ESP universal downloader

1. Introduction
Most of the ESP32 core boards currently on the market use CP2102 from Siliconlabs as the serial port chip. However, after my research, this chip cannot achieve fully automatic program downloading, so I have to use it every time I download a program. It's super troublesome to hold down the IO0 button to ground the IO0 pin.
After my discovery, on the contrary, relatively old-fashioned serial port chips such as Nanjing Qinheng's CH340x series can realize fully automatic program downloading, and the price is even cheaper.
 
2. Introduction
Nanjing Qinheng’s CH340 series has multiple models, each model has different functions. Combining factors such as functions, number of required peripheral devices, price, etc., CH340C is a good choice. Compared with CH340G, it comes with its own crystal oscillator. Compared with CH340K and CH340X, it is cheaper and does not require the storage function of CH340B.
It’s already 2023, how can there be no Type-C interface? A 16-pin Type-C interface is used here, which is a bit difficult to solder by hand.
 
3. Physical pictures