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LED matrix in a MIDI controller?

Bekai

Jun 5, 2012
3
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Jun 5, 2012
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Hi there,

I am completely new to electronics so I apologize for my severe lack of knowledge.
I am currently trying to build a MIDI controller that works via USB. The unit consists of 13 potentiometers, 42 momentary buttons and the hard part; either 74 single color LEDs or 10 single color and 32 RGB.

At first I was looking at the Arduino Mega 2560; it has 16 analogue input pins (fine for 13 potentiometers) and 54 digital I/O pins (fine for 42 buttons) but that only leaves me with 12 pins for all the LEDs

Does anyone have any idea how I could achieve this?

I was wondering whether something like this: http://www.makershed.com/LoL_shield_for_Arduino_p/mkjr3.htm could be modified to give me just 74 LEDs and enough inputs left for the buttons?
or maybe this: http://iteadstudio.com/store/index.php?main_page=product_info&cPath=18&products_id=312 could work with RGB LEDs?

Here is a rough picture of what I intend to make, the large buttons are the ones I want 2+ colors for and the top ones only need one.
2na2q9k.jpg


As a complete novice I could just barking up the wrong tree? either way I would really appreciate some insight!

Thanks
 

Bekai

Jun 5, 2012
3
Joined
Jun 5, 2012
Messages
3
Harald, thanks for the reply!
Good to know that I could use these shields, it would be great to have programmable RGB LEDs!
If you don't mind me asking, what would the shield connect to on the arduino if not I/O pins? (apologies as this sounds like a stupid question) I am doing my best to read up on this but am finding it quite a steep learning curve with no prior knowledge to electronics...
 

Harald Kapp

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Nov 17, 2011
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I truly don't know.
But from what I can see here http://arduino.cc/en/uploads/Main/Arduino_Uno_Rev3-schematic.pdf it looks like the shield interface uses IO ports.
The important thing is that the LED controller shields use multiplexing. Thus you don't need one I/O pin per LED but less. How many depends on the details of the shield. You will have to look up that information in the shield's datasheet.

Harald
 
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