2.0! ATMEGA32U4 development board verification board minimum system board

1. This project is used to verify the solution verification board design of the 8-bit microcontroller ATMEGA32U4-AU from Lichuang Mall.
2. This design is a minimal system based on ATMEGA32U4 microcontroller (leonardo minimal system)
3. The ATMEGA32U4 microcontroller is a commonly used keyboard and mouse analog chip. It can be used to develop custom keyboard and mouse, or it can be developed like the Arduino Micro series.
4. This design mainly includes power circuit, crystal oscillator circuit, reset circuit, programming interface, micro data transmission circuit, and other peripheral auxiliary circuits. And all available interfaces are introduced to facilitate development and design.
5. This design is compatible with the Arduino Micro series development boards and can realize most functions. It can develop a series of keyboards and mice, such as the commonly used 104-key keyboard, customized high-quality GH60 keyboard, and can also develop less popular configurations, such as 96-key, 87-key, 75-key, 64-key keyboard, etc. You can also customize the keyboard arrangement for development, and it is easy to program.
6. The smaller size allows you to be bolder in development! Let's create a miracle!

This is the 2.0 upgraded version, which improves all the problems that occurred in the previous version (including line signal optimization, welding problems, debugging problems, etc.), making this project more mature. Specific improvements:

1. Improve signal interference between lines and make it more stable.
2. Re-layout, reduced size, easier to develop (within 3*3cm)
3. The micro interface has been replaced, which is easier to hand solder than the previous project.
4. Replace the two-leg passive crystal oscillator, and you no longer have to worry about damaging the crystal oscillator with hand soldering.
5. Solved the problem of the reset button in the previous version becoming the self-destruct button. Original elimination project link: https://oshwhub.com/XIN_sk/ATMEGA32U4-kai-fa-ban-yan-zheng-

Note, you need to burn the BootLoader for the empty film. As for where to find bl, ask the Arduino IDE. The file is too big to be uploaded... 555 Let me tell you secretly, Lichuang's 32U4 comes with BL... It smells so good

An unsoldered empty board (there are two edges that are not finished, I don’t know how to do it...) After welding, I first made a small keyboard, and it is feasible in actual testing.