I haven't found the 4017 counter but in a store nearby they have available the 4020. Can I use that IC instead of the 4017? Do I need to modify significatively the schematic above?

Thanks!

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-GaNdAlFpR

 

Hi guys,

This really would be a 'cute' project for a little 8-pin PIC ($1.60 USD)... The LEDs are multiplexed using the N(N-1) scheme and could be scanned one column at a time (from schematic point of view) for decent brightness at a 20% duty cycle and a >100-Hz refresh rate using a Timer 2 interrupt routine... Use high efficiency low current LEDs (5-ma) and you could probably run the thing off a couple AA batteries for a good length of time and the hardware couldn't get much simpler; an 8-pin PIC, 6 resistors, a 0.1-uf bypass cap', and up to 20 low current LEDs... Pretty cool -- yes, no, huh?

Regards, Mike

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led_chaser.jpg (61.7 KB, 162 views)

 

No, you can't use 4020 to replace 4017.

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L.Chung