If I want to debug my Feather M0 then the device regularly returns to ATSAMD21E18A instead of ATSAM21A18A. If I adjust this in 'proportions (device)' or via 'device programming' this is always adjusted again. I have the impression that when I toggle between 'Debug: Hardware' and 'Debug: serial' and 'build and upload', it always goes back to ATSAMD21E18A.

In which file (/ option) is this processor defined?

ok, E-mail is send.

output en screenshot  in E-mail(visualmicro@outlook.com) send

Thanks for sending the output. The core for that board does not clearly state an mcu id so we have to guess. 

If we look at the core it has a disguised _D define in the build command equal to SAMD21G18A

I think the only solution is for us to add a custom property where you can set an mcu override when using atmel studio. There is a release due over the next few weeks where we will try to include that.

There is an interim release in the forum with a new menu item that you should switch off, after doing so your device selection will be retained. "vMicro>General> Automatic Attempt to Set Atmel Studio Device" = OFF

https://www.visualmicro.com/forums/YaBB.pl?num=1580914071/0#0

Let's be sure we are talking about the same setting? See picture. Uncheck the menu then change the mcu using the std. atmel dialog(s). After doing so, right click "project>property pages" should show your newly selected mcu. Visual Micro should not then change the mcu selection even if you switch to a different Arduino board in the board list.

You seeing different?

look at doc. voor de scenario's.

Your doc does not show how you have changed the mcu name using the atmel studio selection controls. Please show which atmel studio element you click and which window you use to select the correct mcu

Thanks

Strange, there are only two lines of code in visual micro that set the atmel project device name and both are in the place, ignored when the setting you have off is off. 

Please follow the guide in yellow above so that I can see your build properties. Please also zip and email your .ccproj file.

Also confirm the exact atmel studio version from help>about. I am starting to wonder if it is an atmel bug in an older version of atmel. 

Thanks

Thanks

Your atmel studio project file shows your change of device has been applied and saved to disk so this sounds like some issue with atmel studio. Or maybe you need to click save on the project before sending the cpp? Did you click save after the mcu had changed back to the wrong value? Did you re-open the project to see if atmel corrects the UI? 

This is what atmel writes to the cppproj file when you make a change. If you can open the project and see that it is wrong, then click save. Then look for the avrdevice to see what that is set too, it would be useful.

<avrdevice>ATSAMD21G18A</avrdevice>