Although it seems the default display strategy for most Arduino projects is to use an LCD display, there still remains a need for numeric LED displays - they're cheap, robust and can be read in light levels that can often wash out an LCD. However using them without external shift registers can burn up your digital I/O pins quickly. Therefore this tutorial by Instructables user 'edl1' will be of interest. They have explained the process of "Charlieplexing" - or using multiplexing to reduce the number of required output pins to drive four seven-segment LED displays.
The theory and practice is explained and demonstrated - and this method also translates well for making LED matrices. So click here to get started, and for more, we're on twitter and Google+, so follow us for news and product updates as well.
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