Problem uploading to board. See for suggestions

Abhimanyu's picture


Joined: Sep 14, 2018

Replies: 0
Problem uploading to board. See for suggestions
August 1, 2019 - 1:13pm

Hi. i am using arduino UNO for my project. I am doing a project on LCD interfacing with Arduino UNO. My operating system is Windows10. while upoading the arduino sketch to my arduino UNO board i get the following error: 

avrdude: ser_open(): can't open device "\\.\COM14": Access is denied.
Problem uploading to board.  See for suggestions.

I went to the arduino site but i got no solution the above error. I was able to program my arduino uno with same sketch while ago but i have started receiving the above error. can you please tell me the possible reason for this error. 


Abhiemanyu Pandit's picture


Joined: Jan 21, 2019

Replies: 42
Problem uploading to board. See
August 1, 2019 - 6:26pm

okay so this happens with the windows10 OS only. The problem here is with your serial monitor. In windows, if you  try to upload the program while the serial monitor open, you cannot upload any sketch from that COM port.

So check if your serialmonitor with same port is open in some other arduino window. If it is open then close the serial monitor and then try uploading the sketch again. 

also note that this happens only when you try to do two things at the same port like you want to upload sketch and also you want to open serial monitor. 

it is possible to run multiple COM port serial monitor in multiple windows but with different PORT selection. 

ultimately for your problem try to check if the serial monitor with same port is open in some other window.