On this website, you will find a bunch of awesome projects about electronics and computer. Most of them are designed by myself and ALL of them are open source. I wrote some brief description below:

1. Genie52 Homebrew Computer
   
   This is an 8-bit retro computer which consists of four circuit boards. I designed this tiny platform for some educational purposes, as well as giving tributes to all forerunners of the Homebrew Computer Club. This is a complete system with keyboard/mouse/VGA monitor/music synthesizer. An simple OS can be booted from a USB disk. Some demo applications are installed on the disk as well.
   
   
2. USB Express
   
   I designed a bunch of USB devices when I worked for my employer in China. I will create some pages to share my knowledges about USB data communication.
   
   
3. Audio and Video
   
   I designed a video card and a sound synthesizer for my Genie52 microcomputer. Both of them are implemented with software. I used a MCU to drive a VGA monitor directly via IO port, and another MCU to generate sound through PWM. These are interesting tech worth to be discussed.
   
   
4. Embedded Operating System
   
   I am trying to make an OS Abstract Layer to decouple the application and operating system. If I have to replace the OS of my software, the OSAL will make it easier.
   
   
5. Wireless and embedded network
   
   I am not an IoT (Internet of Things) fans. I create this topic just because integrating some network services into an embedded system with limited resources is a sort of challenging work.
   
   
6. Hardware Description Language and PLDs
   
   I have been dreaming to design my own CPU. I think the RISC-V ISA would be a good start. However, I've never studied VHDL or Verilog or other HDL language.
   
   
7. Simulator and Virtual machine
   
   I wrote a simulator of NES years ago. This simulator runs on my STM32F429 game console as well as on Windows system. I also designed a simulator for my Genie52 computer. If I design my own CPU, I must build a simulator (even a compiler) for it. That's why I open this topic on my wiki.

I decide to choose two kinds of open source license: MIT license and Public Domain.

• MIT license

Copyright (c) <year> <copyright holders>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

• Public domain

It's easy to be written as a piece of comment in my source code, just "P.D."
Sometimes I will write "Copyleft by Zach Lee. All right reversed."
Yes, less is more.

• 09/19/2020 - Yet Another Firmware Based SOFT USB Device.
• 02/11/2020 - USB CD-ROM Emulation on STM32F103C8.
• 08/31/2019 - Implement CMSIS-DAP on STM32F103C8 with EmBitz.
• 08/03/2019 - First page was created.