introduction
The LED dot matrix display is a display device composed of LED arrays, which has the advantages of high brightness, low operating voltage, low power consumption, simple driving, long life, impact resistance and stable performance. As an electronic advertisement type of information publishing method, it is mainly used to publish various concise announcement information such as characters, Chinese characters, graphics, and the like. At present, LED dot matrix displays are developing in the direction of higher luminance, uniformity of illumination, luminous density and weather resistance. As the requirements for display effects increase, so does the requirement for a dot matrix display control system.
The high-brightness LED dot matrix display module can be controlled by an embedded microprocessor to form a separate system for displaying fixed information, such as bank deposit interest rate, and remotely communicating with a microcomputer to form a host computer. The dot matrix display control system [1] that stores and transmits the display content basically adopts this method in the case where it is required to update the display information in real time and requires a large display storage space. In the current dot matrix display control system, most of them still use RS232 interface to communicate with the host computer [2-7], which brings inconvenience to many computer connections without serial port, and the selection of inline devices is still more. The produced LED dot matrix display technology is backward, the failure rate is high, and the power consumption is large. If chip devices and large-scale programmable devices are used to replace conventional chips, the production process and screen performance can be greatly improved, the faults can be minimized, and the power consumption of the screen body can be greatly reduced.
The embedded PIC series MCU is a product of Microchip. Its CPU adopts RISC structure and adopts Harvard dual bus structure. Its outstanding features are small size, low power consumption, high reliability, fast running speed, direct input and output drive capability. Great advantages, more flexible than the traditional 51 MCU, very suitable for the control system design of LED dot matrix display.
This paper is based on the embedded PIC microcontroller to complete the design and implementation of a 128×16 LED dot matrix display control system. The system uses the miniUSB serial communication interface to connect with the host computer, which can easily receive the display information transmitted by the host computer; Devices and programmable devices increase system performance and reduce system power consumption. Through testing, the system has stable performance and simple operation. It can be applied to many fields after proper expansion, and has good promotion value.
1 system hardware design
The dot matrix control system is composed of a host computer, a display controller, a dot matrix display driving chip, an LED dot matrix display and the like, and the overall design side
The case is shown in Figure 1.
