fluorescent tube clock

0.What is VFD?
VFD (VACUUMF LUORESCENTD ISPLAY) is a display device developed from vacuum electron tubes. It consists of a cathode (direct heating type, collectively referred to as a filament) that emits electrons, a shed that accelerates and controls the electron flow, and an anode with electrodes and phosphor printed on the glass substrate. And composed of grid and glass cover. Its display method is a bit like an old-fashioned tube TV. The electrons emitted from the cathode are accelerated and bombarded onto the phosphor, causing the phosphor to emit light and thereby display the pattern. People often confuse fluorescent tubes with Nixie tubes, but in fact the two are completely different display technologies: the inside of the fluorescent tube is a vacuum, and electrons bombard the phosphor to make the phosphor emit light. The inside of the Nixie tube is filled with neon and argon gas, and the glow is emitted by the gas being ionized by high voltage to display the display. If you are interested, you can browse Teacher Yan Zeyuan’s NIXIE/VFD technology, which is very clear and detailed.
1. About the VFD fluorescent tube IV-18 used in this project.
The fluorescent digital tube IV-18 used in this project was produced during the Cold War period of the former Soviet Union. The main advantage is that the tube size is relatively large. The overall height of the digital tube is 115.0mm and the diameter is 11.5mm. The display area of ​​the internal pen segment is 10.5mm high and 7.4mm wide. The display area is much larger than that of traditional fluorescent display tubes, and the display effect is naturally more eye-catching. And I especially like the design of the transparent glass substrate, which has a cool feel. Hard style.        2. Function introduction:
This product has basic travel time and network time adjustment functions (needs to be connected to wifi). It also adds a BME280 sensor to monitor the current temperature, humidity and air pressure in real time.
3. Supplement:
Due to the poor code level of the poster, there are still many bugs in the software part, which are still being optimized for the time being
(2023.05.17) Update:
The second version of the PCB has been finalized, and the hardware part is still being optimized. The main optimizations are:
       1. Two PCBs are compressed into one, reducing the number of board printing times.
       2. Optimizing the positions of buttons and type-c interfaces
       . 3. Simplifying the four-layer board into a two-layer board. Variable colors can also be printed for free.