I have an clone arduino mega 2560 with the CH340, with that board i tried turn into an Arcade joystick, but i cant Beacuse the board has an CH340 so that board cant do DFU mode, so i think to use an USBasp to burn directally the .hex file of the Megajoy or burn the 16u2, BUT the board dosent has the iscp Pins to do that, anyone knows what i can do to burn the hex file or i have to buy an arduino with the 16u2?
Your board can't be used as joystick, so you either have to buy an arduino with 16u2, or, better, choose the board with mcu with native USB, such as Pro Micro or Digispark
You might be better off buying a board that supports native USB like an Arduino or Micro, a SparkFun Pro Micro or one of the more modern boards (most of them with exception of Nano Every will probably do).