OP Code Reconfiguration of Keyboard Operations
Original Publication Date: 1980-Dec-01
Included in the Prior Art Database: 2005-Feb-14
Fig. 1 illustrates a generalized schematic diagram of a microprocessor-controlled keyboard. The microprocessor 1 provides a series of outputs on its ports to provide drive pulses to a matrix of capacitive keys 2 which are sensed as depressed or released by a sense amplifier 3, which is gated and has sensitivity levels selected by outputs from other ports of the microprocessor and which provides feedback to the microprocessor whenever a key is detected as depressed.