A real-time audio waveform visualizer targeting the Xilinx Spartan-7 FPGA.
- The design targets the Digilent Arty S7-50 FPGA board, which features an Xilinx Spartan-7 FPGA
- The Digilent PMOD I2S2 was used to receive and transmit I2S data
- The Digilent PMOD VGA was used to display the waveform out of VGA
- Vivado was used to synthesize and implement the design
- A combination of XSim and Icarus Verilog were used to simulate the design
- All testbenches and custom IP were designed in Verilog
- A golden-model of the design was developed in Python, which was used to generate expected inputs and outputs to verify the behaviour of the design
- Connect the PMOD I2S2 Line In to a 3.5mm audio input device (e.g. a PC or smartphone)
- Connect the PMOD I2S2 Line Out to a 3.5mm audio output device (e.g. speakers or headphones)
- Connect the PMOD VGA to a VGA-capable monitor
- Download the bistream to the FPGA board using Vivado, which, once complete, will display the following waveform:
- At this point, audio can be played using the input device, and the time-domain waveform of the audio will be displayed on the monitor.
- To change the colour of the waveform or background, open a serial terminal (e.g. puTTy) on the input device
- Input "r", "g", or "b" to select the channel to edit. The RGB LEDs on the board will light up in the colour you are currently editing:
- Choose an intensity, specified as a hexadecimal digit. Valid values range from 0 to f:
- Choose either "b" to change the background, or "w" to change the waveform colour:
- The same steps can be followed to edit the colour of the waveform as well
- Play audio and watch as the waveform changes throughout the song! You can also edit the colours while audio is playing.
Some of my personal favourite colour schemes are
| Background | Waveform | Description |
|---|---|---|
| (0, 2, 6) | (f, f, f) | A white waveform on a blue background |
| (2, 0, 3) | (f, 0, 9) | A neon-pink waveform on a dark-purple background |
| (1, 7, 0) | (f, f, 0) | A yellow waveform on a dark-green background |
- Displaying the Fourier Transform of the audio data as well
- A reverb effect to simulate playing audio in small, medium, and large rooms
- Using the Digilent PMOD SD and SPI to play audio files stored on an SD card
- Adding a MEMS microphone to display incoming sound waves