A Nintendo DS homebrew application written in C that doubles as an interactive digital business card. The top screen runs a live, auto-looping Counting Sort (O(n)) visualization while the bottom screen displays contact and academic information.
Runs on melonDS emulator and tested on real Nintendo 3DS XL hardware via homebrew.
| Top Screen | Bottom Screen |
|---|---|
| Animated Counting Sort bars (randomize → sort → repeat) | Static business card with contact info |
Build the
.ndsfile and open it in melonDS to see it in action.
| Area | Details |
|---|---|
| Low-level C | Manual memory management (malloc/calloc/free), raw pointer arithmetic, pixel-level buffer writes |
| Embedded graphics | Direct VRAM writes, framebuffer mode, 8-bit paletted BG layers via libnds |
| DMA transfers | dmaCopy for zero-CPU-overhead blits of image data and pixel buffers to VRAM |
| ARM9 architecture | Cross-compiled for ARMv5TE (arm946e-s) targeting the Nintendo DS ARM9 core |
| VBlank sync | swiWaitForVBlank() for tear-free 60 FPS rendering |
| Algorithm visualization | Counting Sort implemented step-by-step with per-frame screen updates mid-sort |
| Toolchain | devkitARM + libnds + grit (image conversion) + GNU Make, built on Linux (WSL) |
| Build system | Recursive Makefile with separate ARM9 target, object file management, and asset pipeline |
- 64 bars are randomized with random heights and colors.
- Counting Sort runs, but pauses on every placement to redraw the screen — giving a smooth, step-by-step animation.
- After sorting completes, the bars are re-randomized and the loop restarts.
The sort itself runs in O(n) time. The visual slowdown is intentional — a swiWaitForVBlank() call inside the sort loop forces one frame per placement, making each step visible.
A PNG business card image (zaidCard.png) is converted at build time by grit into an 8-bit paletted bitmap. At runtime, dmaCopy blits the pixel data and palette directly into sub-screen VRAM, displaying a crisp static image with no CPU overhead.
DS_Business_Card/
├── Makefile # Top-level recursive build
├── IMG_7940.jpg # Photo of the project running on real hardware
└── arm9/
├── Makefile # ARM9 devkitARM build rules
├── source/
│ └── main.c # Core application logic
├── include/
│ └── font8x8_basic.h
└── data/
├── zaidCard.png # Business card image
└── zaidCard.grit # grit config: 8bpp paletted bitmap, 256-color palette
- devkitPro with
devkitARMandlibnds ndstool(included with devkitPro)- GNU Make
- Linux / WSL terminal
git clone https://github.com/zaidahmad16/DS_Business_Card.git
cd DS_Business_Card
export DEVKITARM=/opt/devkitpro/devkitARM # adjust to your install path
makeThis produces arm9/arm9.nds. Open it in melonDS or flash it to a homebrew-enabled DS/3DS.
make clean- Emulator: Open the
.ndsfile in melonDS - Real hardware: Copy to an SD card and launch via a homebrew loader (e.g., TWiLight Menu++) on a Nintendo DS/3DS
| Tool | Details |
|---|---|
| OS | Ubuntu via Windows Subsystem for Linux (WSL2) |
| Compiler | devkitARM (GCC cross-compiler for ARM) |
| Graphics lib | libnds |
| Image converter | grit |
| Build tool | GNU Make |
| Test targets | melonDS emulator + Nintendo 3DS XL (homebrew) |