How are remote control codes received and interpreted?
A3 Signal edges are used to measure the length of each signal period in order to interpret the received remote control signals. Since the data that is output from the infrared remote control preamplifier is negative-logic data, these signals are described below as negative-logic input signals. Leader code section Since there is a 9-ms ON period for the leader code, an edge-triggered interrupt function or a program-driven polling function is used to detect the falling edge (A) of the input signal, and then the period between the falling edge and the next rising edge is measured. At the same time, the timer’s capture function can also be used to detect the rising edge (B) of the input signal and measure the period between edges. As a countermeasure against operation errors, the periods that are measured in this way can be judged as to whether or not they are within the normal range as leader code signals, and they can also be used to determine whether or not reception is possible even wh
