Quasi-nixie tube clock_SiNixie_Clock (under development)

Change log

• 2020.4.15: The PCB of the main control board and touchpad is drawn.
• 2020.4.11: Uploaded the schematic diagram and PCB of the RGB board.
• Temporarily stop updating for a while.
• 2021.2.20: Uploaded RGB test code.
• 2021.8.7: Uploaded hardware details and updated test code

Project Introduction

SiNixie_Clock is a four-digit digital clock that uses RGB LEDs and acrylic panels to simulate Nixie tubes.

This project refers to the design of Gixie Clock and uses a flat-bottomed test tube covered with transparent acrylic to make the lamp. The main control is STC15W408AS. At a frequency of 33MHz, one pin can control the light emission of the RGB LED WS2812B.

Each digit requires 10 WS2812Bs, a total of 40 4-digit digits, and the acrylic thickness is 2mm, so WS2812B uses 3535 package. The diameter of the flat-bottomed test tube is 30mm and the inner diameter is 27mm. In order to reduce the size, the height is planned to be 40mm. We may try 60mm in the future. The numerical order is consistent with that of the Nixie tube, that is, 1234560897.

For control, 4-way touch buttons driven by TTP224 are used.

The upper layer is the touch button board, which is connected to the second layer through pin headers and copper pillars; the lower layer is the main control board, with STC15W408AS on board, and the RGB board is also inserted on it; the bottom of the main control board can be raised with copper pillars .

Since the mechanical part size and fixation issues have been put on hold for a while, the plan has been adjusted and will be updated this year (2021).

Hardware production

Small light panel welding:

casing:

The mechanical structure design of this part is unreasonable. On the one hand, the 2mm acrylic cut is only 1.8mm in actual measurement, which is not tight. On the other hand, I am not good at 3D modeling, so the fixed device is also cut from acrylic, which is easy to glue with 502. Glue the numbers together to affect the display effect. There is a file of the light sheet in the attachment. If you need to make it, you can design the fixture yourself according to the actual acrylic thickness. It is recommended to use 3D printing. The glass shell is a 30*60 flat-bottomed test tube (25mL), which is available on Aobao.

Test shows:

The test code uploaded in the attachment only completes the display function. The DS3231 and button drivers have been written. If you want to do anything, you can improve it yourself. During the debugging process, I found that writing with 51 is more difficult. If I want to improve it in the future, I will probably use STM32F03C6T6 with the Arduino framework. The main frequency of this 51 microcontroller can only be 35M, and it often takes a long time to adjust the number of _nop_() when writing a driver.

Things to note when perfecting the program: The main frequency is 33.1776MHz, and the serial port baud rate for debugging is 9600bps.