I bought a new Arduino Uno clone SMD that uses a CH340 chip. When I plug in the USB cable my Windows “operating system” could not detect the device, even though I installed ch340ser.exe
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Then I connected my Arduino Uno clone using a TTL USB to serial adaptor... Tx to Rx, Rx to Tx, 5 volt to VIN, and GND to GND.
I somehow managed to upload the Blink sketch to my Arduino Uno using that connection. But the success rate is low. I need to do it several times and press the reset button several times before it succeeds at uploading.
Is there any other pin that need to be connected to VCC or GND during upload process?