A 60-LED ring driven by an Arduino Nano with a DS3231 backing it up — the result is an analog-style clock that drifts less than two minutes a year, survives power outages, and lets you reskin the colour scheme in a few lines of code. Whole

A pocket-sized distance meter for under €10 in parts, built in an evening. Point it at a wall, read centimetres on a 0.96″ OLED, and learn the two most-used peripherals in beginner Arduino work — a digital pulse-timed sensor and an I²C disp