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

Development Tools IDE 1.x
9

solution!!!!

  1. device manager
  2. select ports
  3. select port of arduino board examle : com1 ... com3 whatever it is
  4. right click on com.
  5. select properties
  6. tab- port settings
  7. click advanced
  8. com port number- select new port number that is not in use.
  9. confirm..
    save and continue

the problem is a conflict between hardware devices, ie. the port is now used by another hardware device, mouse, ect..

4 Likes