基于单片机的多功能视力保护仪设计

AbstractABSTRACTTechnological advances have increased the variety and use of electronic products,increasedthe burden of schoolwork,and reduced outdoor sports.Various factors have caused problemssuch as excessive eye use and eye fatigue in China's young people,and the myopia rate of youngpeople has increased every year.Decreased vision not only has an impact on the daily life ofadolescents,it may even affect their physical and mental health,and negatively affect the growthand development of adolescents.The growing problem of youth vision is worthy of our attention.Young people's awareness of protecting their eyesight is weak,and their self-control is poor,so ahumanized multifunctional external device is needed to help young people develop good eyehabits and protect their eyesight.The multi-functional vision protection instrument based on single-chip microcomputerdesigned this time selects STC89C52 single-chip microcomputer as the main control module.Through the ultrasonic ranging module,photosensitive sensor module and the internal timer ofthe single-chip microcomputer,functions such as ranging,photometry,and timing can berealized.The temperature sensing module takes into consideration the distance measurementerror caused by temperature affecting the sound wave velocity.The software design part mainlyuses C language for programming,and the initial values of various parameters can bemodified online to meet different needs of users.By using the LCD1602 liquid crystal display todisplay the detected values on the screen in real time,users can intuitively see their distancefrom the vision protector,the current ambient light intensity and temperature,and the remaininglearning time,which can help correct in time when young people learn Its bad learning habitsprevent eye fatigue and protect young people's eyesight.STC89C52 single chip microcomputer is a high-performance microprocessor with fastspeed,integration,high stability,good safety performance,strong scalability,and can implementpowerful data processing functions through scientific algorithms,and can be programmed online.Improve the intelligence of the device.This design selects it as the main control module,connected with other modules,and uses its powerful data processing function to process thesignals from other modules to ensure the normal operation of the system.Ultrasonic ranging usesthe known propagation speed of ultrasonic waves in the air to measure the time it takes for thesound waves to reflect back from the obstacle back to the transmitter after transmitting the soundwaves,and calculates the actual distance from the radio to the obstacles based on the timedifference between transmission and reception.It has the characteristics of non-contact distancesensing,strong directivity,and slow energy consumption.It is widely used in distancemeasurement solutions that use a combination of sensor technology and automatic controltechnology.In this design,the ultrasonic distance measuring module can detect the distancebetween the user's head and the desk in real time.When the distance is too close,the alarmcircuit will send out an audible and visual alarm to promptly correct the user's bad learningsitting posture,protect his eyesight and hunch the user.Prevention also plays a role.The workingprinciple of the photoresistor is that when light shines on the photoresistor,it will excite theelectrons in a stable state inside the resistor,making it a free electron,and the resistance valuebecomes smaller.The photoresistor has a low price,high measurement accuracy and is verysensitive to light.It can well detect the light intensity in the real-time learning environment.In