Currently I am using a Arduino API with the Uno board and it was working fine until few days.
Recently I was working with the interrupt timers and somehow my board went into a mode where I am unable to upload the app.
I have the app which blinks the LED light.
I am trying to upload the very simple loop app but now I am facing below error:
“Avrdude: ser_open(): can't open device "\\.\COM3": Access is denied.”
I have also tried to reboot my PC but still it is not working for me. How to fix above error?