ACCESSORY DETECTION BY OSCILLATION
Original Publication Date: 1996-Aug-01
Included in the Prior Art Database: 2002-Apr-23
Subscriber radios have a need to scan for multi- ple different accessories at their accessory connec- tor. Traditionally, options are detected using a binary coding scheme shown below in Figure 1. Each acces- sory is assigned a different combination of Rl and R2 values so that a unique binary code is presented Subscriber Radio to the microcomputer. This requires a large number of dedicated I/O pins and microprocessor lines for the simple process of determining which accessory is connected. Such dedication of resources is waste- ful and expensive for subscriber radio products.