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LED tiles: Difference between revisions
From London Hackspace Wiki
Added cable, comment about shift register
(Added Getting Started section with information and sample Arduino code) |
(Added cable, comment about shift register) |
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As someone has explained elsewhere the panel displays one row group at a time, so it's necessary to cycle them in equal proportions to get a full image. The row addressing performs two functions, to select the row group that's both energised and into which data will be clocked. Note that it appears that you can select a row and clock data into it, but that data is held but not transferred to the display until you toggle the latch input even if you change to a different row group. In this way it seems possible (though not yet tried) to build up in the shift register the next image to be displayed a small amount at a time to maintain a good refresh rate, and then transfer it to the display by latching. | As someone has explained elsewhere the panel displays one row group at a time, so it's necessary to cycle them in equal proportions to get a full image. The row addressing performs two functions, to select the row group that's both energised and into which data will be clocked. Note that it appears that you can select a row and clock data into it, but that data is held but not transferred to the display until you toggle the latch input even if you change to a different row group. In this way it seems possible (though not yet tried) to build up in the shift register the next image to be displayed a small amount at a time to maintain a good refresh rate, and then transfer it to the display by latching. | ||
The shift register is not cleared by the latching operation so you can add to a row and latch again. To clear a row it's necessary to send 288 'black' pixels to it. | |||
A suitable ribbon cable is part CN16494 from CPC at around £3. http://cpc.farnell.com/1/1/110292-amphenol-fc16600-0-lead-2-54mm-f-f-600mm-16way.html | |||
Simple Arduino code example: | Simple Arduino code example: | ||
