Glow Garden started as a late-night experiment: what if a plant could tell you when it wanted attention? We wired a capacitive touch sensor directly into the soil, so a gentle press on the dirt triggers a slow, breathing pulse through a ring of addressable LEDs embedded in the pot rim.
The enclosure is 3D-printed in two halves — an inner liner to hold the plant and soil, and an outer shell with a diffusion channel for the LEDs. We painted the outside with a clay-textured spray and the result looks almost natural on a desk until it starts glowing.
The Arduino Pro Mini sleeps between touch events to keep battery life reasonable. We have the pot running on two AA batteries in the Engineering common room and it's been going for three weeks without a change.