张小哥

CH549 microcontroller custom USB keyboard

Overview

![4.jpg]

![2.jpg]

## 硬件电路
硬件非常简单，就是一个ch549的最小系统加上按键二极管。
![3.jpg]

## 程序讲解
- **扫描程序**
常规的矩阵键盘扫描方式，digital17共有5行4列，逐行扫描，先把第一行ROW1置为低电平，再扫描所有的列，如果某一列的电平为低，说明这一列有按键按下，依次扫描保存按键状态。
- **消抖程序**
扫描一行的周期是2ms,扫描所有按键一轮周期大概为10ms，扫描8次为80ms，只要这80ms内按键值相同说明这个按键处于按下状态，我采用的做法是用变量把每一个按键的扫描状态保存起来，扫描一轮就左移1位，只要这个按键的扫描状态为0xf0，那么这个按键就是按下状态。
整个程序是在VSCode+SDCC环境下编写的，不涉及任何商业，非常适合开源出来折腾。
![微信截图_20230304142248.png]

**后面的计划：**
1. 整理代码并开源，方便网友自定义按键功能；
2. 折腾上位机，实时更改按键功能；
（ps.等我教资考完考上事业编吧~有时间的话)

Design Files

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