The `::init` method in the Adafruit ST7789 library is responsible to
initialize the device. This includes performing a reset, which can be
found in the Adafruit source for `Adafruit_SPITFT`.
Before this change, MeshCore performed its own ST7789 display reset
sequence, which consisted of three steps.
* Pull reset low
* Wait 10ms
* Pull reset high
Importantly, there was no fixed delay after pulling reset high. The
ST7789 driver requires a delay (T<sub>RT</sub>) of 5ms in Sleep In Mode
and 120ms in Sleep Out Mode before it will properly receive commands.
When `Adafruit_SPITFT` resets the device after MeshCore has already
reset it, the mandatory time may not have elapsed, leading to strange
behavior. In the author's case, this issue caused the initial
`fillScreen` to fail, such that the display showed an uninitialized
framebuffer.
This removes the MeshCore delay, leaving the responsibility of reset to
`Adafruit_SPITFT`, where they have the correct delays in place with
extra safety margin. The change was briefly tested by Josiah VanderZee
and Ben Zignego on a custom hardware build using an nRF52840 Dongle and
an Adafruit 4311 TFT display. The user button seemed to behave
strangely, but the display looked correct.
Josiah VanderZee
e56c1b3d58