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Topic: led driver (Read 1 time) previous topic - next topic

chris


this one:
http://arduino.berlios.de/index.php/Tutorial/LEDDriver

How many 4794 chips could the Arduino board handle?

Does the 4794 support 8 LEDs?

Thanks

David Cuartielles

Hej,

the 4794 can handle 8 simultaneous outputs, but you can daisy chain it and add more chips in series. We have a project here now with 64 double-coloured LEDs at once.

On the other hand, there is another LED driver, from Maxim, the 7219 that handles 64 LEDs at once, but that is more complicated to wire.

/David

chris


Thats very interesting indeed. Do you know anywhere online to buy this chip?

Do you have any documentation online about how to daisy chain it?

I have a 7219 that I am using for an LED matrix, although just starting.
http://www.flickr.com/photos/pixelsumo/68040275/


Chris

David Cuartielles

Hej,

If you are in Englad, you could get it from http://www.elfa.se , they sell over the net and accept credit card. Also Farnell and Digikey may have it, but I haven't searched there.

The datasheet is available in our web repository:

http://webzone.k3.mah.se/projects/arduino-workshop/upload/default.asp?folder=28

/David

Flat Stanley

Hi David,

is there a more generic name for the 4794??

i'm trying to find an equivalent chip from RS (as I have an account with them) (http://rswww.com) but when i search for led drivers, i don't find the right sort of chip

Is it a multiplexer?? or ...???

Thanks a lot

Jonathan

my hobby --  www.jonathanbryan.com

my life --  www.ifranks.com  [link]www.silver-collector.com[/link] [link]www.da

David Cuartielles

Hej,

the proper name for this component is actually: 8-stage shift-and-store register LED driver, HEF4794B. But in a superficial search through your provider's website I couldn't find it.

However there are some alternatives you should be able of using any other LED drivers, or shift registers.

/David


David Cuartielles

Hej again,

actually the:

8-digit LED display driver,MAX7219CNG
RS Stock no: 311-473

will be able of driving up to 64 LEDs with one single resistor ;-)

This one will make the magic for you,

/David

Flat Stanley

Thats great!

i'll report on my experience of using the chip!

Thank You!

Jonathan

my hobby --  www.jonathanbryan.com

my life --  www.ifranks.com  [link]www.silver-collector.com[/link] [link]www.da

boppyer

or you can get one of these for testing:

http://www.nexusmachines.com/Products/displays/bxxcdm.htm

they are slightly expensive but good.

cheers

boppyer:-)

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