Good luck to all of you guys. I tried to draw the CH340 USB TTL circuit on the Arduino Nano board myself. Yes, I found many different CH340 USB TTL circuits in line with the searches I made on the internet and I drew them all from scratch one by one. At the same time, I produced these circuits that I designed. But I faced the same problem in all of them. When I plugged my circuit into the computer (Windows 10), I got an "unknown usb device" or "usb point reset failed" error. In this case, the following came to my mind:
1- USB port may be broken
2- There may be a driver problem
3- CH340 IC may be broken
4- I may have designed the circuit I designed incorrectly.
1- I tried the usb ports one by one, they all work very well. I also tried the circuit on other computers, it still gives the same error message.
2- I uninstalled and reinstalled the CH341 driver, since the result was still the same, I tried to introduce it manually and even disabled the driver signature checking. The result still gives the same error message.
3- I soldered the CH340G IC, which I soldered to the circuit I designed, instead of the CH340G IC of a working arduino uno, and the computer saw the arduino uno. I was able to program without any problems.
4- In this case, it just shows me that there is a problem in my design, which I do not understand because I drew and produced the circuit designs shared on the internet and shown to work, but I can't think of any other possibilities.
As a result of my research, I also discovered that there are types of ch340 integrated. For example, the ch340c type does not need a crystal. I am sending you the schematics of both circuits that I designed for both the CH340-G type and the CH340-C type. I wonder where am I doing wrong, but the computer does not see the ch340 integrated in these circuits, can't it?
This is my circuit. Here, when I replace the CH340-G integrated with the number 2 with the CH340-G integrated with the number 1 on the arduino uno on the left, the computer recognizes the arduino uno card, but both the CH340-G integrated with the number 2 and the CH340-G, which I numbered with the number 1. When I solder the IC to the circuit board I produced on the left, the computer does not see the CH340-G IC.
Then it isn't a clone anymore. I would expect a clone to behave the same. On an UNO I can manipulate the ATmega16U2 to have additional USB functionality. With a CH340 chip you cannot do that.
You may call it UNO but it's definitely not an Arduino UNO. Sorry for being picky about that.
Thank you all so much guys. Thanks to the advice you gave and the internet, I was able to design a ch340 circuit that can work without any problems and produced this circuit. I was able to program the Arduino pro mini model without any problems. There is one more question I would like to consult with you, without taking up too much of your time. I tried to design and manufacture the Arduino pro mini model myself. But mcu is stubborn in not responding. I would be very pleased if you examine the schematic I have shared with you below and share the errors you see with me. I'm sure it's a small mistake that I overlooked, but my experience is not enough to detect the mistake I made. I hope you can identify where the error is.
Thank you very much for answering and analyzing the circuit. As far as I understand from what you said, adding a capacitor between any vcc and gnd pins seems to solve the problem. I disassembled the 328p I use from a pro mini card that is normally programmed with the ch340 chip. I'm assuming it's the bootloader as it's programmable before dismounting.
Same story for Nanos.