Re: Controlling hundreds of LEDs

From: nospam (nospam_at_nospam.invalid)
Date: 12/22/04 

Date: Wed, 22 Dec 2004 04:03:23 +0000

Danny T <danny@nospam.oops> wrote:

>nospam wrote:
>
>> So for a 348 LED display you need 3 A6276ELW chips, 8 suitable P channel
>> MOSFETS, something like a 74HC4051 to drive them and a (big if you want
>> bright) 5v power supply.
>
>I've had a quick look at the data sheets, and 16 pin output would
>certainly require less chips, but I don't understand what MOSFETs are,
>or what(/how) to use the 74HC4051 for :-\
>
>Daisy-chaining loads of 595's (or 74HCT259's as suggested in the .basic
>group) looks easy - are there any advantages/disadvantages to the method
>you suggest over this?

Yes. Driving 384 LEDs requires 4 chips and 8 3 pin transistors (MOSFETS)
instead of 48 chips and 384 resistors. Depending on how you want to
physically arrange the LEDs it can reduce the required wiring by a factor
of 8 also.

Search the web for LED, matrix, and multiplex. You should something that
gives you the idea.

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