无线终端中低功耗键盘的设计

low-power dissipation keyboard in wireless terminals, based on A/D converter method, is practiced in this paper. Most wireless terminals based on microcontroller have an on-board small keyboard and various switches, using a large number of microcontroller I/O pins then leaving small number of pins available for other uses. The designed keyboard employs only single I/O pins and saves the power dissipation effectively. The power dissipation behaviors of two keyboards, one is based on scanning method and another on A/D converter method, was compared and analyzed. The keyboard has been applied in a practical system.