ESP8266 Community Forum

- Sun Sep 27, 2020 9:34 am #88922 Hi,

This semester we are working with ESP8266 at school. As I was doing the weekly task, I run into this problem:

While the code is uploading to the ESP8266, and the Serial monitor is open I got this error:
'COM4': PermissionError(13, 'Access is denied.', None, 5)

From googling this I found out this problem occurs when two things want to use the same port. My stupid basic solution to this problem would be to switch the ESP8266 or the Serial monitor to two different port. How can I do this?




If the full error log would be helpful, I attached it as jpg

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- Mon Sep 28, 2020 2:54 am #88927 usually the serial monitor is disabled when you start compile&upload (thats why the serialmonotor window gets dim) and only reopening the serial monitor during compilation will interfere. Otherwise it has to be sth other that blocks the upload.

- Mon Sep 28, 2020 12:41 pm #88935 [SOLVED]: Basically what schufti said. If I open the serial monitor during upload it will interfere, so the solution is to open it before or after the upload. Also if I wrote something in setup() sometimes the first few lines didn't show up, but putting delay() after serial.begin() solved the issue