power-pill/ascii-aquarium

ASCII Aquarium is firmware for the ESP32-2432S028R, a small and inexpensive touchscreen board sometimes called the Cheap Yellow Display. It turns the 320x240 screen into a live animated ASCII fish tank. The scene is not a video. The ESP32 renders it in real time: fish wander, school, turn around, change brightness, avoid each other, and chase food when you tap the screen. The tank includes animated ASCII fish in multiple character species with colors and depth shading, rising bubbles, swaying seaweed, and occasional visiting characters including an octopus and a seahorse. Tapping the screen drops food flakes that nearby fish chase down. Fish count, bubble count, seaweed behavior, visitor spawn rates, and background style are all adjustable through a touch settings menu. Background options include solid black, blue or purple gradient fades, and a randomized Spongebob-style flower backdrop. An optional on-screen clock can show the time in 12 or 24-hour format. The clock can sync to internet time over Wi-Fi. The Wi-Fi panel includes a network scanner, a saved credentials store, an on-screen keyboard, and automatic reconnection handling. Settings persist across power cycles using the ESP32's built-in storage. The firmware also supports SD card capture for saving screenshots or full frame sequences as BMP files. The easiest way to install it is through a browser-based flasher page using Chrome or Edge, which requires no local tooling. For those who prefer to build from source, the Arduino sketch and required library configuration files are included. The repository also documents an optional use with a 50 mm beam splitter cube, which creates an optical effect that makes the fish appear to float inside the glass rather than sit on a flat screen.