st7796: enable display inversion (INVON) like the st7789 init - #604
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st7796: enable display inversion (INVON) like the st7789 init#604bitcoin3us wants to merge 1 commit into
bitcoin3us wants to merge 1 commit into
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Without INVON the ST7796 IPS panels render everything in negative. Found on the Waveshare ESP32-S3-Touch-LCD-3.5: the inverted UI passed for a dark theme during bring-up, and only camera preview photos made the inversion obvious. Hardware-verified: sending INVON live flips the panel to correct colors, and a firmware built with this init renders correctly from boot. The st7789 init already sends INVON for the same reason. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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The st7796 init never sends INVON (0x21), so ST7796 IPS panels render everything in negative. The st7789 init already sends INVON unconditionally for exactly this reason; this brings st7796 in line.
Found while bringing up the Waveshare ESP32-S3-Touch-LCD-3.5 in MicroPythonOS (MicroPythonOS/MicroPythonOS#280): the inverted UI passed for a plausible dark theme during initial testing, and only became obvious once a camera preview looked like a photographic negative. Hardware-verified both ways on that board: sending INVON to the live panel flips it to correct colors instantly, and firmware built with this init renders correctly from boot.
Caveat: ST7796 also ships on non-IPS TN modules that would not want inversion. This PR mirrors st7789's unconditional choice for consistency, but if you'd prefer it settable (e.g. an
invertconstructor flag on the driver, defaulting to the current behavior of whichever family), I'm happy to rework it that way — the same flag would arguably benefit st7789 too.🤖 Generated with Claude Code