I’m going to explain how to create a processing programme in this Instructable that analyses sound on your device and sends data to an Arduino that controls an LED matrix to illustrate the spectrum analysis.
I’m going to explain where to buy supplies, explain the appropriate
coding and wiring and include sample applications that can be modified.
I’m going to use an Arduino Nano and a 32×16 LED Matrix.
Step 1: Required Materials/Software and Where to Get Them
The required materials are:
1) An Arduino(doesn’t really matter which version/variant)
2) LED Matrix (for this Instructable, I use a 32×16 bicolor matrix, but any matrix should work)
3) A driver chip if your LED matrix doesn’t have them integrated, I will be explaining this in more depth.
Inexpensive LED Matrices: Sure Electronics: http://stores.ebay.com/Sure-Electronics
The display I use: http://www.ebay.com/itm/P4-32X16-RG-Bicolor-LED-3mm-Dot-Matrix-Unit-Board-/350527814626?
Step 2: Wiring
Step 3: Driver Chips
For a 8×8 matrix, I would suggest getting a MAX7219. This driver chip can control a 8×8 matrix, or 8, 7-Segment displays and only use 4 pins plus a +5V and GND. The MAX7219 can also be daisy chained to another 9 drivers. There are other driver chips available, but the MAX7219 has an Arduino library in existence which makes coding easier for beginners.
For more details: Arduino / Processing Audio Spectrum Analyzer