Firmware

Keyboard Debounce Filters Contact Bounce

A single physical key press does not always create one perfectly clean electrical transition. In many mechanical switches, metal contacts meet and settle over a short interval. During that interval, the electrical state can change several times before becoming stable. Keyboard electronics have to separate that brief contact behavior from deliberate repeated presses. The filtering process is commonly called debounce. A switch can change state several times while settling A basic mechanical key switch acts as an electrical contact. Pressing the key moves parts of the switch until conductive surfaces meet. Releasing it separates those surfaces again.