Reddit user Krukerfluk has created an awesome DIY digital clock using 144 x seven segment displays, combining them to create a larger LED display powered by an Arduino Nano.

He made his own. The easy part consists of Neopixels, an Arduino Nano and a DS3231 Real Time Clock. The hard part consists of Plasticard and a polymorph diffuser.

Inside the boxy blue base is an Arduino Nano, a DS3231 real-time clock module, and a perfboard full of transistors for switching the LED strips inside the segments.