Three problems surfaced during the first 13.3" end-to-end run:
1) LittleFS IntegerDivideByZero on 200 → write /img.bin. Cause: the
~3.5 MB SPIFFS in default_16MB.csv can't fit three 960 KB setup
screens + a 960 KB cached image (~3.84 MB). Switching to a custom
partitions_13e6.csv with 24 MB LittleFS on the 32 MB flash.
2) Yellow wash across the panel on long SPI bursts. Cause: SPI DMA
from a PSRAM-backed scratch buffer hits a cache-coherency window —
the CPU's writes hadn't reached PSRAM yet when DMA read it. Push
each half in 8 KB chunks through an internal-SRAM (DMA-coherent)
scratch, and drop the bus clock to 4 MHz to match the 7.3"
production speed.
3) Bootstrap window (no image yet) was deep-sleeping for 15 s between
polls — each cycle a ~5 s ROM-boot + Wi-Fi reconnect, so the user
waited ~20 s × N retries between scanning the setup QR and seeing
their first photo land. Now normal_operation_impl returns early
during bootstrap and main.cpp's normal_operation loops with a
2 s delay, keeping Wi-Fi up. Once the first image arrives, the
normal scheduled deep sleep takes over.
Also fixes a related bug Matt called out: a transient TLS hiccup
during bootstrap was hitting the 5xx fallback path and painting a
full yellow fill over the green setup QR, leaving the user with
no claim path. Criterion is now "does /img.bin exist?" (panel has
something worth showing with a border) rather than "is currentImgId
set?", so a fresh device with no cached image preserves the setup
screen through transient network errors.
Diagnostic prints in the panel driver + [op] start/code lines in
normal_operation_impl that proved invaluable during bringup; leaving
them in for now. Tests updated for the new bootstrap semantics
(deep sleep no longer arms on bootstrap-cycle 204/404/5xx); 43/43
native tests pass, 7.3" production build stays byte-identical.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
