Error uploading a sketch when Serial Monitor is open in another sketch

Azerla · November 6, 2021, 5:33am

With the Serial Monitor open in a running sketch, I can not upload another sketch without first closing the running sketch. I get the following errors:
avrdude: ser_open(): can't open device "\.\COM4": Access is denied.
Upload error: Error: 13 INTERNAL: Failed uploading: uploading error: exit status 1

In the previous versions of the IDE, I could have one sketch running with Serial Monitor open, and upload another sketch when I had the data I needed from the first sketch. However, in 2.0 beta, it's not possible if Serial Monitor is open in a running sketch., it results in a failed upload with the above error messages.

The only way I can upload the second sketch is to completely close the first sketch.

This is most annoying, and I've had to go back to the previous version of the IDE until this issue with 2.0 beta is corrected.

gilshultz · November 7, 2021, 3:21am

Are you running Windows? I generally have several sketches is open concurrently each connected to a serial monitor without any problems. I select the sketch and upload code without any problems with the appropriate IDE. I have been doing this for years. Currently I am using Arduino 1.8.13 IDE operating under Linux Mint! To keep from getting confused I generally place each sketch, and monitor window in a different workspace.

ptillisch · November 7, 2021, 3:42am

Hi @Azerla. The Arduino IDE developers are tracking this problematic user experience here:

github.com/arduino/arduino-ide

Upload fails if port is open in Serial Monitor of another window

opened 02:16PM - 31 Oct 21 UTC

closed 05:55AM - 08 Jun 22 UTC

per1234

topic: documentation conclusion: resolved topic: code type: imperfection topic: serial monitor criticality: medium

## Describe the bug It is not uncommon for a user to have multiple windows op…en with the same port selected in each. If the Serial Monitor is open in one of those windows, uploads from the other window will fail. ## To Reproduce 1. Connect any Arduino board to your computer. 1. Select the board and port in the Arduino IDE menus. 1. Open Serial Monitor (e.g., **Tools > Serial Monitor**). 1. Select **File > New** from the Arduino IDE menus. 1. Select **Sketch > Upload** from the Arduino IDE menus. 🙁 Note that the upload has failed with an error something like "`avrdude: ser_open(): can't open device "\\.\COM7": Access is denied.`" ## Expected behavior Handle sharing port usage between windows automagically. **OR** More effectively communicate the cause of the upload failure and the required action to the user. **OR** Clearly document the cause of the upload failure and the required action (https://github.com/arduino/arduino-ide/issues/271). I would recommend taking the approach of *"so you have x problem, here is the solution ..."* rather than *"here is how to upload/use Serial Monitor properly ..."*. The reason is that the user is much more likely to go searching for a specific solution once they have the problem than to proactively study the documentation in advance of doing an upload. With this approach, the appropriate location for the documentation would be [the Help Center](https://support.arduino.cc/hc/en-us/sections/360003198300). The [classic Arduino IDE points the user there](https://github.com/arduino/Arduino/blob/1.8.16/arduino-core/src/cc/arduino/packages/Uploader.java#L179) in the event of a failed upload. The article should be titled with the unique components of the various common error messages that occur when attempting to upload to an open port. It should also take into account that there are multiple possible causes of this error. ## Desktop - OS: Windows 10 - Version: 2.0.0-beta.12-nightly.20211028 Date: 2021-10-28T03:03:25.353Z CLI Version: 0.19.1 alpha [718bbbf2] ## Additional context Originally reported at https://github.com/arduino/arduino-ide/issues/271#issue-840803269 ### Comparison to classic Arduino IDE This is not usually a problem in the classic Arduino IDE because all windows share the same Serial Monitor and are able to juggle the control of the port between the upload process and Serial Monitor automagically. The exception is when the user has opened multiple instances of the Arduino IDE, in which case it behaves the same as Arduino IDE 2.x in that each instance has its own Serial Monitor and can not control the Serial Monitor of the other instance. However, this multiple instance usage is not very common, and more often employed by advanced users who are easily able to identify the cause of the upload failure that results from these conditions.

If you have a GitHub account, you can subscribe to that issue in order to get notifications of any developments.

Arduino IDE 2.x works differently than the classic Arduino IDE in this respect. The classic Arduino IDE actually has the same behavior when you use multiple instances of the IDE.

When you only have a single instance of the classic Arduino IDE running, every window of that instance shares the same board and port setting, meaning you end up switching those settings a lot if you are working with multiple boards at the same time. That is not a problem with Arduino IDE 2.x because every window is a separate instance.

Azerla · November 7, 2021, 3:02pm

for gilshultz

Yes I'm running Windows 10, but I posted the issue here as it appeared to be the forum for matters pertaining to IDE 2.0 beta. I used IDE 1.8.13 with no problem, but when using 2.0 beta I get the originally posted issue.

gilshultz · November 9, 2021, 2:09am

Sorry I missed the bata. I have an old version by several years that is Arduino 2:1.0.5+dfsg2-4 and I thought that was what we were talking about.

system · May 8, 2022, 2:10am

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