Thanks for the info. In fact your compilation took less than 2 seconds and worked fine.

The errors list in visual studio is no connected to the actual compile. For the compile we use the external tools that come with your platform, for intellisense we point vs to as many paths as possible, set a few defnes and then let it do what it wants to do. It should be much better than you see but maybe never 100% perfect.

Intellisense

We will look into the intellisense for the platform you are using and that will probably result in some newer toolchain paths spec. which we will release in a new build during the coming week or two. In the meantime if you switch the drop down lists above the Error List to "Build Only" or some other settings that give less confusing errors it might help.

Compilation

As I have said your output shows the build took just under 2 seconds. I would expect it to be much slower on first compile because it builds and then caches the core. The arduino IDE would also do the same cachning which means subsequent builds should also be sub 2 seconds.

With that in mind I am confused about what you have said about Visual Micro being very slow during build. Based on what I have said and the output you see during build, can you confirm where the slowness happens exactly?

Please also make sure the toolbar is set to Release and not Debug when making your tests.

Thanks

Great. If you click "Build>Clean Solution" that will zap the cache and your first build will be slower again because the core is being compiled.

In the Arduino IDE, depending on the file>preferences, it might make a complete rebuild when you switch board or change any of the board menu settings. Because you had been using the arduino ide for a while without changing the options I mentioned it might have been working with a cached core.

In both IDE's you should generally see a fast build until something major changes. Then slow build followed by fast again.