We are excited to announce the expansion of our partnership with SparkFun Electronics to include the manufacturing of all Teensy products. Teensy 4.0, Teensy 4.1 and related accessories will now be manufactured by SparkFun in Colorado, USA...
NXP, obviously, though inconsisteny like "F(op)" versus "F(SCK)" kinda makes it look like copypasta.
An NXP employee or contractor risks a reprimand or poor performance review, if there's even the slightest implication they advised you to do...
Problems can also happen entirely on your PC. Usually you would see an error message. The most common problem is some other program (not the Arduino IDE) tries to access Teensy. Especially with Windows, when another program has opened access...
The most common problem is disabling interrupts for too long, either by intentionally using noInterrupts() or cli() or similar, or by your own interrupt function which takes too long and thereby blocks other interrupts until it completes.
When...