Nixie projects look really cool and old fashioned. If you are tired of LCDs then take a look at this amazing work. It consists of 81 Nixie tube what makes 9×9 display matrix. Nixies are controlled by Arduino platform while cursor is navigated by two knobs. Number is entered via simple keypad. This Sudoku solver also has a recursive Sudoku solving algorithm which can solve Sudoku’s by itself. It’s really fun to look at action itself.