802 IEEE Devil Nyan Cat VGA
802 : IEEE Devil Nyan Cat VGA
- Author: Daniel García
- Description: VGA Nyan Cat with synchronized audio and a real-time color mutation toggle (Devil Mode).
- GitHub repository
- Open in 3D viewer
- Open in VGA Playground
- Clock: 25175000 Hz
Devil Nyan Cat VGA
How it works
This project, developed at the Cosmic Rays Group (UMSA), implements a "cursed" version of the classic Nyan Cat in hardware. It generates a 640x480 @ 60Hz VGA signal and synchronized audio.
Visual Engine
The "Devil" effect is achieved through a real-time color transformation pipeline:
- Green Inversion: The green channel is bitwise inverted (
~g_src), shifting the palette towards toxic tones. - Blue Suppression: The blue channel is forced to zero (
6'b0), resulting in an aggressive red-orange spectrum. - Dithering: Uses a 2x2 Bayer matrix for better color rendition on the 2-bit per channel Pmod.
Audio Synthesis
Sound is generated from pre-calculated note tables, split into melody and bass square waves with exponential decay envelopes, processed through a sigma-delta DAC.
How to test
Set clock to 25.175MHz, provide a reset pulse (rst_n), and observe the corrupted transmission.
External hardware
- TinyVGA Pmod for video on
uo_out[7:0]. - 1-bit sound on
uio_out[7], compatible with Tiny Tapeout Audio Pmod or a simple RC filter.
Author: Daniel Roberto Garcia Miranda (Dani3184)
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | Devil Mode (0=Normal, 1=Devil) | R1 | unused |
| 1 | unused | G1 | unused |
| 2 | unused | B1 | unused |
| 3 | unused | VSYNC | unused |
| 4 | unused | R0 | unused |
| 5 | unused | G0 | unused |
| 6 | unused | B0 | unused |
| 7 | unused | HSYNC | Audio PWM output |