CH340G cannot download

guominele

CH340G cannot download [Copy link]

I originally wanted to download the software directly through the computer's USB. After the handshake, I could just press switch K1 to power the microcontroller. However, for some reason, the serial port number was lost after pressing the switch. It came back after a while, but I couldn't download. I had to power the microcontroller separately before I could download. There was only one microcontroller on the target circuit board, so there should be no power shortage.

guominele

Circuit Diagram

ddllxxrr

The current is too high, USB protection

qwqwqw2088

The instantaneous current of the switch during downloading causes it to return after a while.

Try adding a slightly larger electrolytic capacitor to increase buffering.

guominele

qwqwqw2088 posted on 2019-7-19 17:04 The instantaneous current of the switch during downloading caused the current to return after a while. Try adding a slightly larger electrolytic capacitor to increase the buffer.

The 47UF/3528 problem has been solved. Thank you very much

chunyang

In fact, if you monitor the power supply voltage, you should be able to find the cause of this problem.