[SOLVED] Microcontroller and RC5 protocol

[Jayagopal Kannan]

I am in an idea of interfacing at89s52 or atmega16 with a tsop1736 and decode the remote control signals using RC5 protocol.

The problem is , consider the case in which a particular button is kept pressed for , say 5 seconds ; then will there be any kind of time interval between the two data frames ? i know that each frame has 14 bits and all those stuff but will there be any time interval to distinguish two different frames. I wish to write a program with interrupt . so when there is no space between two frames then there comes a obstacle as to how to trigger the ISR exactly at the beginning of the particular frame or start bits.

 

[hexreader]

RC5 protocol is explained well here:

https://www.sbprojects.com/knowledge/ir/rc5.php

Note the statement: "As long as a key remains down the message will be repeated every 114ms." So with message length of 25ms, there will be about 90ms gap (quiet time) between messages

Note also that there is a toggle bit to distinguish between key held down and different key pressed.

 

[Jayagopal Kannan]

Thanks a lot , that link quite cleared the fog i was in , and your statement " there will be about 90ms gap (quiet time) between messages " helped a lot . Thanks a ton :wink: