STM32F411CEU6 Minimum System Board with Built-in DAPLINK

PDF_STM32F411CEU6 Minimal System Board with DAPLINK.zip

Altium_STM32F411CEU6 Minimum System Board with DAPLINK (.zip)

PADS_STM32F411CEU6 comes with a minimum system board for DAPLINK.zip

BOM_STM32F411CEU6 Minimum System Board with Built-in DAPLINK.xlsx

92448

CV numeric keypad

The replica keypad has been modified with changes to the Type-C package, some wiring, and shorting points. The panel now has more backlighting, and the specifications of the copper pillar screws have been adjusted.

Modified from: 3-Key CV Keyboard_Three-Key Engineer Keyboard_CH552G - LCSC Open Source Hardware Platform (oshwhub.com)
. Thanks to the original author.
Modified the Type-C package, modified the programming button, modified the wiring, added LEDs, added keyboard panel backlighting, and adjusted the size of the screws in the same group.
Ignore V2.0, only look at V3.0 and the positioning board. The base plate can be replaced with a V3.0 board for aesthetics.
When soldering the Type-C, be sure to fix it on both sides. If you only solder the four positioning pillars from the back, it is easy to pull them out completely. Always fix it on both sides. The temperature should not be too high, otherwise it will burn the plastic and make soldering more difficult. Other aspects will improve with practice. The original author has already provided a good description, so I won't go into detail here.
The keyboard backlighting uses a copper-pile barrier layer and a solder mask layer, which has an ideal effect and can be clearly seen in the PCB file. The boxes and crosses in the document layer are used to find the center of the circle.
From top to bottom, there are screws, double-through copper pillars, and single-through copper pillar screws. The top plate (positioning plate) is 1 mm thick, and the other plates are 1.6 mm thick. This design securely holds the mechanical key switch in place, preventing it from moving forward, backward, left, or right, while still allowing for easy insertion and removal. This fixation is already very stable. If you want the mechanical key to be firmly secured to the panel, the original design allows for a 1.6 mm thickness, meaning you need to use a 1.6 mm top plate. Additionally, the length of the copper pillars needs to be adjusted to ensure that the distance from the top surface of the central layer to the top surface of the top plate is 5 mm. WCHISPTool_Setup.exe - Nanjing Qinheng Microelectronics Co., Ltd.
BOM
CH552G 
TYPE C Female Socket JLCPCB C2765186
3 x 100nF 0603 Capacitors OR 2 x 100nF 0603 Capacitors and 1 x 10uf 0603 Capacitor
1 x 10k or higher Resistor (optional, as shorting is not required with my method)
3 x Kailh Hot-swappable Switch Sockets
3 x Switches (any 5-pin or 3-pin compatible
) 3 x Keycaps (any keycaps)
2 x 5.1k 0603 Resistors
2 x 1k 0603 Resistors
2 x 0603 LED
Screws are M2, see reference image

PDF_CV Keyboard.zip

Altium_CV keypad.zip

PADS_CV numeric keypad.zip

BOM_CV keyboard.xlsx

92449

STC32G core board

Using STC32G12K128-LQFP64 to build the core board

The STC32G series microcontrollers are 32-bit 8051 microcontrollers that do not require external oscillators or external resets. They are designed for superior anti-interference, ultra-low cost, high speed, and low power consumption. At the same operating frequency, the STC32G series is approximately 70 times faster than the traditional 8051.
 
They feature an onboard CH340N chip, eliminating the need for an additional programmer.
An onboard AT24C02 chip ensures data retention even after power loss.
Buttons control the MOSFETs to manage power supply, enabling a hard reset and facilitating program downloading.