Design And Implementation Of A Rotationg LED Display System

LED, as known as Light Emitting Diode, leads the pace of social development, this illumination method with long life, high luminous efficiency, no radiation and low power consumption, appears with high speed in various kinds of LED display boards, publicity column and large screen in the streets. After accustomed to large and small square-shaped LED display device, a novel rotating LED display based on the persistence of vision effect gradually appeared in our vision.This rotating LED display has many incomparable advantages, such as low cost, low power, small space and could be installed on any object with a rotating property and does not take up too much volume.This paper analyzes the structure and algorithm of rotating LED display, including the core algorithm such as full-color LED color mixing, synchronization of multiple display arms, self-adaptivation of speed and PWM dimming method.Qt is a Cross-platform C++ graphical user interface application framework. According to the algorithm, this paper developed in line with the requirements of the rotation full-color LED display modulo software using the Qt framework, to obtain the desired polar LED dot matrix color data.On this basis, in order to meet the requirements of software complexity and realtime property, we chose the embedded real-time RT-Thread operating system which develop by Chinese team with functions of thread management and scheduling; based on the algorithms, after writing user programs and drivers in the RT-Thread Architecture, we can process the image data and control LED light. All embedded software was coded with Eclipse, and debugged with the IAR for Eclipse plug-in.In order to meet the performance requirements, but also in order to support RTThread, this paper chose the STM32 series MCU as the master chip, STM32 series MCU is based on ARM® Cortex ?-M3 32-bit RISC core, and has the maximum frequency of 72 MHz with up to 512 K of Flash and 64 K of SRAM. Peripheral hardware module includes a multi-channel full-color LED driver chip, Bluetooth modules, power supply modules, Hall sensor module. All schematic drawing and PCB layout was accomplished using Altium Designer.This paper researched and designed the hardware and software of the entire rotating LED display system, completed the task and achieved the desired goal.Finally, with the results and demonstration showing at the end of this paper, it summarized current results and analyzed the shortcomings with improving suggestion.