Super Mario Music Overview
I took a class on DSP System Development and one subject learned I found interesting was digital resonators. I made an expansion board for the DSP development kit we were using in class. The board included a 128 X 64 graphical LCD. I wrote a program that plays the outdoor music from the original Super Mario Brothers NES game and shows a simple graphic on the LCD. I had disassembled the sound engine from Super Mario Brothers so I had the source code for the music as a starting point. As part of the project, I had to also design a low pass filter to remove high frequency popping noises from the output audio stream. The issue is that the digital resonators change their frequency abruptly and cause the output audio stream to create a significant popping noise during the note transitions. The digital filter removes the popping noises. Also, an optional echo effect was added to the project.
TI Super Mario Music RepositorySuper Mario Music PCB Pictures
Super Mario Music PCB Schematics
Super Mario Music PCB Design
TI Super Mario Music Printed Parts
The Super Mario Music Printed Parts were designed in Free CAD.
Super Mario Music Printed Parts Source
Super Mario Music Firmware Source
TI Super Mario Music Sampled Audio Output
Finally, Below are recordings of the output. The first one is the audio after being passed through the low pass filter. The second one has the filter disabled and popping noises during note transitions can be heard. The third one has the echo feature active.