance values ​​in the current illuminance filtering queue, and the median value in the middle position of the sorted sequence is extracted and defined as the second ambient light illuminance. The second ambient light illuminance is used as an input parameter for light level judgment. Segmented comparisons are performed based on a set multi-level light threshold range. After completing the ordered interval judgment, discrete light level index values ​​are output.

[0020] S2, read the corresponding first projection parameter from the preset standard projection matrix according to the illumination level index; Specifically, the code table main control chip has already written the complete standard projection matrix into the designated address space of its internal read-only memory (ROM) through offline calibration during the factory stage. The standard projection matrix is ​​stored in the form of a two-dimensional array, with each row corresponding to a lighting level index. Each row contains a fixed number of parameter items, representing the baseline display brightness, baseline encoding bitrate, baseline transmission resolution, and baseline refresh frame rate in sequence. During operation, the main control chip reads the matrix base address value stored in the base address register to obtain the physical starting position of the matrix in the ROM. Using the lighting level index as the row number and combining it with the preset row byte length parameter (each row occupies 8 bytes, 4 unsigned 16-bit integers), it calculates the address offset of the target row corresponding to the current lighting level. The address offset is then added to the stored base address to obtain the starting address of the target row. Following the linear address space incrementing rule, the main control chip continuously reads four 16-bit parameter data points from the target row's starting address, plus a 2-byte offset, plus a 4-byte offset, and plus a 6-byte offset, respectively. These four data values ​​constitute the original output vector of the current lookup result, corresponding to the recommended display brightness value (in nits), encoding bitrate value (in Kbps), transmission resolution enumeration value (e.g., 0 represents 480P, 1 represents 720P, and 2 represents 1080P), and refresh rate value (in fps) for the current lighting level. Boundary validity checks are performed on each of the four parameter values. The brightness parameter must be within the preset range of 50 to 800 nits, the encoding bitrate must be between 1000 and 6000 Kbps, the resolution parameter must belong to the predefined discrete value set {0, 1, 2}, and the frame rate parameter should be within one of the three allowed frame rates: 24, 30, or 60 fps. Only when all four parameters pass the boundary checks does the main control chip confirm the set of parameters as valid output and use it as the first projection parameter for this control cycle. If any parameter fails the validity check, the main control chip considers the matrix data in the ROM to be corrupted or invalid, and automatically calls the built-in default safety parameter group, such as setting the brightness to 250 nits, bit rate to 2500Kbps, resolution to 720P, and frame rate to 30fps to ensure system stability.

[0021] S3, calculate the link quality index and device load index between the code table and the external information source device, and correct the base coding bit rate and base refresh frame rate in the first projection parameters to obtain the second projection parameters; It should be noted that the code table master control chip establishes communication with the wireless communication module through a configured serial bus interface (such as SPI or UART), and actively initiates a read request to the wireless module within the control cycle to obtain the current first received signal strength value from the signal strength register. A preset negative offset compensation value, such as -5dBm or -7dBm, is added to the first received signal strength value to obtain the corrected second received signal strength value. The second received signal strength value is input into a normalization function, and a linear mapping is performed using a fixed normalization divisor, for example, choosing 50 as the denominator and adding a constant term for adjustment, so that the signal strength between -90dBm and -40dBm is mapped to a link quality index between 0 and 1. The closer the link quality index is to 1, the better the transmission quality. Simultaneously, the code table master control chip reads its own processor utilization status register to obtain the current processor utilization value of the code table master control chip. This value is presented in percentage form, indicating the current computational resource usage of the code table. Dividing the percentage value by the percentage base of 100 yields a standardized device load index, ranging from 0 to 1, where a higher value indicates the code table's processing capacity is closer to saturation. The baseline encoding bitrate and baseline refresh frame rate in the first projection parameters are adjusted according to a preset piecewise linear correction function. If the link quality index is less than a specific threshold (e.g., 0.7), it indicates an instability risk in the current transmission link, and the baseline encoding bitrate is reduced linearly to prevent excessive bitrate-induced packet loss; if the link quality is good, the original value remains unchanged. Similarly, if the device load index is higher than a warning threshold (e.g., 0.6), it indicates that the code table's decoding processing capacity is approaching its limit, and the main control chip implements a downgrading strategy for the baseline frame rate to reduce the decoding pressure on the code table; if the load is light, the baseline frame rate is maintained. This ultimately forms the second projection parameter, which includes the corrected encoding bitrate and refresh frame rate.

[0022] S4 interpolates the projection parameters output in the previous control cycle and the second projection parameters within a preset number of transition cycles, encapsulates them into a projection control message, and sends it to the external information source device.

[0023] Specifically, at the beginning of each control cycle, the code table main control chip initializes a transition cycle counter to track the interpolation process. The initial value of the counter is set to zero, indicating that the current stage is the first cycle of parameter interpolation transition. The main control chip reads the projection parameter set output to the external information source device from its internal parameter history cache register. This set includes four items: display brightness, encoding bitrate, transmission resolution, and refresh rate. The projection parameter set serves as the starting point for interpolation and remains unchanged throughout the transition phase. A division operation is performed based on the current transition cycle counter value and the preset total number of transition cycles (e.g., set to 8 cycles) to calculate an interpolation weight coefficient between 0 and 1. This weight coefficient gradually increases from 0 to 1 during the interpolation process to dynamically adjust the interpolation level. The differences between the parameter values ​​of the previous cycle and the current target parameter value (i.e., the second projection parameter) are calculated, and the difference vector is multiplied by the current cycle's interpolation weight coefficient. The product is then added to the original parameter vector of the previous cycle to obtain the interpolated projection parameters corresponding to the current control cycle. For enumerated parameters such as resolution, a threshold method is used. When the interpolation weight is less than 0.5, the value of the previous cycle is retained; when it is greater than or equal to 0.5, the target parameter value is switched to. This segmented switching strategy avoids frequent switching that could cause abnormal processing at the receiving end. After obtaining the interpolation parameters for the current cycle, the main control chip initiates the data packaging process. Using the set protocol format, the four parameters are sequentially encoded into field segments and a projection control message is generated. Each parameter field in the message is laid out in the Type-Length-Value format. The brightness parameter is encoded with 2 bytes, the bit rate with 4 bytes, and the resolution and frame rate are each encoded with 1 byte. The main control chip appends a 16-bit cyclic redundancy check code to the end of the message to enhance data integrity. The packaged control message is then transmitted to the wireless communication module via DMA. The wireless module completes the over-the-air transmission of the message and sends it to the external information source device. After the message is sent, the main control chip increments the transition period counter by one bit and enters the timed wait for the next cycle, continuing to perform the next round of interpolation calculation and message output until the counter value reaches the set total number of transition cycles. At this point, it indicates that the parameter smooth transition phase has been completed, and the main control chip sets the current interpolation parameter to the new historical parameter value and clears the counter.

[0024] In one example, an ambient light level is collected by an ambient light sensor in a code table, and the median is extracted to obtain a second ambient light level. This second ambient light level is then mapped to the corresponding illuminance level index, including: The main control chip of the code meter periodically reads the first ambient light illuminance from the data register of the ambient light sensor via the digital bus; The first ambient illuminance is written sequentially into a circular buffer queue of a preset length to obtain an illuminance filtering queue. The first ambient illuminance in the illuminance filtering queue is sorted and the median is extracted to obtain the second ambient illuminance. Map the second ambient illuminance to the corresponding illuminance level index.

[0025] In this example, the communication interface configuration between the main control chip and the ambient light sensor is completed at the hardware level, using standard I / O. 2 The C-band digital bus protocol simplifies pin resources and improves stability. The main control chip incorporates interrupt logic to periodically trigger sampling, for example, performing a sensor data read operation every 200 milliseconds. Within each interrupt cycle, the main control chip sends a read command to the sensor's command register, accessing and reading the raw ADC data from two channels of the ambient light sensor, including 16-bit digital values ​​for the infrared and visible light channels. Based on the illuminance conversion coefficient provided by the sensor manufacturer, it calculates a first ambient light illuminance value representing the current ambient brightness. This first ambient light illuminance value is written to a fixed-length circular buffer queue. The circular buffer queue stores multiple recently sampled illuminance data points to eliminate the impact of short-term fluctuations caused by environmental changes or equipment vibration. The buffer queue uses a ring structure design, with a queue length of 5 or 7. When a new sampled value is written, it automatically overwrites the oldest value to maintain a constant length. After each update, the main control chip sorts all illuminance samples in the current buffer and extracts the value in the middle of the sorted sequence as the current filtered second ambient light illuminance. The second ambient illuminance is compared with a set multi-level threshold, and a nested conditional judgment structure is used to determine which specific illuminance level range the value belongs to. For example, five threshold boundaries are set to divide the entire illuminance range into six levels. The main control chip sequentially determines whether the second ambient illuminance is less than the first threshold, whether it is between the two thresholds, or whether it is greater than the highest threshold, and outputs the corresponding illuminance level index value. For example, the index value is set as a discrete integer from 0 to 5 to indicate the current brightness environment level.

[0026] In one example, mapping the second ambient illuminance to the corresponding illuminance level index includes: The illuminance continuous domain is divided into six non-overlapping quantization intervals based on the first, second, third, fourth, and fifth illuminance segmentation thresholds. Hysteresis ratio coefficients are set for the first to the fifth illumination segment thresholds, and the rise and fall judgment thresholds corresponding to each illumination segment threshold are calculated. The code table main control chip compares the second ambient light intensity with the rising and falling judgment thresholds in a nested manner based on the current light level. When the second ambient light intensity exceeds the corresponding rising judgment threshold, the level is incremented. When the second ambient light intensity is lower than the corresponding falling judgment threshold, the level is decremented. Otherwise, the current light level remains unchanged, thus obtaining the light level index.

[0027] The codebook main control chip compares the second ambient illuminance with the rising and falling thresholds sequentially based on the current illuminance level. When the second ambient illuminance exceeds the corresponding rising threshold, a level increment operation is performed; when the second ambient illuminance is below the corresponding falling threshold, a level decrement operation is performed. Otherwise, the current illuminance level remains unchanged, resulting in an illuminance level index. This includes: the codebook main control chip reading the current illuminance level value from the illuminance level status register; determining the corresponding target illuminance segment threshold based on the current illuminance level value; multiplying the target illuminance segment threshold by a preset rising hysteresis coefficient to obtain the rising threshold corresponding to the current level; and multiplying the target illuminance segment threshold by a preset falling hysteresis coefficient to obtain the falling threshold corresponding to the current level. The codebook main control chip then determines the... If the ambient illuminance is greater than the rising threshold, the current illuminance level is incremented by one to obtain a candidate illuminance level value with increasing level. The candidate illuminance level value is then compared with the preset maximum illuminance level threshold, and the smaller value is taken as the updated illuminance level value. If the second ambient illuminance is less than the falling threshold, the current illuminance level is decremented by one to obtain a candidate illuminance level value with decreasing level. The candidate illuminance level value is then compared with zero, and the larger value is taken as the updated illuminance level value. If the second ambient illuminance is neither greater than the rising threshold nor less than the falling threshold, the current illuminance level value remains unchanged as the updated illuminance level value, and the updated illuminance level value is written to the illuminance level status register as the illuminance level index.

[0028] In this example, five pre-defined illumination segment thresholds divide the entire continuous illuminance domain into six non-overlapping quantization intervals. Specifically, the first to fifth illumination segment thresholds are set as TH1, TH2, TH3, TH4, and TH5, respectively, constructing the boundary structures corresponding to the six brightness level intervals. A set of upper and lower hysteresis coefficients is configured for each segment threshold, used to calculate the judgment boundary values ​​of the segment threshold under increasing and decreasing ambient illuminance trends. The increasing hysteresis coefficient is set to 1.15, and the decreasing hysteresis coefficient is set to 0.85. The main control chip calculates the threshold value for each TH5 segment threshold. k Perform multiplication calculations separately to obtain the rising threshold TH. k ×1.15 and the descent threshold TH k× 0.85. Within each control cycle, the code table master control chip reads the current illumination level value from the illumination level status register and determines the illumination segmentation threshold TH corresponding to the target judgment interval based on this value. k The system calculates the rising threshold corresponding to the current level by multiplying the illumination segment threshold by the rising hysteresis coefficient. It then compares the second ambient illuminance with this rising threshold. If the result is "yes," meaning the current ambient brightness exceeds the rising threshold for the current level, a level increment operation is performed. The current illumination level value is incremented by one to obtain the incremented candidate level, which is then compared with a preset maximum level value to take the smaller value as the updated level value, preventing level overflow. If the above judgment is not true, the main control chip multiplies the target threshold by the falling hysteresis coefficient to obtain the falling threshold and checks whether the second ambient illuminance is less than the falling threshold value. If the result is "yes," a level decrement operation is performed, decrementing the current level value by one to obtain the candidate value, which is then compared with 0 to take the larger value as the updated level value, preventing the level value from underflowing to a negative number. If both comparisons are not satisfied, meaning the second ambient illuminance is within the hysteresis window range, the current illumination level remains unchanged. The updated illumination level value is written to the illumination level status register and used as the illumination level index value for the current cycle.

[0029] In one example, the first projection parameter is retrieved from a preset standard projection matrix based on the illumination level index, including: The code table main control chip reads the storage base address of the standard projection matrix from the base address register of the read-only memory, calculates the address offset of the target row based on the product of the illumination level index and the preset row byte length, and adds the storage base address and the address offset to obtain the starting address of the target row. The code table master control chip sequentially reads matrix element data from four consecutive storage addresses: the target row start address, the target row start address plus the first column offset, the target row start address plus the second column offset, and the target row start address plus the third column offset, to obtain four parameter values ​​to be verified. The code table main control chip performs a boundary validity judgment within a preset range on each of the four parameter values ​​to be verified. When all four parameter values ​​to be verified pass the boundary validity judgment, the four parameter values ​​to be verified are used as the first projection parameters. The first projection parameters include the reference display brightness, the reference encoding bit rate, the reference transmission resolution, and the reference refresh frame rate.

[0030] In this example, during the factory manufacturing process, the manually calibrated standard projection matrix is ​​written into a contiguous storage area of ​​the read-only memory (ROM) of the code table main control chip in a preset data format. The standard projection matrix is ​​divided into several rows according to the illumination level. Each row contains four parameters: baseline display brightness (in nits), baseline encoding bitrate (in Kbps), baseline transmission resolution (represented by enumerated values), and baseline refresh frame rate (in fps). Each parameter is stored as a 16-bit unsigned integer, so the total storage length of each row is 8 bytes. During runtime, the main control chip reads the current illumination level index k from the illumination level status register and calculates the address offset of the target row in the ROM by multiplying k by a predefined row length constant (e.g., 8 bytes). It then obtains the storage base address of the starting position of the mapping matrix in the ROM from the base address register and adds the storage base address to the address offset to obtain the starting address of the target row, which is the first storage unit position of the parameter group corresponding to the current illumination level. The main control chip sequentially reads four consecutive 16-bit matrix elements from the target row start address, target row start address +2, target row start address +4, and target row start address +6. These four values ​​constitute the parameter vector to be verified, corresponding to the display brightness value, encoding bitrate value, transmission resolution enumeration value, and refresh frame rate value, respectively. To ensure that these data are not corrupted during storage or that the ROM area has not been illegally modified, the main control chip performs boundary validity checks on each parameter. The brightness parameter is within the range of 50 to 800 nits, the bitrate parameter is between 1000 and 6000 Kbps, the resolution parameter is one of the discrete sets {0, 1, 2}, and the frame rate parameter is limited to three fixed values: 24, 30, or 60 fps. The main control chip compares each parameter with its upper and lower limits for verification. Only when all four parameters meet the boundary constraints is the read data confirmed as a valid configuration, and this set of four-element vectors is set as the first projection parameter for the configuration and output of various image-related modules in the current projection control cycle. If any parameter fails to meet the boundary requirements during the above verification process, the main control chip will consider the ROM matrix data to be abnormal or the illumination index to be out of bounds, and will automatically fall back to the built-in default safety parameter group to ensure the stability of the device operation and the minimum acceptable performance level of the projection display.

[0031] The standard projection matrix is ​​constructed and solidified into read-only memory through offline calibration experiments before the code meter leaves the factory. This includes: using a programmable light source array in a standard darkroom to generate typical lighting environments corresponding to the midpoint values ​​of six quantization intervals; configuring an ambient light sensor to collect the calibrated illuminance value of each typical lighting environment; and under the lighting environment corresponding to each calibrated illuminance value, increasing the display brightness parameter of the projection system by a first step within a preset brightness range, increasing the encoding bitrate parameter by a second step within a preset bitrate range, traversing the transmission resolution parameter in a preset resolution level set, and traversing the refresh frame rate parameter in a preset frame rate level set to obtain multiple parameter combinations; In a simulated cycling environment, users subjectively rated the visibility of multiple parameter combinations and simultaneously measured the system power consumption corresponding to each parameter combination. A weighted comprehensive evaluation index was calculated for each parameter combination. The weighted comprehensive evaluation index is the weighted sum of the normalized value of the visibility score and the inverse of the normalized value of the power consumption. From all parameter combinations corresponding to each calibrated illuminance value, the parameter combination corresponding to the maximum value of the weighted comprehensive evaluation index was selected. The display brightness value, encoding bitrate value, transmission resolution level, and refresh frame rate value of this parameter combination were sequentially filled into the four columns of the corresponding illuminance level row of the standard projection matrix. After completing the matrix element assignment, the standard projection matrix was written to read-only memory and the write protection fuse bit was blown.

[0032] Specifically, when not all four parameter values ​​to be verified pass the boundary validity check, a multi-level degradation parameter selection strategy is implemented, including: the code table main control chip performs boundary validity checks on each of the four parameter values ​​to be verified, counts the number of parameters that fail the boundary validity check to obtain an invalid parameter count, and records the column index position corresponding to each invalid parameter value; when the invalid parameter count is equal to one, the corresponding spare parameter value is read from the preset spare parameter mapping table according to the illumination level index and column index position to replace the invalid parameter value, and the four replaced parameter values ​​are used as the first projection parameters; when the invalid parameter count is greater than one... When the value is less than four, the matrix elements of the previous and next illumination level rows adjacent to the illumination level index are read from the standard projection matrix. The corresponding column elements of the adjacent level rows are weighted and averaged to obtain the interpolation repair parameter value. The interpolation repair parameter value is used to replace all invalid parameter values, and the four replaced parameter values ​​are used as the first projection parameters. When the invalid parameter count value is equal to four, it is determined that the current row of the standard projection matrix is ​​corrupted. The code table main control chip reads four preset security default parameter values ​​from the preset security default parameter register as the first projection parameters and sets the matrix abnormality flag to trigger a system alarm. The code table main control chip records the invalid parameter count value and column index position to the error log buffer. When matrix element verification fails for multiple consecutive control cycles, it is determined that there is a hardware fault in the read-only memory and the protective frequency reduction mode of the projection system is started.

[0033] In one example, the link quality metrics and device load metrics between the code table and the external information source device are calculated, and the baseline coding bitrate and baseline refresh frame rate in the first projection parameters are corrected accordingly to obtain the second projection parameters, including: The code table master control chip reads the first received signal strength value from the signal strength register of the wireless module through the serial bus, adds a preset negative offset compensation value to the first received signal strength value to obtain the second received signal strength value, and then divides the second received signal strength value by a preset normalization divisor to obtain the link quality index. The code table main control chip reads its own processor's utilization status register to obtain the processor utilization rate, and divides the processor utilization rate by a percentage base to obtain the device load index; The baseline coding bitrate and baseline refresh frame rate in the first projection parameters are corrected based on the link quality index and the device load index to obtain the second projection parameters.

[0034] In this example, the code table master control chip constructs a serial communication path, establishes a master-slave communication relationship with the wireless module based on the SPI bus, and triggers the status reading process periodically. Within each control cycle, the master control chip sends a read command to the wireless module and accesses its internal signal strength register to obtain the first received signal strength value at the current moment. This value, in dBm, inversely maps the attenuation level of the transmission link; for example, a common read value is between -85dBm and -45dBm. Since the wireless signal is affected by factors such as antenna directivity and enclosure obstruction, a negative offset compensation value, such as +5dBm, is added to the first received signal strength value through empirical measurement or hardware calibration to obtain a corrected second received signal strength value. The second received signal strength value is then linearly scaled with a preset normalization divisor; for example, the range [-90dBm, -40dBm] is mapped to a floating-point value range between [0,1]. For instance, the corrected value is added to 90 and then divided by 50, i.e., Q = (RSSI + 90) / 50, to obtain the link quality index representing the current health of the transmission link. Simultaneously, the code table master control chip reads its own processor's occupancy status register to obtain the current processor occupancy value, expressed in percentage format, such as 78%. The chip divides this value by the percentage base of 100 to obtain the standardized device load index D ∈ [0,1]. Based on the link quality index Q and the device load index D, the original encoding bitrate and refresh frame rate in the first projection parameters are corrected item by item. The link quality index is used to dynamically adjust the encoding bitrate. When the Q value is high (e.g., greater than 0.7), the base bitrate remains unchanged. When the Q value decreases, the bitrate is reduced through a linear decay function to adapt to the bandwidth-constrained link environment and avoid packet loss due to excessively high data rates. The device load index is used to determine the decoding processing capability of the code table end. When the D value is less than a certain threshold (e.g., 0.6), the frame rate remains unchanged. When the D value rises to close to 1.0, a linear decay strategy is used to reduce the frame rate to alleviate decoding load and power consumption pressure. The bitrate value and frame rate value after dual index correction, along with the uncorrected display brightness and resolution, form the updated second projection parameters.

[0035] Before assembling the target encoding bitrate, target refresh frame rate, and the baseline display brightness and baseline transmission resolution from the first projection parameters to obtain the second projection parameters, the target encoding bitrate and baseline transmission resolution are collaboratively optimized and corrected based on the parameter coupling relationship. This includes: the code table main control chip calculates the bitrate correction ratio between the target encoding bitrate and the baseline encoding bitrate, determines whether the bitrate correction ratio is less than a preset bitrate reduction threshold, and when the bitrate correction ratio is less than the preset bitrate reduction threshold, it determines that the link quality has decreased and triggers resolution collaborative degradation; the code table main control chip determines whether there is room for degradation based on the current level of the baseline transmission resolution, and when the baseline transmission resolution level is greater than the lowest resolution level, it reduces the baseline transmission resolution by one level to obtain the collaboratively optimized transmission resolution, and calculates the resolution degradation compensation system based on the ratio of the total number of pixels corresponding to the collaboratively optimized transmission resolution to the total number of pixels corresponding to the baseline transmission resolution. The target encoding bitrate is multiplied by the reciprocal of the resolution degradation compensation coefficient to obtain the target encoding bitrate after bitrate-resolution co-optimization. The reciprocal of the resolution degradation compensation coefficient is greater than the unit value, which increases the encoding bitrate allocation per unit pixel to maintain image quality when the resolution is reduced. The code table main control chip calculates the frame rate correction ratio between the target refresh frame rate and the reference refresh frame rate. When the frame rate correction ratio is less than the preset frame rate reduction threshold and the bitrate correction ratio is greater than the preset bitrate sufficiency threshold, it is determined that the device load is high but the link bandwidth is sufficient. The target encoding bitrate after bitrate-resolution co-optimization is multiplied by the preset bandwidth utilization compensation coefficient to obtain the final target encoding bitrate. The preset bandwidth utilization compensation coefficient is less than the unit value, so the bitrate is reduced to match the reduced frame rate and avoid bandwidth waste. The final target encoding bitrate, target refresh frame rate, co-optimized transmission resolution, and reference display brightness in the first projection parameters are assembled to obtain the second projection parameters.

[0036] In one example, the baseline coding bitrate and baseline refresh frame rate in the first projection parameters are corrected based on link quality metrics and device load metrics, respectively, to obtain the second projection parameters, including: The link correction coefficient is determined based on the link quality index and the first preset threshold. The target coding rate is obtained by multiplying the baseline coding rate and the link correction coefficient in the first projection parameters. The equipment load correction coefficient is determined based on the equipment load index and the second preset threshold. The target refresh rate is obtained by multiplying the baseline refresh rate in the first projection parameter with the device load correction coefficient. The second projection parameter is obtained by assembling the target encoding bitrate, target refresh frame rate, and the reference display brightness and reference transmission resolution from the first projection parameter.

[0037] In this example, the link quality index Q is compared with a first preset threshold T1 (e.g., set to 0.7). If Q is greater than or equal to T1, the current wireless link quality is considered good, and the main control chip sets the link correction coefficient to 1.0, keeping the baseline coding bitrate unchanged. When Q is less than T1, it indicates that the link signal is weak or there is potential interference. To avoid the risk of packet loss at high bitrates, the main control chip calculates the link correction coefficient based on the value of Q using a continuous linear decreasing function. The linear decreasing function starts at Q=T1 (link correction coefficient = 1.0) and ends at Q=0 (link correction coefficient = 0.5), forming an adjustment mechanism from full bitrate to the minimum tolerable bitrate. The target coding bitrate is calculated by multiplying the baseline coding bitrate in the first projection parameters with the link correction coefficient, reflecting the most suitable video coding rate configuration under the current network conditions. The device load index D is compared with the second preset threshold T2 (e.g., set to 0.6). If D is less than or equal to T2, it indicates that the code table processing capacity still has margin, and the main control chip sets the device load correction coefficient to 1.0 to maintain the original frame rate. If D is higher than T2, it indicates that the code table load is approaching saturation. To prevent overload or abnormal system overheating, the main control chip uses a segmented linear decay function to adaptively adjust the frame rate. The segmented linear decay function is designed so that as D rises from T2 to 1.0, the load correction coefficient linearly decreases from 1.0 to 0.5, gradually reducing the high frame rate to a medium or low frame rate. The reference refresh frame rate is multiplied by the load correction coefficient to calculate the target refresh frame rate, which is the dynamic frame rate output value that optimally balances decoding burden and smoothness under the current system state. The target encoding bitrate, the target refresh frame rate, and the two reference static parameters that were not corrected in the first projection parameters—namely, the reference display brightness and the reference transmission resolution—are assembled into a four-element parameter vector, which is the second projection parameter.

[0038] In one example, the link correction coefficient is determined based on the link quality metric and a first preset threshold, including: When the link quality index is greater than or equal to the first preset threshold, the link correction coefficient is set to a unit value; When the link quality index is less than the first preset threshold, the link quality index is divided by the first preset threshold and linearly calculated with the preset first attenuation parameter to obtain the link correction coefficient.

[0039] In this example, the link quality index Q is compared with a preset first threshold T1, which is set to 0.7, as a benchmark for determining whether the current wireless link is stable. If the value of Q is greater than or equal to T1, it indicates that the current wireless signal strength is good and the data channel conditions for carrying high bit rate transmission are met. The main control chip directly sets the link correction coefficient to a unit value of 1.0. At this time, the baseline coding bit rate does not need to be adjusted and is directly used for screen projection parameter output, thereby maximizing coding quality and image detail preservation. If the link quality index Q is less than T1, it indicates that the current wireless transmission link is limited, with adverse factors such as signal attenuation, increased interference, or increased noise figure. To avoid packet loss or latency accumulation due to excessively high bit rate, the main control chip appropriately reduces the coding bit rate. Dividing the link quality index Q by the first threshold T1 yields a normalized ratio, which is between 0 and 1. As Q approaches T1, its value approaches 1, and as Q decreases to 0, its value approaches 0. The normalized ratio is linearly calculated with the first attenuation parameter α, where α is a defined minimum correction lower limit, such as 0.5, used to limit the minimum allowable correction strength under worst-case link conditions. The linear calculation form is link correction coefficient = α + (1 - α) × normalized ratio, constructing an increasing mapping curve from link correction coefficient = α when Q=0 to link correction coefficient = 1.0 when Q=T1. This allows for timely reduction of the bit rate to adapt to the actual capacity of the transmission channel when the link deteriorates, and automatic increase of the correction coefficient as the link gradually recovers, ultimately restoring to the full bit rate level.

[0040] In one example, the equipment load correction factor is determined based on the equipment load index and a second preset threshold, including: When the equipment load index is less than or equal to the second preset threshold, the equipment load correction coefficient is set to a unit value; When the equipment load index is greater than the second preset threshold, the difference between the equipment load index and the second preset threshold is divided by the preset load range and linearly calculated with the preset attenuation amplitude to obtain the equipment load correction coefficient.

[0041] In this example, the device load index D is compared with a preset second threshold T2, which is set to 0.6 to divide the device load state into normal and restricted ranges. If D is less than or equal to T2, it indicates that the external information source device still has sufficient decoding capability and buffer capacity. The main control chip does not need to perform any load reduction operation and directly sets the device load correction coefficient to a unit value of 1.0, keeping the baseline refresh frame rate in the first projection parameter unchanged. When D is detected to be greater than T2, that is, the device is in an overload critical state or the load has increased significantly, the main control chip starts the load correction function to moderately reduce the output frame rate, alleviating the decoding pressure and heat dissipation burden at the code table end. The difference between the current device load index and the preset threshold ΔD = D - T2 is calculated. ΔD is divided by the preset load linear response range R_D, which is the width of the effective response range defined by the system. For example, setting it to 0.4 means that the linear correction range is from T2=0.6 to 1.0. The ΔD / R_D is multiplied by the set maximum attenuation amplitude A_D, where A_D is the unit value minus the minimum acceptable frame rate correction factor. For example, A_D = 0.5 means that the frame rate can be reduced to at least 50% of the original value. The main control chip uses the unit value minus this product as the device load correction factor, i.e., 1.0 - A_D × ((D - T2) / R_D). This results in a lower frame rate correction factor when the load is higher, and the output automatically and gradually recovers to full frame rate output as the load decreases.

[0042] Before correcting the baseline encoding bitrate and baseline refresh frame rate in the first projection parameters based on link quality indicators and device load indicators, respectively, the link quality indicators and device load indicators undergo historical sequence volatility assessment and dynamic adjustment of the correction trigger threshold. This includes: the code table main control chip maintains historical sequences of link quality indicators and device load indicators with a preset sequence length; appending the currently collected link quality indicators and device load indicators to the end of their respective historical sequences and removing the oldest data at the beginning of the sequence; calculating the sequence mean and sequence variance of the historical sequences of link quality indicators to obtain link quality volatility characteristic values, and calculating the sequence mean and sequence variance of the historical sequences of device load indicators to obtain device load volatility characteristic values; the code table main control chip determines the link status stability level based on the link quality volatility characteristic values; when the link quality volatility characteristic value is less than the first volatility threshold, it is determined to be a stable link state, and the first preset threshold is reduced by a preset first adjustment amount to obtain the dynamic link correction trigger threshold. When the quality fluctuation characteristic value is greater than the second fluctuation threshold, it is determined to be a fluctuating link state, and the first preset threshold is increased by a preset second adjustment amount to obtain the dynamic link correction trigger threshold; otherwise, the first preset threshold remains unchanged as the dynamic link correction trigger threshold. The codebook main control chip determines the device load stability level based on the device load fluctuation characteristic value. When the device load fluctuation characteristic value is less than the third fluctuation threshold, it is determined to be a stable load state, and the second preset threshold is increased by a preset third adjustment amount to obtain the dynamic device correction trigger threshold. When the device load fluctuation characteristic value is greater than the fourth fluctuation threshold, it is determined to be a fluctuating load state, and the second preset threshold is decreased by a preset fourth adjustment amount to obtain the dynamic device correction trigger threshold; otherwise, the second preset threshold remains unchanged as the dynamic device correction trigger threshold. The dynamic link correction trigger threshold is used to replace the first preset threshold to judge the link quality index and calculate the link correction coefficient. The dynamic device correction trigger threshold is used to replace the second preset threshold to judge the device load index and calculate the device load correction coefficient.

[0043] In one example, the projection parameters output from the previous control cycle and the second projection parameters are linearly interpolated and smoothed within a preset number of transition cycles, and then encapsulated into a projection control message and sent to an external information source device, including: The code table main control chip initializes the transition cycle counter to zero and reads the projection parameters output from the previous control cycle from the parameter history cache register; The interpolation weight coefficient is obtained by dividing the current count value of the transition cycle counter by the preset number of transition cycles. The difference between the projection parameters output in the previous control cycle and the second projection parameters is multiplied by the interpolation weight coefficient and then added to the projection parameters output in the previous control cycle to obtain the interpolated projection parameters for the current cycle. The main control chip of the code table encodes the interpolated projection parameters of the current period sequentially and encapsulates them with a cyclic redundancy check code into a projection control message, which is then sent to the external information source device through the wireless module. The transition period counter is incremented until the preset number of transition periods is reached.

[0044] In this example, the main control chip initializes its internal transition cycle counter to zero and reads the projection parameter vector output from the previous control cycle from the parameter history cache register. This vector contains values ​​for four dimensions: display brightness, encoding bitrate, transmission resolution, and refresh rate, serving as the interpolation starting point. The chip calculates the weight coefficient α corresponding to the current interpolation cycle by dividing the current transition cycle counter value n by the set total number of transition cycles N, i.e., α = n / N. The weight coefficient controls the parameter offset within the current cycle. As the cycle progresses, the weight coefficient gradually increases from 0 to 1, achieving a linear transition from the old parameters to the target parameters. The main control chip uses the weight coefficient to perform component-level interpolation on the parameters. It multiplies the difference vector between the second projection parameter and the previous cycle parameter by α, and then adds it item by item to the previous cycle parameter vector to obtain the interpolated projection parameters used to control the output in the current cycle. Brightness, bitrate, and frame rate are continuous variables that can be directly interpolated. Resolution is used as a discrete enumerated variable to set threshold switching rules. For example, when α is less than 0.5, the original resolution is maintained; when α is greater than or equal to 0.5, the target resolution is switched. After calculating the interpolated projection parameters for the current period, the main control chip enters the encoding stage. It encodes the four parameter values ​​sequentially into a data packet body according to the Type-Length-Value format defined by the communication protocol. Brightness is stored in 2 bytes, bitrate in 4 bytes, and resolution and frame rate are each enumerated and encoded using 1 byte. The main control chip then calls a cyclic redundancy check (CRC-16) generation module to calculate the checksum for the entire data segment and appends the checksum to the end of the packet to form the projection control message. The main control chip transmits the projection control message to the external information source device through the wireless module's transmission interface, completing the parameter control synchronization for the current period. After the message is transmitted, the main control chip increments the transition period counter by 1 and enters the waiting timer state for the next period until the counter value equals the preset number of transition periods N. At this point, the main control chip confirms the end of the interpolation process and writes the second projection parameter into the parameter history cache register as a new reference.

[0045] The preset transition cycle number is adaptively adjusted based on the parameter change range between the projection parameters output in the previous control cycle and the second projection parameters. This includes: the code meter main control chip calculating the absolute differences between the second projection parameters and the projection parameters output in the previous control cycle in four parameter dimensions: display brightness, encoding bitrate, transmission resolution, and refresh frame rate, to obtain the absolute values ​​of the four parameter changes; normalizing the absolute values ​​of the four parameter changes by dividing them by the preset maximum change range of the corresponding parameters to obtain the normalized values ​​of the four parameter change rates, and extracting the maximum value from the normalized values ​​of the four parameter change rates as the comprehensive parameter change rate; the code meter main control chip then adjusts the transition cycle number based on the comprehensive parameter change rate. The range of the combined parameter change rate determines the number of adaptive transition cycles. When the combined parameter change rate is less than the first change rate threshold, the number of adaptive transition cycles is set to the minimum transition cycle value. When the combined parameter change rate is greater than the second change rate threshold, the number of adaptive transition cycles is set to the maximum transition cycle value. When the combined parameter change rate is between the first and second change rate thresholds, the number of adaptive transition cycles is calculated by linear interpolation. The code table main control chip uses the number of adaptive transition cycles to replace the fixed preset transition cycle number and performs linear interpolation smoothing processing between the projection parameters output in the previous control cycle and the second projection parameters within the number of adaptive transition cycles.

[0046] The codebook master control chip reads the first received signal strength value from the signal strength register of the wireless module and its own processor utilization status register via a serial bus. A timestamp synchronization mechanism ensures timely data acquisition. This includes: the codebook master control chip initiates a dual-thread parallel acquisition task; the first acquisition thread initiates a read request to the signal strength register of the wireless module via the serial bus and records the first acquisition timestamp; the second acquisition thread reads its own processor utilization status register and records the second acquisition timestamp; after receiving the first received signal strength value returned by the wireless module, the first acquisition thread calculates the time difference between the first acquisition timestamp and the current system clock to obtain the first acquisition delay; the second acquisition thread, upon receiving the first received signal strength value, calculates the time difference between the first acquisition timestamp and the current system clock to obtain the first acquisition delay; the second acquisition thread, upon receiving the first received signal strength value, calculates the time difference between the first acquisition timestamp and the current system clock to obtain the first acquisition delay. After obtaining the processor utilization rate value, the time difference between the second acquisition timestamp and the current system clock is calculated to obtain the second acquisition delay. The code table main control chip determines whether both the first acquisition delay and the second acquisition delay are less than the preset acquisition effective time window. If the determination result is yes, the time-varying state parameters of this acquisition are discarded and re-acquisition is triggered. If the determination result is yes, the absolute difference between the first acquisition timestamp and the second acquisition timestamp is calculated to obtain the acquisition time deviation. When the acquisition time deviation is greater than the preset synchronization time threshold, the time deviation compensation correction is applied to the time-varying state parameters with earlier acquisition times. The time-varying state parameters are weighted and averaged with their historical values ​​in the previous control cycle to obtain the synchronization state parameter value after time alignment.

[0047] Reference Figure 2 This embodiment provides a codebook projection control system based on ambient light sensing, including: Acquisition module 1 is used to acquire the first ambient light illuminance through the ambient light sensor in the code table and extract the median to obtain the second ambient light illuminance, and map the second ambient light illuminance to the corresponding light level index; Reading module 2 is used to look up the corresponding first projection parameter from the preset standard projection matrix according to the illumination level index; Correction module 3 is used to calculate the link quality index and device load index between the code table and the external information source device, and correct the base coding bit rate and base refresh frame rate in the first projection parameters to obtain the second projection parameters. The sending module 4 is used to interpolate the projection parameters output in the previous control cycle and the second projection parameters within a preset number of transition cycles, encapsulate them into a projection control message, and send it to an external information source device.

[0048] In this embodiment, the specific implementation of each unit in the above system embodiment is described in the above method embodiment, and will not be repeated here.

[0049] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, system, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, system, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, system, article, or method that includes that element.

[0050] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for controlling the projection of a computer clock based on ambient light sensing, characterized in that, include: The first ambient light intensity is collected by the ambient light sensor in the code table and the median is extracted to obtain the second ambient light intensity. The second ambient light intensity is then mapped to the corresponding light level index. The corresponding first projection parameter is retrieved from the preset standard projection matrix based on the illumination level index; The link quality index and device load index between the code table and the external information source device are calculated, and the baseline coding bit rate and baseline refresh frame rate in the first projection parameters are corrected to obtain the second projection parameters. The projection parameters output in the previous control cycle and the second projection parameters are interpolated within a preset number of transition cycles, encapsulated into a projection control message, and sent to an external information source device.

2. The method for controlling the projection of a code table based on ambient light sensing according to claim 1, characterized in that, The step of collecting a first ambient light intensity and extracting the median from the ambient light sensor in the code table to obtain a second ambient light intensity, and mapping the second ambient light intensity to the corresponding light level index, includes: The main control chip of the code meter periodically reads the first ambient light illuminance from the data register of the ambient light sensor via the digital bus; The first ambient illuminance is sequentially written into a circular buffer queue of a preset length to obtain an illuminance filtering queue. The first ambient illuminance in the illuminance filtering queue is sorted and the median is extracted to obtain the second ambient illuminance. Map the second ambient illuminance to the corresponding illuminance level index.

3. The method for controlling the projection of a code table based on ambient light sensing according to claim 2, characterized in that, The step of mapping the second ambient illuminance to the corresponding illuminance level index includes: The illuminance continuous domain is divided into six non-overlapping quantization intervals based on the first, second, third, fourth, and fifth illuminance segmentation thresholds. Hysteresis ratio coefficients are set for the first to the fifth illumination segment thresholds, and the rise and fall judgment thresholds corresponding to each illumination segment threshold are calculated. The code table main control chip compares the second ambient light intensity with the rising and falling judgment thresholds in a nested manner based on the current light level. When the second ambient light intensity exceeds the corresponding rising judgment threshold, the level increment operation is performed. When the second ambient light intensity is lower than the corresponding falling judgment threshold, the level decrement operation is performed. Otherwise, the current light level remains unchanged, thus obtaining the light level index.

4. The method for controlling the projection of a code table based on ambient light sensing according to claim 1, characterized in that, The step of retrieving the corresponding first projection parameter from a preset standard projection matrix based on the illumination level index includes: The code table main control chip reads the storage base address of the standard projection matrix from the base address register of the read-only memory, calculates the address offset of the target row according to the product of the illumination level index and the preset row byte length, and adds the storage base address and the address offset to obtain the starting address of the target row. The code table master control chip sequentially reads matrix element data from four consecutive storage addresses: the target row start address, the target row start address plus the first column offset, the target row start address plus the second column offset, and the target row start address plus the third column offset, to obtain four parameter values ​​to be verified. The code table main control chip performs a boundary validity judgment within a preset range on the four parameter values ​​to be verified. When all four parameter values ​​to be verified pass the boundary validity judgment, the four parameter values ​​to be verified are used as the first projection parameters. The first projection parameters include the reference display brightness, the reference encoding bit rate, the reference transmission resolution, and the reference refresh frame rate.

5. The method for controlling the projection of a code table based on ambient light sensing according to claim 1, characterized in that, The link quality index and device load index between the calculated code table and the external information source device are used to correct the baseline coding bitrate and baseline refresh frame rate in the first projection parameters, respectively, to obtain the second projection parameters, including: The code table master control chip reads the first received signal strength value from the signal strength register of the wireless module through the serial bus, adds a preset negative offset compensation value to the first received signal strength value to obtain the second received signal strength value, and then divides the second received signal strength value by a preset normalization divisor to obtain the link quality index. The code table main control chip reads its own processor's utilization status register to obtain the processor utilization rate, and divides the processor utilization rate by a percentage base to obtain the device load index; The baseline encoding bitrate and baseline refresh frame rate in the first projection parameters are corrected based on the link quality index and the device load index, respectively, to obtain the second projection parameters.

6. The method for controlling the projection of a code table based on ambient light sensing according to claim 5, characterized in that, The second projection parameters are obtained by correcting the baseline coding bitrate and baseline refresh frame rate in the first projection parameters according to the link quality index and the device load index, respectively, including: The link correction coefficient is determined based on the link quality index and the first preset threshold. The target coding rate is obtained by multiplying the baseline coding rate in the first projection parameters with the link correction coefficient. The equipment load correction coefficient is determined based on the equipment load index and the second preset threshold. The target refresh rate is obtained by multiplying the baseline refresh rate in the first projection parameters with the device load correction coefficient. The target encoding bitrate, the target refresh frame rate, and the reference display brightness and reference transmission resolution in the first projection parameters are assembled to obtain the second projection parameters.

7. The method for controlling the projection of a code table based on ambient light sensing according to claim 6, characterized in that, The step of determining the link correction coefficient based on the link quality index and the first preset threshold includes: When the link quality index is greater than or equal to the first preset threshold, the link correction coefficient is set to a unit value; When the link quality index is less than the first preset threshold, the link quality index is divided by the first preset threshold and linearly calculated with the preset first attenuation parameter to obtain the link correction coefficient.

8. The method for controlling the projection of a code table based on ambient light sensing according to claim 6, characterized in that, The step of determining the equipment load correction coefficient based on the equipment load index and the second preset threshold includes: When the equipment load index is less than or equal to the second preset threshold, the equipment load correction coefficient is set to a unit value. When the equipment load index is greater than the second preset threshold, the difference between the equipment load index and the second preset threshold is divided by the preset load range and linearly calculated with the preset attenuation amplitude to obtain the equipment load correction coefficient.

9. The method for controlling the projection of a code table based on ambient light sensing according to claim 1, characterized in that, The step of performing linear interpolation smoothing on the projection parameters output in the previous control cycle and the second projection parameters within a preset number of transition cycles, and then encapsulating them into a projection control message for transmission to an external information source device, includes: The code table main control chip initializes the transition cycle counter to zero and reads the projection parameters output from the previous control cycle from the parameter history cache register; The interpolation weighting coefficient is obtained by dividing the current count value of the transition period counter by the preset number of transition periods. The difference between the projection parameters output in the previous control cycle and the second projection parameters is multiplied by the interpolation weight coefficient and then added to the projection parameters output in the previous control cycle to obtain the interpolation projection parameters for the current cycle. The code table main control chip sequentially encodes the interpolated projection parameters of the current period and adds a cyclic redundancy check code to encapsulate them into a projection control message, which is then sent to an external information source device through a wireless module. The transition period counter is incremented until the preset number of transition periods is reached.

10. A clock display projection control system based on ambient light sensing, characterized in that, The steps for implementing the ambient light sensing-based code table projection control method according to any one of claims 1 to 9 include: The acquisition module is used to acquire the first ambient light illuminance through the ambient light sensor in the code table and extract the median to obtain the second ambient light illuminance, and map the second ambient light illuminance to the corresponding light level index. The reading module is used to look up the corresponding first projection parameter from the preset standard projection matrix according to the illumination level index; The correction module is used to calculate the link quality index and device load index between the code table and the external information source device, and correct the base coding bit rate and base refresh frame rate in the first projection parameters to obtain the second projection parameters. The sending module is used to interpolate the projection parameters output in the previous control cycle and the second projection parameters within a preset number of transition cycles, encapsulate them into a projection control message, and send it to an external information source device.

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