Recently in learning how to draw the board, and then want to draw a arduino mega circuit headphones
Then about the program download circuit is used a usb serial interface chip, most compatible with plate with chips are ch340g circuit diagram about the following

Then I went to checked the ch340 manual, there was another chip ch340n

I just want to use this ch340n to replace ch340g
But the original schematic diagram used in DTR, the pin but no DTR ch340n, only the RTS pin

Checked the information about Modem communication
DTR data terminal ready RTS request
Ch340n can be used as a substitute for it in the end, how should do, the younger brother thank you bosses here

CodePudding user response:

Turn on the market of USB series, use the UD +/- only commonly, Rx/Tx, Vcc/GND pin function used to shake hands, and flow control, has been basically useless