da7f107273
* POV Display usermod this usermod adds a new effect called "POV Image". To get it to work: - read the README :) - upload a bmp image to the ESP filesystem using "/edit" url. - select "POV Image" effect. - set the filename (ie: "/myimage.bmp") as segment name. - rotate the segment at approximately 20 RPM. - enjoy the show! * improve file extension checks * improve README, remove PNGdec reference, clean usermod * restrain to esp32 platform + reduce memory footprint with malloc
48 lines
2.6 KiB
Markdown
48 lines
2.6 KiB
Markdown
## POV Display usermod
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This usermod adds a new effect called “POV Image”.
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###How does it work?
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With proper configuration (see below) the main segment will display a single row of pixels from an image stored on the ESP.
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It displays the image row by row at a high refresh rate.
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If you move the pixel segment at the right speed, you will see the full image floating in the air thanks to the persistence of vision.
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RGB LEDs only (no RGBW), with grouping set to 1 and spacing set to 0.
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Best results with high-density strips (e.g., 144 LEDs/m).
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To get it working:
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- Resize your image. The height must match the number of LEDs in your strip/segment.
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- Rotate your image 90° clockwise (height becomes width).
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- Upload a BMP image (24-bit, uncompressed) to the ESP filesystem using the “/edit” URL.
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- Select the “POV Image” effect.
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- Set the segment name to the absolute filesystem path of the image (e.g., “/myimage.bmp”).
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- The path is case-sensitive and must start with “/”.
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- Rotate the pixel strip at approximately 20 RPM.
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- Tune as needed so that one full revolution maps to the image width (if the image appears stretched or compressed, adjust RPM slightly).
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- Enjoy the show!
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Notes:
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- Only 24-bit uncompressed BMP files are supported.
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- The image must fit into ~64 KB of RAM (width × height × 3 bytes, plus row padding to a 4-byte boundary).
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- Examples (approximate, excluding row padding):
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- 128×128 (49,152 bytes) fits.
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- 160×160 (76,800 bytes) does NOT fit.
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- 96×192 (55,296 bytes) fits; padding may add a small overhead.
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- If the rendered image appears mirrored or upside‑down, rotate 90° the other way or flip horizontally in your editor and try again.
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- The path must be absolute.
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### Requirements
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- 1D rotating LED strip/segment (POV setup). Ensure the segment length equals the number of physical LEDs.
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- BMP image saved as 24‑bit, uncompressed (no alpha, no palette).
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- Sufficient free RAM (~64 KB) for the image buffer.
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### Troubleshooting
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- Nothing displays: verify the file exists at the exact absolute path (case‑sensitive) and is a 24‑bit uncompressed BMP.
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- Garbled colors or wrong orientation: re‑export as 24‑bit BMP and retry the rotation/flip guidance above.
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- Image too large: reduce width and/or height until it fits within ~64 KB (see examples).
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- Path issues: confirm you uploaded the file via the “/edit” URL and can see it in the filesystem browser.
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### Safety
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- Secure the rotating assembly and keep clear of moving parts.
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- Balance the strip/hub to minimize vibration before running at speed. |