Key Switches

Key switches are precision electromechanical components designed to detect and register user input through physical actuation. In keypad matrix configurations, they function as individual contact points arranged in a grid pattern (rows and columns) to minimize wiring. When a key is pressed, the switch mechanism closes an electrical circuit, sending a signal to the controller for decoding. These switches are engineered for durability, tactile feedback, and reliable electrical contact, with variations including membrane, mechanical, and dome types. They are critical for translating mechanical force into digital signals in human-machine interfaces.

Key switches operate on a simple make-or-break contact principle. In a keypad matrix, switches are arranged in a grid where each row and column line is connected to multiple switches. When a key is pressed, it physically closes the contact between its specific row and column lines, creating a conductive path. The controller scans the matrix by sequentially activating rows and reading columns to detect which switch is closed, identifying the key pressed through its unique row-column intersection. This matrix design reduces the number of required I/O pins compared to individual wiring for each key.