LED tiles - Revision history

Marcbarto: remove a members' name as tile as been collected

2016-03-07T18:57:33Z

remove a members' name as tile as been collected

← Older revision		Revision as of 18:57, 7 March 2016
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	* 10. Pingless		* 10. Pingless
	* <strike>11. Asc (2 please)</strike>		* <strike>11. Asc (2 please)</strike>
	* 12. James Cadman		* <strike>12. James Cadman</strike>
	* <strike>13. Henry Best</strike>		* <strike>13. Henry Best</strike>
	* <strike>14. Martin Goodman</strike> (2 please)		* <strike>14. Martin Goodman</strike> (2 please)

Memargolis@gmail.com: Added test sketch

2016-02-11T08:30:56Z

Added test sketch

Show changes

JJ: Fix code block formatting

2016-02-08T23:52:26Z

Fix code block formatting

← Older revision		Revision as of 23:52, 8 February 2016
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	Simple Arduino code example:		Simple Arduino code example:

	<~~code~~>		<pre>
	digitalWrite(pinOE, LOW);		digitalWrite(pinOE, LOW);

Line 155:		Line 155:
	digitalWrite(pinLAT, LOW);		digitalWrite(pinLAT, LOW);

	</~~code~~>		</pre>

	The pixel writing could be made much faster using direct port operations, particularly with a port dedicated to the tile interface - one write with clock low to set the R G B values and the next holding the values with clock high - probably of the order of 50 times faster than the code above.		The pixel writing could be made much faster using direct port operations, particularly with a port dedicated to the tile interface - one write with clock low to set the R G B values and the next holding the values with clock high - probably of the order of 50 times faster than the code above.

JJ: Added cable, comment about shift register

2016-02-08T23:50:31Z

Added cable, comment about shift register

← Older revision		Revision as of 23:50, 8 February 2016
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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:

JJ: Added Getting Started section with information and sample Arduino code

2016-02-07T16:45:46Z

Added Getting Started section with information and sample Arduino code

← Older revision		Revision as of 16:45, 7 February 2016
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	Glen Akins has some extremely good technical detail here: http://bikerglen.com/projects/lighting/led-panel-1up/		Glen Akins has some extremely good technical detail here: http://bikerglen.com/projects/lighting/led-panel-1up/

			== Getting Started ==

			Some key information and pointers for anyone getting started with a tile and a basic microcontroller like the Arduino (we used a Mega 2560), Raspberry Pi, BeagleBone etc.

			The OE (Output Enable) pin is misleadingly named as it's really Output Inhibit or Blanking, having to be pulled low to enable the LEDs. All other inputs are active high.

			The panel is organised as six row groups that are interlaced both vertically and horizontally (see illustration) to minimise flicker. Each group contains 288 pixels organised in a shift register so new data shifts along the row group in the order shown.

			[[File:Hackspace LED Tile addressing.png\|thumbnail\|48 x 36 LED Tile Addressing Scheme]]

			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.

			Simple Arduino code example:

			<code>
			digitalWrite(pinOE, LOW);

			// select first row
			digitalWrite(pinA, LOW);
			digitalWrite(pinB, LOW);
			digitalWrite(pinC, LOW);

			For(int i=0; i<288; i++)
			{
			// set high or low value for each pixel
			digitalWrite(pinR1, R);
			digitalWrite(pinG1, G);
			digitalWrite(pinB1, B);
			// pulse the clock line to move this data into the shift register
			digitalWrite(pinCLK, HIGH);
			digitalWrite(pinCLK, LOW);
			}

			// pulse the latch line to transfer the new data to the display
			digitalWrite(pinLAT, HIGH;
			digitalWrite(pinLAT, LOW);

			</code>

			The pixel writing could be made much faster using direct port operations, particularly with a port dedicated to the tile interface - one write with clock low to set the R G B values and the next holding the values with clock high - probably of the order of 50 times faster than the code above.

JJ: Added link to Greg Akins technical info page

2016-02-07T16:31:22Z

Added link to Greg Akins technical info page

← Older revision		Revision as of 16:31, 7 February 2016
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	You can find his mailing list post here: https://groups.google.com/d/msg/london-hack-space/Gs4_P4Je1gw/HFshYAzhEQAJ		You can find his mailing list post here: https://groups.google.com/d/msg/london-hack-space/Gs4_P4Je1gw/HFshYAzhEQAJ

			Glen Akins has some extremely good technical detail here: http://bikerglen.com/projects/lighting/led-panel-1up/

Tobycatlin at 16:50, 3 February 2016

2016-02-03T16:50:20Z

← Older revision		Revision as of 16:50, 3 February 2016
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	PIXELS		PIXELS
	* 36 ~~x 48~~		* 48 x 36
	* Pixel Configuration SMD 3528		* Pixel Configuration SMD 3528
	* LED Type Black Diamond		* LED Type Black Diamond

Ciborg at 16:30, 3 February 2016

2016-02-03T16:30:13Z

← Older revision		Revision as of 16:30, 3 February 2016
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	* 18. Robin Baumgarten (2 if possible)		* 18. Robin Baumgarten (2 if possible)
	* <strike>19. Giac0m0 (2 if possible) </strike>		* <strike>19. Giac0m0 (2 if possible) </strike>
	* <strike>20. Bennage (2 if possible, please)		* <strike>20. Bennage (2 if possible, please)</strike>
	* 21. [[User:Detonate\|Det]] (1)		* 21. [[User:Detonate\|Det]] (1)
	* 22. [[User:Betandr\|betandr]]		* 22. [[User:Betandr\|betandr]]
	* <strike>23. Ciborg ~~(2 please)~~</strike>		* <strike>23. Ciborg</strike>
	* <strike>24.Stefan Sabo (HS07764) 2 </strike>		* <strike>24.Stefan Sabo (HS07764) 2 </strike>

Henry Best at 21:11, 1 February 2016

2016-02-01T21:11:08Z

← Older revision		Revision as of 21:11, 1 February 2016
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	* <strike>11. Asc (2 please)</strike>		* <strike>11. Asc (2 please)</strike>
	* 12. James Cadman		* 12. James Cadman
	* 13. Henry Best		* <strike>13. Henry Best</strike>
	* <strike>14. Martin Goodman</strike> (2 please)		* <strike>14. Martin Goodman</strike> (2 please)
	* <strike>15. Thomas Hill</strike>		* <strike>15. Thomas Hill</strike>

Giac0m0: /* Tiles for members */ Striked Giac0m0

2016-02-01T13:58:04Z

Tiles for members: Striked Giac0m0

← Older revision		Revision as of 13:58, 1 February 2016
Line 45:		Line 45:
	* <strike>17. Michael Margolis</strike> (2 if possible)		* <strike>17. Michael Margolis</strike> (2 if possible)
	* 18. Robin Baumgarten (2 if possible)		* 18. Robin Baumgarten (2 if possible)
	* 19. Giac0m0 (2 if possible)		* <strike>19. Giac0m0 (2 if possible) </strike>
	* <strike>20. Bennage (2 if possible, please)		* <strike>20. Bennage (2 if possible, please)
	* 21. [[User:Detonate\|Det]] (1)		* 21. [[User:Detonate\|Det]] (1)