When I use the TFT_eSPI library, The orange led on teensy 4.0 board is permanent on, but not if I use the teensy ST7789 library, how can I turn it off?
If Pin 13 is used as SCK - AFAIK it will light during transfers and cannot be turned off if active. Either using an alternate pin or transfers are too fast/few between to see in bright light - if it is working.
No notes or images of wiring or code - so just noting normal expectations.
Have to assume this is the github.com/Bodmer/TFT_eSPI - no idea what that code does with ST7789 controller, versus the one made for Teensy.
Does the device or the TFT_eSPI have Touch interface enabled? If the library is reading for TOUCH the reads may be continuous - they were when monitoring for the Teensy ILI9341 touch - until the interrupt pin testing was added.