The last missing piece of hardware to complete the MagicHat is the mouth

The mouth will be a simple VuMeter that continously read the line output from the USB audio card and switch on LEDs accordingly

LEDs will be switched on from the center to the sides to give the impression that the mouth is more open when the sound is louder

 

Here is the circuit schematic

 

18 - Mouth.png

 

and here is the flowchart of the code that switches on and off LEDs

 

18 - The mouth.png

 

NOTE: (threshold1 < threshold2 < threshold3 < threshold4)