Difference between revisions of "How to drive many leds with a few io-pins"

Revision as of 22:53, 30 August 2006

For any straightforward led matrix you can double the number of leds by using tri-state switching and parallel reversed leds.

The 12F509 Knight Rider uses this technique to switch 12 leds with only 5 I/O pins (the 6th pin is input only, so 5 is the max for the 12F509).

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−	For any straightforward led matrix you can double the number of leds by using tri-state switching and parallel reversed leds. ~~This means i.e. that~~ with only 5 I/O pins ~~you can switch 12 leds~~.	+	For any straightforward led matrix you can double the number of leds by using tri-state switching and parallel reversed leds.
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		+	The 12F509 Knight Rider uses this technique to switch 12 leds with only 5 I/O pins (the 6th pin is input only, so 5 is the max for the 12F509).