Tune SSD1677 LUTs for PaperMono text/quality modes - #272
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lovyan03
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This reverts merge commit 1f481eb (PR #272, commit 3bcad74). The retuned epd_quality waveform is not DC balanced: every gray level nets +58 to +72 frames of VSH1 per refresh, whereas the previous waveform nets zero for all four levels. On the panel this shows up as sticking after repeated quality refreshes, and the white level ends up slightly gray. The new epd_text waveform also reduced that mode from four gray levels to two, dropping light details in images. Withdrawn in agreement with the author. The issue that motivated the change (white areas developing dark speckles after prolonged use, which clear on the next refresh) will be investigated separately.
lovyan03
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Revert "Tune SSD1677 LUTs for PaperMono text/quality modes" (#272)
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Summary
Updated the SSD1677 waveforms used by the
epd_textandepd_qualityupdate modes.Preliminary Observations
The updated waveforms still require further stability and long-term refresh testing.
The white level in the
epd_qualitymode appears slightly gray compared with the white level in the existingepd_fastandepd_fastestmodes. As a result, the boundaries between regions refreshed by different modes can be visibly distinguished.The white levels of the different refresh modes may require further adjustment to provide a more consistent display appearance.