Rework display spi driver:
use DMA for read, write
add blitBitmap functions
Use DMA for color fill
More correct SPI bus control
Move color definitions to nanovna.h
Some code optimization for speed and size (save about 3k bytes)
Change grid Y resolution to 10
Fix convert from float to int (fix some rounding errors on plot)
Disable unused HAL serial
Change battery icon
DiSlord
TT
cho45