dangernoodle-io / breadboard / 25269923167

100%

push

github

jae/bb display ili9341 fixes (#187)

* fix(bb_display): arduino ili9341 probe + init + pixel-write correctness

three protocol bugs in the arduino ili9341 backend that would have
prevented any real ili9341 panel from working — found while trying
to drive a seeed 2.8" tft touch shield (turned out to be parallel
st7781r, but the bugs are real). references adafruit_ili9341 (bsd)
and the ili9341 datasheet rather than the previous handwritten
guesses.

probe (rddid 0xd3):
- was raising cs between cmd and read, which resets the panel's
  read pointer. now a single cs-low transaction.
- was using the 40 mhz write clock; ili9341 reads max ~10 mhz per
  datasheet. dedicated 5 mhz read SPISettings.

init:
- was a 6-command stub (swreset/dispoff/colmod/madctl/slpout/dispon).
  panels need power control, vcm, frame rate, and gamma to actually
  drive pixels. replaced with the canonical adafruit-derived sequence.

pixel writes (clear/blit):
- set_addr_window ended with send_cmd(0x2c) which raises cs, then
  the caller dropped cs again and sent pixels — many ili9341 boards
  cancel the write on that cs glitch. now caset+paset+ramwr+pixels
  is one cs-low batch.

new opt-in board hooks:
- BB_DISPLAY_ILI9341_TRUST: when defined, probe attempts the read
  for diagnostic logging but accepts the backend regardless of the
  result. for shields where the panel's sdo isn't routed to the
  host (touch chip steals miso, etc.).
- BB_DISPLAY_SHIELD_IDLE_CS_PINS: comma-separated pin list held
  high during init, so sibling devices on a shared spi bus (touch,
  microsd) don't drive miso during our reads.

371 host tests pass; r4_wifis3 + the other five smoke envs build
green. validated on the bench against the seeed shield only at the
"backlight + spi traffic visible" level — no positive pixel-paint
verification because that shield is parallel-bus.

* docs(smoke): note that the seeed 5a12 shield is parallel st7781r

discovered while testing the arduino ili9341 backend on r4 — th... (continued)

336 of 336 branches covered (100.0%)

Branch coverage included in aggregate %.

557 of 557 relevant lines covered (100.0%)

483.9 hits per line