Measuring infrared pulses

Willie Erasmus · Guest

Hi there

I've seen the posting on "Measuring a pulse with 1us resolution", but Acetoel only want to measure one single pulse. I want to measure the successive pulses from the infrared reciever to decode the signal. Can somebody give me some direction how to do that. My infrared remote control transmits a signal with different pulse width indicating '0' or '1'. (Tested on digital scope)

Thanks
Willie
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This message was ported from CCS's old forum
Original Post ID: 13071

Tomi · Guest

Maybe you don't need to measure the pulse width. Just wait for a rising edge then wait [("0" pulse width + "1" pulse width)/2] time then check the input line. If it is (already) "0" then the bit is 0. If it is (still) "1" then the bit is 1.

:=Hi there
:=
:=I've seen the posting on "Measuring a pulse with 1us resolution", but Acetoel only want to measure one single pulse. I want to measure the successive pulses from the infrared reciever to decode the signal. Can somebody give me some direction how to do that. My infrared remote control transmits a signal with different pulse width indicating '0' or '1'. (Tested on digital scope)
:=
:=Thanks
:=Willie
___________________________
This message was ported from CCS's old forum
Original Post ID: 13072

Willie Erasmus · Guest

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___________________________
This message was ported from CCS's old forum
Original Post ID: 13075

Sherpa Doug · Guest

Perhapse I can rephrase what Tomi said:
Let x be the length of a short pulse ("0").
Let y be the length of a long pulse ("1").
Assume pulses are active high.
1) Wait for the start of a pulse.
2) Wait (x+y)/2. By now a short pulse will have ended, but a long pulse will not have ended.
3) Test the input. If it is low it must have been a short pulse. If it is still high it must have been a long pulse.
4) Wait for the start of the next pulse....

SherpaDoug

:=Maybe you don't need to measure the pulse width. Just wait for a rising edge then wait [("0" pulse width + "1" pulse width)/2] time then check the input line. If it is (already) "0" then the bit is 0. If it is (still) "1" then the bit is 1.
:=
:=
:=:=Hi there
:=:=
:=:=I've seen the posting on "Measuring a pulse with 1us resolution", but Acetoel only want to measure one single pulse. I want to measure the successive pulses from the infrared reciever to decode the signal. Can somebody give me some direction how to do that. My infrared remote control transmits a signal with different pulse width indicating '0' or '1'. (Tested on digital scope)
:=:=
:=:=Thanks
:=:=Willie
___________________________
This message was ported from CCS's old forum
Original Post ID: 13085