STC8H8K64U Desktop Rhythmic Clock

I. Project Introduction
I've been following the training camp for a long time, and each one has made me eager to participate, but I haven't been able to due to various commitments. As a beginner, this is my first official training camp, and I want to experience the entire DIY design process firsthand.
This project combines my knowledge with existing electronic components to create a desktop rhythmic clock based on the STC8H8K64U. It will feature functions such as time and date display, temperature and humidity monitoring, a timer, countdown timer, alarm clock, and rhythmic light strip.
[1] Main control chip STC8H8K64U
[2] 8-digit red common cathode digital tube displays data
[3] Three-legged dial switch controls the interface through single click, double click, long press and other operations
[4] DHT11 sensor collects temperature and humidity data
[5] MAX4466 sound sensor detects ambient sound
[6] WS2812 LED bead realizes desktop rhythmic colored light
[6] Uses classic TP4056 for lithium battery charging, can be powered by USB or lithium battery
[7] 1 serial port can be used for program download and time synchronization and other communication
II. Hardware
The schematic diagram drawn by a novice is not worthy of explaining the hardware principle. It is just some typical charging, acquisition and minimum system circuits. Many design problems were found in the process of making the physical object (which will need to be modified in future versions):
[1] The schematic diagram layout is not beautiful
[2] It is recommended to use a higher version of the web version of EDA for DRC check to avoid incomplete checks by the lower version
[3] The connection of the S and D terminals of P-MOS in the power switching circuit is incorrect (although the power switching can be performed normally, the battery voltage is too low, which will cause the voltage to be unable to be pulled up to 5V when charging).
[4] The current-limiting resistor for the indicator light in the charging management circuit is too small, causing the charging LED to be too bright and affecting the appearance of the actual product (it is recommended to replace R1 with a resistor of about 3.6K).
[5] Since there is a clock function in the design, an external 32.768KHz crystal oscillator should be connected to reduce the time error.
[6] Since it is necessary to synchronize the time with the host computer to set the alarm, a 12P-TYPE-C should be used and a serial port chip should be added to directly complete the charging and time synchronization functions with a single data cable. III. PCB part
of the actual product : 1. Soldering sequence: Solder the surface mount components first, then the through-hole components. 2. The surface mount components can be soldered one section at a time, testing each component for correct soldering. 3. For chips with densely packed pins, use a magnifying glass to check for solder bridging. 4. For through-hole components, solder the toggle switch first, then the digital tube sensor, to prevent densely packed components from being impossible to solder. 5. After successful testing, solder the battery casing: Use a 1.5mm thick dark brown transparent acrylic sheet as a light-blocking sheet . 1. To save costs, cut a suitable area from a large acrylic sheet. 2. Using a utility knife and file for polishing is too much work; it is recommended to use a grinder for direct cutting. 3. The 3D printed casing uses a push-to-open design; errors in the screw hole positions on the upper and lower casings require polishing with a file. IV. Software: The program interface is mainly divided into eight interfaces, which can be switched and data modified by using a dial switch. Upon power-on initialization, the chip ID information is read and sent to the host computer, then the remaining battery power is checked ("2050/4096"), and finally, peripheral ports are initialized, with the progress bar gradually filling in. enum{ date_dis=0,time_dis,temp_dis,clock_dis,power_dis,text_dis,timer_dis,cntdown_dis }mode=1;//Display flags 0->Date display 1->Time display 2->Temperature and humidity display 3->Alarm clock display 4->Battery power display 5->Text lights 6->Timer 7->Countdown 1. Time display interface: "13-23-50" displays hour, minute, and second data. Switch between interfaces using the left and right dials. Press the dial to set the time; the corresponding data will flash as an indicator. Adjust the time data by single or double clicks. If no adjustment is made within two seconds, the adjustment interface will automatically exit. 2. Date display interface: "2024.07.09" displays year, month, and day data. The range of years from 2000 to 2099 can be adjusted, similar to date adjustment. 3. Temperature and humidity display interface: "T.32℃ H.60" displays temperature and humidity respectively. In this interface, long press the dial switch to adjust the brightness of the digital tube in 8 levels. 4. Alarm Clock Display Interface: "00:00 1" displays the alarm time on the left and the alarm switch on the right. A buzzer sounds when the alarm time is reached. A single click on the dial adjusts the alarm, and the corresponding data flashes. If no adjustment is made within two seconds, the adjustment mode is exited. 5. Battery Display Interface: "18352055" displays the noise and battery levels detected by the ADC, respectively. The maximum value for the 12-bit ADC sampling is 4096. 6. Color-Changing Lights: Turns off the digital display and displays colorful lights (customizable light patterns are available later). (6.1 Text Lights: The initial plan was to use a clock-swinging motion to quickly change the brightness of the lights, creating a brief visual display of text or patterns.) 7. Timer Display Interface: "00.00.00.00" represents hours, minutes, seconds, and milliseconds, with a maximum precision of 0.01ms. A single click starts the timer, and a second click stops it. A long press stops the timer and resets the timer to zero. 8. Countdown Display Interface: "-00.00.10--" represent hours, minutes, and seconds respectively. A single click on the button starts and stops the countdown. A long press enters the countdown timer modification interface. Adjust the data by moving the dial left and right. After entering modification mode, clicking the button again switches between data modification modes. If there is no operation for a period of time, it automatically exits modification mode. A buzzer sounds when the countdown reaches zero. 9. Rhythmic LEDs: In addition to changing LED modes, the system continuously collects sound from the MAX4466 microphone and converts it into a rhythmic LED display. Some experiences were summarized during software programming: 1. A chip can be quickly mastered using the STCAI-ISP and official examples in the chip manual. Solutions to similar problems regarding chip design and programming can be found on the STC official forum. 2. Quasi-bidirectional ports can directly read temperature and humidity data from DHT11 components. However, DHT11 modules with 4.7K pull-up resistors cannot be read using traditional quasi-bidirectional ports; the I/O port mode must be continuously changed during data reading or transmission. During transmission -> push-pull output: P2M1 &= 0xfe; P2M0 |= 0x01; During reading -> high-impedance input: P2M0 &= 0xfe; P2M1 |= 0x01; Software improvements needed (to be continued after debugging): 1. Change the ADC power acquisition data to a 0-100 percentage display for greater simplicity . 2. In the rhythmic LED display, set an appropriate R10 resistance value to adjust the gain and filter the data for better display of the rhythmic waveform. 3. The excessively high timer interrupt frequency in the button multi-function scan affects the timing of the WS2812 LED display. 4. After power-on initialization, the display and button functions are unstable.



































5. Although designed for desktop use and not designed for on-the-go charging, a low-power display function can be added.
V. Program Download
1. Select the corresponding chip model and computer port
. 2. Microcontroller IRC operating frequency: 35MHz
3. Set user EEPROM size: 0.5K
4. Do not erase the user EEPROM area when downloading the user program next time
. 5. Automatically open the serial port after programming is completed
. 6. Serial communication baud rate: 115200bps
7. After successful program download, the chip ID information will be automatically read and transmitted to the host computer.
VI. RTC and Alarm Clock Time
Synchronization In the STC-ISP software, select the RTC time synchronization interface and open the serial port:
1. RTC time synchronization baud rate: "115200bps", command header: "@", automatically obtain system time.
2. Alarm clock time synchronization baud rate: "115200bps", command header: "#", format: "hour:minute start/stop" (1 start 0 stop)
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