Soldering DIY Nixie Tube Clock

This is a hands-on DIY digital clock kit requiring soldering assembly, designed for electronics enthusiasts. Dimensions are 140 × 32 × 40 mm, with a clear transparent plastic case and DC 5V USB power input. Built around the IAP15W413AS MCU and DS1302 RTC chip, it drives four nixie-style LED tubes with full colour flexibility: each tube can be set to one of four colours individually, or configured for coordinated cycling, full-random patterns, or per-tube random transitions. Time format supports both 12-hour and 24-hour systems, with automatic weekday detection and date tracking starting from 1 January 2019 (reset default). Temperature readout is available in Celsius (default) or Fahrenheit. Three alarm channels are included — Alarm 1 activates daily at 7:00 by default; Alarms 2 and 3 are pre-configured but disabled out-of-box. Alarm scheduling allows Mon–Sun or Mon–Fri operation. Hourly chime runs 07:00–21:00 by default and can be toggled off. Three melodies — 'To Alice' (default), 'Ode to Joy', and 'Spanish Bullfighter' — play on alarm and chime events. Display modes rotate through time-only (default), time+temperature, time+date+week, and time+date+day+date. Brightness offers auto-dimming or three fixed levels. Time correction function enables periodic calibration to offset long-term drift.