avrdude: ser_open(): can't open device "\\.\COM3": Access Denied

Using Arduino IDE 1.x
1

I just got my Arduino Uno and I can't upload anything >:( . I don't have anything else that uses ports in my computer. I've tried reinstalling the Arduino program 3 times, Changing the COM, nothing works. >:( :frowning: >:( :frowning: :confused: >:(

2

Check device manager - make sure the device is working properly, no yellow triangle. If yellow triangle, fix driver problems and try again.

If you are using a clone with a CH340G serial interface chip (look at part number on chip next to usb port), you need to download and install the drivers for that. ( CH341SER is the file name, google it).

If you are using v 1.6.8 of the IDE, uninstall it and try 1.6.5r5. 1.6.8 has a bug relating to how it interacts with the serial ports under windows that can cause access denied errors (among other things)

3

If you downloaded v1.6.8 and you are Windows, that release has a problem with making Serial busy.

There is no Sticky on v1.6.8 but several posts on this issue.

I suggest removing 1.6.8 and installing 1.6.5 (r2).

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