arduino, max7219 and a lot of leds

Forum 2005-2010 (read only) Hardware Interfacing
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hi everybody

i'm starting a project using a arduino board.
being completly new to the physical computing world I would very much apreciate your inputs on some questions.

I need about 1000 leds controlled individualy (1024 is perfect)
i came across a post from daniel who is making a project for the same amount of leds that answered my first question (is it possible?) :slight_smile:

for what I have read in the forum i need 16 max7219 each one controlling 64 leds. right?

since i don't want to use any kind of led matrix because I need the leds dispersed randomly in space, do i need to replicate the circuit of a matrix to control the leds? having 16 8x8 matrixs to control the leds? or can i just conect them individualy to the boards with the max7219?

how will I power this thing? external power to the arduino board?

I just need to have each leds on or off at any given moment. do you think it will be fast from the moment the software asks for a led to turn on and it being actualy on?

My arduino just arrived, can someone help me with a basic material list for the other things i am sure to need for this?

many thanks and sorry for my rough english
luis

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hi

probably everything you need to know is in two forum posts... they're linked from this page under "MAX7219"

D

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Hi Luis,

Have a look at the playground->LedMatrix section too!
http://www.arduino.cc/playground/Main/LEDMatrix
There are 2 libraries available for this topic.

Until you read up on this:

i came across a post from daniel who is making a project for the same amount of leds that answered my first question (is it possible?)

Yes

for what I have read in the forum i need 16 max7219 each one controlling 64 leds. right?

Yes

since i don't want to use any kind of led matrix because I need the leds dispersed randomly in space, do i need to replicate the circuit of a matrix to control the leds? having 16 8x8 matrixs to control the leds? or can i just conect them individualy to the boards with the max7219?

The wiring must replicate the schema of a matrix. Have a look at this picture

Taken from the LedControl-docs http://www.wayoda.org/arduino/ledcontrol/index.html

how will I power this thing? external power to the arduino board?

No, you will have to supply the max7219 with an external power-source for the leds.
You will need about 160mA for each Max7219 with 16 pices youll end up at 2.5 Amps, That will be too much
for the connectors on the arduino board!

I just need to have each leds on or off at any given moment. do you think it will be fast from the moment the software asks for a led to turn on and it being actualy on?

I have only tested 8 MAX7221 at once. The seems to be no visible delay between switching an Led on the first MAX7221 and the last one on the chain of devices.

Have fun
Eberhard

4

hi

probably everything you need to know is in two forum posts... they're linked from this page under "MAX7219"

D

Who is allowed to update this (very useful!) index ?
There are articles about the topic in the playground, too.

Eberhard

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hi Eberhard

I made it and update it, there's a link at the top of the page to suggest something to include!

D

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hi

many thanks for pointing me in the right direction!

I will be working on this project for a couple of months and will post updates on it (if you're interested)

thanks
luis

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