Compact 40-key inline mechanical keyboard [Atmega32U4]

This project is changed from https://oshwhub.com/iqirtryi/pbk40-rgb-keyboard-c. The original project used a pro micro module, so the keyboard was thicker. At the request of PMM, a member of this project, it was changed to an onboard master control. Atmega32U4 was directly removed from the original module, and a high-low shaft and a sinking Type C port were used to make the keyboard thinner.
 
Borderless version: The positioning board, circuit board, and bottom plate are designed with a splicing board to reduce the production cost.
The two circuit boards are spliced ​​together with wires. The 32U4 master control and C port only need to be soldered on the left side of the diagram.
 
The sinking C port is used, and the height of all electronic components is controlled to the height of an aluminum substrate.
 
The bottom plate made of aluminum substrate has a hole for burning corresponding to the position of the RESET micro switch.
 
The borderless version was made by PMM, and the lovely fresh green was given to him and her. Bordered
 
version: The original keyboard was modified, and the copper fixing, copper bottom, and frame were used as the original keyboard, and the circuit board was designed with a splicing board.
Feeling the invincible feel brought by the thinning of the keyboard, I couldn't help but transform my previous main keyboard. Yes, it's her:
the simplest programmable inline keyboard with RGB, suitable for novice production.
 
First feel the difference in height before and after the transformation. Both use low-profile shafts, which are reduced by nearly 5mm after the transformation.
 
I have always been worried about the terrible craftsmanship when I re-entered the arena. This time, the craftsmanship has been greatly improved after using the heating table.
 
The heavy feeling of the copper base and copper bottom, coupled with the high-profile low-profile shaft and the sinking plate C-port design, feels first-class, and it is easy and not tiring to type for a long time.
 
 
Bronze + classic black and red, full of retro industrial style.
 
Layout design:
Because I have also played a 30-key small keyboard recently, the key position design has also been changed. The number keys and direction keys are as consistent as possible with the 30 keys. For reference only, please improve according to your own habits and needs.
 
0 layer: letters + function keys. Long press Fn1 to enter the number and punctuation layer, Fn2 to enter the direction key and punctuation layer, Fn3 is the F function area, virtual mouse, and Fn4 is the software shortcut key and media key. Press Fn1 plus Fn2 to switch Chinese, press Fn1 plus space to switch uppercase and lowercase. When entering Chinese, press the space with your right thumb to select the first word, press Shift with your left thumb to select the second word, and press Shift with your left thumb to enter capital letters. All operations do not require leaving the main area.
 
Layer 1: The left side is the numeric keypad, and the right side is part of the punctuation marks. All punctuation marks should be arranged according to personal habits and easy to remember, such as? It is the F position of Fa asking questions, # is at the J position of the pound sign, ~ curve q, @at, [square bracket Z, {curly bracket K, right stroke N, $Us knife, "double quote S, ... +-×/= take into account the use of the numeric keyboard. I like shortcut keys, so I set up reserved shortcut key combinations in the empty space of each layer, as shown in the lower right corner of the figure, in which: # represents win, ^ represents ctrl, ! represents alt, + represents shift.
 
2nd layer: the left side is the remaining punctuation marks, and the right side is the arrow keys. Now put your hands on the keyboard, it is natural for the left thumb to press Fn1, and you will feel that the numeric keypad is below, and the right finger presses Fn2, and you will feel that the arrow keypad is below, which is very natural and comfortable. Once you
 
are familiar with the above 3 layers, you can use this keyboard normally. If you want to further improve efficiency, it is recommended to use other layers well, and you can use QMK to adjust them according to your needs.
 
Layer 3: F area, shortcut key area, virtual mouse area. Press Fn3 below with your left or right thumb, then press the shortcut key in the middle or the virtual mouse on the right. I found that one-handed operation is also very convenient. I basically don’t use the F area, so I set it on the far left.
 
Layer 4: Media playback keys and shortcut keys for launching commonly used software. Fn4+letter is equivalent to Ctrl+Alt+Shift+letter, which can be set as software shortcut keys in Windows, such as Fn5+C to run Chrome, Fn5+W to run WeChat, Fn5+M to run music software, Fn5+V to run video software... The shutdown and restart shortcut keys ^!+. and ^!+, are set in the lower right corner. Since using the software shortcut keys, there are no software shortcut icons on the entire computer desktop, and my obsessive-compulsive disorder has been cured.
 
In the process of using the small keyboard, I continue to improve the layout settings according to my own needs. For the latest version, please see: http://www.keyboard-layout-editor.com/#/gists/8d5ba77e61b6809944f90e0ea130a144 for reference. For
 
the specific production process, please refer to: https://oshwhub.com/iqirtryi/pkb16x4-atmega32a
Main component purchase link: https://docs.qq.com/doc/DYWFPbGdhZ0puV2V6
 
The advantages of ATmega32U4 are: it has its own USB interface, and does not require a burner to burn the Bootloader. It is fully supported by QMK, and can generate firmware online. Firmware generation and burning are simple and easy. But the price is high, and the MU package is difficult to weld. Novices can choose the Pro Micro module solution with lower production difficulty. The
same arrangement can also use a lower price and lower welding difficulty solution, which requires a burner to burn the Bootloader: https://oshwhub.com/iqirtryi/kb40-atmega32a
 
There are many small arrangement keyboards, please see my homepage for details: https://oshwhub.com/iqirtryi
 
 
Reference materials, thank you for your contribution!
1. Must-read guide:
Zero-based assembly: https://www.zfrontier.com/app/flow/2wqGYOQPMpOQ
Quickly learn to make your own: https://www.bilibili.com/read/cv5275203/
QMK flashing tutorial: https://post.smzdm.com/p/aekz8pdm/  
2. Advanced reading: QMK environment construction: https://www.bilibili.com/read/cv10071032/
RGB light settings: https://www.zfrontier.com/app/flow/2dq9AoE37KpE 3. Tool website: QMK official website: https://docs.qmk.fm/#/zh-cn/ Layout editor: http://www.keyboard-layout-editor.com/ Online firmware generation: https://kbfirmware.com/ Positioning board shell: http://builder.swillkb.com/  
 
Thank you for your attention. If you find it interesting, please like + comment + collect it!