Digital control system and a method of transmitting control data in such a system

摘要

TV low cost remote control system using a microprocessor decoder. Control data is transmitted in digitally encoded form and comprises blocks of eight bits of data separated by gaps in transmission of equivalent length. Each data block consists of a start bit followed by seven bits of data for channel identification. Data is presented to the microprocessor on one input line which it samples regularly as a part of its main keyboard scan routine and in response to a start bit checks the data bits and gaps to determine presence of a valid command. The remote control information is decoded directly by the microprocessor. Using seven identification bits, a channel capacity of 128 channels is possible.