The dynamic refresh mechanism of an arrow dot matrix light block display achieves smooth display by leveraging the persistence of vision in the human eye. This involves rapidly switching display images and precisely controlling the refresh rate. Essentially, this type of display uses a multiplexed dot matrix structure, such as the common 8×8 or 16×16 dot matrix. Each LED acts as an independent pixel, and its on/off state is controlled by row and column scanning technology. The smoothness of its dynamic refresh depends on hardware circuit design, optimized driving algorithms, and precise control of the refresh rate.
At the hardware level, row and column scanning is fundamental. Taking a common cathode dot matrix as an example, all rows are connected to the anode (high-level drive), and all columns are connected to the cathode (low-level conduction). By rapidly switching the row selection signal, the corresponding columns of LEDs in each row are illuminated sequentially. For example, in an 8×8 dot matrix, only 16 pins (8 rows + 8 columns) are needed to control 64 LEDs. During scanning, only one row is activated at a time, and the on/off state of each column in that row is controlled according to the displayed data before switching to the next row. This process needs to be completed in a very short time. If the refresh rate is below 50Hz, the human eye will perceive flicker; however, when it reaches or exceeds this frequency, the persistence of vision will create a smooth and continuous dynamic effect.
Optimizing the driving algorithm is key to improving smoothness. Traditional static displays require an independent control pin for each light block, resulting in high resource consumption and difficulty in implementing complex animations. Dynamic scanning, on the other hand, reduces data processing time by using time-division multiplexing of pins combined with efficient driving algorithms. For example, using a high-performance LED driver chip (such as the MAX7219), it can communicate with the main controller via an SPI interface to automatically complete row and column scanning, refresh, and brightness adjustment. The main controller only needs to send display data commands, eliminating the need for manual control of each row's on/off state, thus reducing CPU load and ensuring that animation logic and refresh are synchronized. Furthermore, double buffering technology can further optimize performance: the next frame's data is calculated in the background buffer and then exchanged with the front buffer, avoiding screen tearing or flickering.
Precise control of the refresh rate directly affects the display effect. A refresh rate that is too low will cause stuttering, while a refresh rate that is too high may result in dropped frames due to hardware performance limitations. In practical design, the refresh strategy needs to be adjusted based on the dot matrix size and the main control performance. For example, in an 8×8 dot matrix, if the main control uses a timer interrupt to drive scanning, processing one row of data per interrupt, the refresh cycle for the entire screen is the number of rows multiplied by the interrupt interval. If the interrupt interval is set to 1.25ms, the refresh rate of the 8-row dot matrix is 1000ms/(8×1.25ms) = 100Hz, far exceeding the human eye's perception threshold, achieving a flicker-free dynamic effect. For more complex 16×16 dot matrices, the refresh rate can be kept stable above 60Hz by optimizing the interrupt logic or using hardware acceleration.
The method of generating dynamic content also affects smoothness. Simple animations (such as arrows moving left and right) can be achieved by pre-storing frame data and switching it periodically; complex animations (such as sine waves and spirals) require real-time calculation of each frame's data using mathematical formulas. For example, when generating a wave curve using a sine function, the main control needs to calculate the on/off state of each light block based on the current frame index and quickly update it to the driver chip. This process requires balancing computational complexity and refresh rate to avoid screen stuttering due to data processing delays.
Anti-interference design and power supply stability are equally crucial. During PCB routing, signal transmission delays and electromagnetic interference must be minimized to ensure synchronized row and column scanning signals. The power module must provide a stable voltage to prevent fluctuations in light block brightness from affecting display quality. For example, using multi-mode power supply (such as battery/Type-C/DC) can adapt to different scenario requirements, while power filtering circuits can suppress ripple and improve system stability.
From an application perspective, the smooth dynamic effects of arrow dot matrix light block displays have been widely used in industrial equipment status monitoring, public information indication, and stage backdrops. For example, traffic lights use dynamic arrows to indicate driving directions, and their smoothness directly affects driving safety; outdoor billboards use scrolling text to attract attention, and the refresh rate must balance visual appeal and energy consumption. In the future, with the integration of IoT and AI technologies, arrow dot matrix light block displays will support intelligent interactive functions such as remote control and music visualization. The dynamic refresh mechanism needs further optimization to adapt to higher resolutions and more complex animation requirements.
