Robot solves Sudoku puzzle

Lego Mindstorms are futuristic toys for creative kids. But who knew these DIY robots can get creative themselves and solve puzzles? Swedish programmer Hans Andersson bought a programmable Mindstorms NXT kit for his two daughters and then began tinkering with it himself. The result: a toy that can autonomously solve Sudoku puzzles in what looks like a matter of minutes. The Sudoku Solver scans the entire puzzle with a light sensor before determining the missing digits in each square. Its computer performs image processing with a thresholding algorithm to make sense of the sensor data. Recognizing the existing numbers in the puzzle seems to be the most difficult part of the process.