https://blog.csdn.net/m0_69752994/article/details/134107424
https://blog.csdn.net/weixin_37845646/article/details/104686072
用三极管代替IO口的通断效果。
https://blog.csdn.net/m0_69752994/article/details/134107424
https://blog.csdn.net/weixin_37845646/article/details/104686072
用三极管代替IO口的通断效果。