一些不错的网址

http://www.mcublog.cn/esp32/2019_12/esp32smokuaidezuixiaoxitongyuanlitu/
ESP32S模块的最小系统原理图。其中提到了”一键下载电路”
（MCU起航_关注物联网与硬件设计的单片机爱好者）

https://github.com/HX-IoT/ESP32-Developer-Guide
https://github.com/xiaolongba/HX_DK_FOR_NORDIC_52840_BLE
https://blog.csdn.net/qq_24550925/article/details/85333868
https://blog.csdn.net/qq_24550925/article/details/85933563

https://www.qutaojiao.com/3085.html