STM32F103ZET6 baseboard compatible with Zhengdian Atomic Battleship V4

1. The double-layer board design
strictly limits the board size to within 10*10cm, reducing board manufacturing costs.
2. Innovative Design:
1) When used with my own design compatible with the Zhengdian Atomic Elite Edition (STM32F103ZET6 core board - JLCPCB EDA open source hardware platform (oshwhub.com)), it can form the Zhengdian Atomic Battleship Edition V4, with more powerful functions.
2) It retains most of the modules of the Zhengdian Atomic Battleship Edition V4, with high fidelity (only lacking the RS232 module, as the package size is too large and the board is too small to fit it). After testing, all functions not involving RS232 can be used normally.
3) The package selected for the Zhengdian Atomic Battleship V4 has been improved, such as changing the potentiometer to a dial type for easier operation.
3. Existing Problems:
1) Due to design flaws, the capacitive touch buttons cannot be used, and the space left in the upper right corner is too small to install mounting holes. (Fixed)
2) High-speed signal lines do not use differential routing, which may affect performance. The wiring is too dense, making it difficult to route differential lines. I'm not very skilled at this. (I've tried to route the traces as evenly as possible.)
3) The pin (PA2) corresponding to button key2 is malfunctioning, causing all buttons to stop working properly. Disabling this pin resolves the issue. However, removing key2 from the baseboard allows it to function normally. The problem is currently unsolved.
 
Thanks to Zhengdian Atom for providing the open-source materials
. This is the second version of the circuit board, fixing the screw hole positions and
addressing the touch button issues. For suggestions, please contact me via email: hhss30804981@163.com.
Thank you everyone.