☆ Design Hardware Composition: STM32 microcontroller minimum system + RTC clock module + HC-SR04 ultrasonic sensor + photoresistor sensor + LCD1602 display + AT24C02 storage chip + lighting circuit + button settings + buzzer + red LED light
1. This design uses the STM32F103C8T6 microcontroller as the main control chip;
2. Real-time display: The LCD1602 displays the current time, date, distance between the user and the vision protection device, light intensity, and reading countdown in real-time;
3. Clock timing: The RTC function module of the STM32 microcontroller is used to keep track of the date and time, powered by an external button battery to ensure the clock continues to run even when the main power is disconnected;
4. Posture reminder: When the distance between the user and the vision protection device is less than the set minimum distance, the buzzer will sound and the red LED will flash to remind the user to maintain distance. When the distance exceeds the alarm value, the sound and light reminder will automatically turn off;
5. Light control: The system detects the ambient light intensity using a photoresistor and automatically adjusts the PWM to control the brightness of the light based on the set light intensity threshold;
6. Reading reminder: A reading countdown is initiated, and when the countdown reaches zero, the system will sound the buzzer to remind the user to take a break; 7. Alarm reminder: The alarm time and working mode can be set using buttons, with multiple modes available for different scenarios. When the alarm time is reached, the system will keep the red LED light on and sound the buzzer. The user can manually turn off the sound and light reminder, and it will automatically turn off after one minute;
8. Setting functions: The buttons allow for calibration of date and time, setting reading time, setting minimum distance alarm value, light intensity threshold, alarm parameters, etc.;
9. Power failure storage: The parameters set will be saved using the AT24C02 storage chip, achieving power failure protection storage functionality;