I like running LEDs off my Arduino and I also like listening to music, so I thought it would be nice if I could give my Arduino pitch perfect hearing then we could make the LEDs do some neat stuff.
I found these audio spectrum analyzer chips that are used in car stereos, so I've whipped up a shield and hooked it all up to an array of LEDs. This is all running on an Arduino, no PC connected. In fact the Arduino is not even working that hard.
- A 3.5mm Audio in connector for input.
- Another 3.5mm connector for output to your speakers/stereo.
- 7 Band real time spectrum analyzer (Stereo!) 63Hz, 160Hz, 400Hz, 1KHz, 2.5KHz, 6.25KHz, 16KHz
- Only uses 2 digital pins and one analog.
For this example the LEDs are using 2 digital pins.
I'm only using the 5 lowest frequency bands here, I'll make a bigger array soon.
I've applied some automatic gain/attenuation to keep the display interesting and prevent it maxing out on noisy tracks.
This could be used for other types of audio analysis. Voice ID or audio fingerprinting may be possible.
I'll have some shields ready in 3 weeks time, I'll post back here when they are good to go.