This is a small project I developed in 2019, during my studies in Electrical & Computer Engineering @ University of Patras.
It uses components in order to digitize an analog signal, process it using LabVIEW (unfortunately required to use for my class), and then output it to an Arduino Uno, which then controls an LED 8x8 array in order to display the spectrogram of the input audio signal.
The general architecture of the system is shown below:
In summary:
- The NI USB-6001 Analog-to-Digital Converter is used to digitize the analog electrical signal
- The digitized signal is then processed in a PC using LabVIEW.
- The DC component is filtered out.
- Calculates the signal's spectrum using Fast Fourier Transform.
- Quantizes the spectrum into 8 integers representing the maximum component detected in each of 8 different equal ranges (frequencies 0-fs/2).
- Sends those 8 intergers to an Arduino Uno using the serial port.
- The Arduino then displays the quantized spectrum in a 8x8 LED Array using the MAX7219 shift register and the LedControl library.
The project report (written in modern Greek) can be found here. It contains all the necessary information about connections and explains the spectrum quantization logic in detail.
The Arduino half of the system can be tested using a simple .wav file, fed through LabVIEW. I have provided 2 audio files I used while testing the system in the test_wavs folder.
NOTE: The input analog signal should be properly filtered using an analog Low Pass Filter, in order to avoid aliasing.