Variable digital control for electronic device with rotary switch control

摘要

A digital control device and method are provided for controlling functions such as volume and tuning for an electronic radio in response to a digital rotary switch. The apparatus includes a digital switch movable to a plurality of positions and which has a plurality of digital outputs to represent the positions. Control increments corresponding to an amount of rotation and rate of rotation of the switch are stored in a memory. The rotary switch output is periodically sampled to determine when switch movement occurs and to further determine the direction of switch rotation based on a sequence of the plurality of digital outputs. The rate of rotation of the rotary switch is then determined from counting changes in position of the switch over a sampling time A control increment is looked up in the memory that corresponds to the determined rate. The control increment is then used to change a digital output signal for controlling the electronic device. The digital output signal may control volume for an electronic radio or may include a tuner selector for selecting the tuning frequency of a radio. Accordingly, the present invention enables one to have variable control of radio functions in accordance with predetermined rates of rotation of a digital rotary switch.