GxEPD2 sends the panel RAM a byte at a time; on the nRF52's SPIM the
per-call overhead dominates, and an 800x480 partial refresh writes the
whole 48 KB several times. GxEPD2_426_GDEQ0426T82_Fast overrides the three
image writes to send each row in one transfer() call, falling back to the
stock path for the cases it doesn't cover (first write, mirror_y, PROGMEM).
Byte-for-byte the same data as the stock driver.
Opt-in per env: -D EINK_FAST_WRITES=1, and EINK_SPI_HZ (default 4 MHz,
8 MHz here, SPIM2's ceiling).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KxAZVAbhhYr18Dd4guTQM1
New solo env WioTrackerL1_GDEQ0426T82_companion_solo_dual: the Wio Tracker
L1 (Lite) with a Good Display GDEQ0426T82 (SSD1677) on the board's 24-pin
e-ink FPC. Build config only. Extends WioTrackerL1Eink with its own full
build_flags list so the stock panel's model and rotation never reach the
compiler.
RAM: the 800x480 framebuffer is 48 KB, so OFFLINE_QUEUE_SIZE is 32 and
MAX_CONTACTS 250 -- with the stock limits UiCore's heap allocations fail
at boot and it loops.
Tested on hardware: Wio Tracker L1 Lite + GDEQ0426T82.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KxAZVAbhhYr18Dd4guTQM1
pmowandClaude Opus 5.5