I installed the new IDE Environment 1.6.6 and I got this error when compiling a program. I am using an Arduino Uno
avrdude: ser_open(): can't open device "\\.\COM4": access denied
I need your help.
I installed the new IDE Environment 1.6.6 and I got this error when compiling a program. I am using an Arduino Uno
avrdude: ser_open(): can't open device "\\.\COM4": access denied
I need your help.
I had this very same issue. I solved the problem by shutting down my outside cameras. Once cameras were off (the software) the program worked. It was the camera software that was using the port.
So if you have a lot of other software or equipment running in the background this may be your problem. Just try shutting down things one at a time. That's what I did until I found that the camera software was my problem.