Switch-Access Scanning Simulator (2D)

This 2D simulator models switch-access scanning, the assistive input method that lets someone who cannot point or tap reliably operate a touchscreen using a single physical switch — the same technique behind iOS Switch Control, Android Switch Access and AAC communication boards. A grid of cells is auto-highlighted row by row (or cell by cell in linear mode) on a fixed timer; pressing the switch at the right moment locks in a row, then a column, then the cell. This version adds a switch-reliability model: real hardware switches (sip-puff sensors, blink detectors, oversized buttons) don't register every press, so a misfire is silently ignored and the scan continues past your intended target, exactly like it would for a real user. Adjust the scan interval, grid size and switch reliability to see how row-column scanning's expected step count — (R+1)/2 + (C+1)/2 — stays far below linear scanning's (N+1)/2 as the grid grows, and try to beat the timer yourself to feel how dwell time and hardware reliability trade off against selection accuracy.