mjs513
Senior Member+
@mjs513 - did a build from your test - my machine shows device Teensy MTP Disk - but 'Unavailable' ...
I started with mtp-test.ino - but replaced with your posted code dropping the pin13 toggle?
It built fine : on a T_4.0 with Audio card - so something isn't set right perhaps ...
Not sure about the 'locked' - I was here late too - didn't see that and didn't try to do it ... fixed now.
Chip select is defaulted to pin 6 and defaults to SPI for now.