CH340E USB to TTL Wiring as follows: (only need to connect 3 wires) TXD terminal of USB downloader -> connect single chip microcomputer P3.0 (RX) RXD end of USB downloader -> connect single chip microcomputer P3.1 (TX) GND end of USB downloader -> connect single chip GND Wiring is as follows: (only need to connect 3 wires) TXD terminal of USB downloader -> connect single chip microcomputer PA10 (RX1) RXD end of USB downloader -> connect single chip microcomputer PA9 (TX1) GND end of USB downloader -> connect single chip GND The CH340E USB to TTL or small system is powered by a separate power source. Or use the USB downloader to provide 5V power supply board. In the download, you need to connect boot0 to VCC. After the download is complete, connect it back to GND and press the reset button to complete the operation. Support win7 32-bit, 64-bit operating system, support win xp operating system
