I have an lpcxpresso 54628 board and a 552s28 board, and I figured I'd get up to speed on the tools by looking at examples.
To that end, I imported a handful of examples from the current 2.12.0 SDK.
I notice that none of the examples bother with the MCUXpresso config tools; that is, there are no .mex files in the imported projects.
For example, I imported the lpcxpresso54628_dev_audio_speaker_bm example. There's no .mex file. I choose the MCUXpresso Config Tools option from the "Miscellaneous" section of the Quickstart panel, and choose "Open Peripherals."
The Config Tools Overview window opens. At the top is a small red X and the line, "Peripheral tool is disabled. Either enable it or select different tool." Over to the side is a USB symbol in a circle, under "Peripherals" and its switch is off. I turn it on. I see a lot of stuff about having to generate and update files, so I do it.
I find the Middleware for USB, and it's got a red X and I think I just destroyed the example. Is this how it's supposed to work?
I'd like to implement the simple USB MIDI class as an example to prove that I understand the device. There's no clear way to even start creating this, as there are canned options but nothing that lets me specify the MIDI streaming interface or set up the descriptors.
At some point I see the .mex file created, but I'm not sure how relevant it is.