I have been researching projectors on Amazon and identified the Vankyo Burger 101 as a compact and flexible display option.
Also, I was working on the actual Software – my idea of the Sudoku solver is one which takes JSON input, solves puzzles via backtracking, and enables user interaction through GPIO buttons or a CLI. The core algorithm employs backtracking to recursively fill in missing values while ensuring valid placements according to Sudoku rules. The software maintains a move history stack to track user inputs, allowing for easy undo functionality. A keyboard or potentially for sake of testing, CLI interface enables direct input. In theory, the software also logs each move to prevent invalid inputs and help users navigate back to previous moves. I believe that the basic skeleton of the program should work in this way, and I will potentially be adding features as needed going forward.