Interpretation of the circuit design scheme of 51 single-chip LED system

“A rotating LED Display developed based on the principle of persistence of vision when rotating the LED display. It installs 16 LED light-emitting devices on a carrier with a certain rotation speed, and each LED light-emitting tube is arranged in a straight line at equal intervals. With the acceleration of the rotation speed, under the precise timing control of the computer software, the preset text is continuously scanned. Patterns etc.

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Introduction: Rotating LED display is a new type of display that realizes graphic display by synchronously controlling the position and lighting state of light-emitting diodes. It has a novel structure, low cost, and a viewing angle of 360°.

A rotating LED display developed based on the principle of persistence of vision when rotating the LED display. It installs 16 LED light-emitting devices on a carrier with a certain rotation speed, and each LED light-emitting tube is arranged in a straight line at equal intervals. With the acceleration of the rotation speed, under the precise timing control of the computer software, the preset text is continuously scanned. Patterns etc. Use an optocoupler (U-shaped groove infrared pair tube) as the positioning sensor. When rotating for one revolution, the light barrier will block the light source, and the collector of the photosensitive transistor will output high level. When it leaves the light barrier, the collector will output low level again , So as to give the MCU a falling edge transition model, generate an interrupt, and update the display. For the power supply part, because the whole device is rotating continuously at high speed, we made a simple brush device, which turns 220V AC power into 12V AC power through a transformer, and then changes it by a bridge rectifier circuit and a filter circuit. In order to smooth the DC power, finally output the 5V DC power supply we need through the 7805 chip, and connect the power supply to the single-chip microcomputer on the pointer board to supply power for it through a brush. The rotating carrier needs a 12V voltage source, so it uses a separate power supply method.

System hardware schematic diagram

The hardware principle of the system is shown in the figure below

Design of Optocoupler Sensor Module

The through-beam U-slot optocoupler has the characteristics of fast response, simple drive, easy installation, and easy communication with single-chip microcomputers. As shown in the figure, when the power is turned on, the collector of the phototransistor of the photocoupler outputs low level. When an object blocks the infrared light induced by the phototransistor, the collector and emitter of the phototransistor are in a high resistance state. Therefore, the collector outputs a high level. When the phototransistor senses the infrared light source again, the collector outputs a low level again, thus giving an interrupt signal to the single-chip microcomputer.

Design of display module

The LED display has the advantages of low power consumption, convenient interface control, etc., and the module’s interface signals and operating instructions have a wide range of compatibility, and can directly interface with the single-chip microcomputer, which can easily achieve various operations in various measurement and control It is widely used in meters. When displaying Chinese characters on the LED, the dot matrix data of the Chinese characters should be obtained first, and then written into the display memory for display. Rotating LED display is a new type of display that realizes graphic display by synchronously controlling the position and lighting state of light-emitting diodes. It has a novel structure, low cost, and a viewing angle of 360°.