Ceramic LED Filament Digital Tube Clock

This work is my MCU course design, and it has been verified to be feasible. It has the following functions: 1. Display time in multiple modes (display year, date, hours and minutes); 2. Adjust time by buttons; 3. Use APP to adjust time via Bluetooth. However, many problems have not been solved in the process. I hope that a big guy can answer my doubts. I will also modify the project as soon as possible and verify it. Existing problems: 1. If you weld DS1302 by yourself, there is a high probability of losing time when power is off, and a small probability of using the backup battery normally. If the clock module is used, it will operate completely normally; 2. When the digital tube is displayed, some filaments are slightly darker than others. I originally thought that the line width was too narrow, and some shared the same circuit, resulting in a small current allocated to each branch. However, there was no change after increasing the line width, but it may also be caused by uneven filament quality. (The digital tube design is viewed in another project)
And the overall brightness of the digital tube is low, which does not meet my expected brightness. The resistance is even reduced to 1 ohm, but it still doesn't work. I feel that it is caused by the chip current carrying capacity or line width.
At present, the PCB file and the schematic diagram are roughly the same. For convenience, I directly modified the PCB in many places without updating the schematic diagram (a DS1302 module and some pin headers were added, which basically had no impact), so it will be a bit troublesome for the big guys to analyze. I am very sorry. The shell of the clock will be more complicated for the sake of beauty. There are two similar solutions for your reference:
1. Use 3D printed parts to fix the PVC board through the slot and nylon column, which can be disassembled and assembled later; 2. Use double-sided tape to fix it, which is more troublesome to disassemble and assemble again. The program code, model file, bill of materials, and APP installation package will be placed in the attachment. Do not use the exported list. Some components will be changed after practice and are not updated in the project.