Hi,
I was wondering if someone knew the carrier frequency and bit time ( the time in between repeats) of the microsoft media center remote. I already have it working via jp1. I am just experimenting with another IR receiver on the pc and need to knowwhat to sample at.
thanks
Help with Microsoft MCE IR protocol
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Re: Help with Microsoft MCE IR protocol
The carrier frequency is 36Khz.zinkpig wrote:the carrier frequency and bit time ( the time in between repeats)
I don't see how the "bit time" could be explained as "the time in between repeats", so I think you have a serious misunderstanding in there.
The level that repeats is what I call a "frame". The frame is about 37.3 milliseconds long and there is a gap of about 68.8 milliseconds between frames. So it repeats about every 106 milliseconds.
Within a "frame" there are 32 data bits and a variety of other structural information. Each data bit is .888 milliseconds, but it is phase encoded, so the correspondence between bits and IR bursts is not as simple as in other encodings (32 data bits could take anywhere from 16 to 32 IR bursts, in addition to structural IR bursts).
The first IR pulse is about 2.66 milliseconds. One of the others is about 1.33 milliseconds. All the rest are either .444 or .888 milliseconds. Each of the gaps within the frame are either .444 or .888 milliseconds.
Hey thanks for that info. Yeah I had it wrong. I am trying to use the MCE remote with the keyspan USB IR receiver. My main reason for doing so is because of the nice feel of MCE remote for sage TV. I am essentialy trying to use keyspan like girder. However, the keyspan mapping protocol allows only a carrier frequency and what they refer to as bit rate, for a JVC remote this is set as 520. which seems about right according to http://www.xs4all.nl/~sbp/knowledge/ir/jvc.htm
For the mce remote I set it as 373 and captured the data bits. The data i captured showed 32 bits for most keys(num 1-9), for some keys there were 33 bits(num 0). which is prob because of the phase encoding, The length of the frame would keep changing. However I can get repatable codes for each keypress so I could use those for events if I wanted. I doubt I ll use it though seems to klutzy. I ll look in to other remotes that have a nice feel. prob a sony remote as I have the protocol mapped in to keyspan.
For the mce remote I set it as 373 and captured the data bits. The data i captured showed 32 bits for most keys(num 1-9), for some keys there were 33 bits(num 0). which is prob because of the phase encoding, The length of the frame would keep changing. However I can get repatable codes for each keypress so I could use those for events if I wanted. I doubt I ll use it though seems to klutzy. I ll look in to other remotes that have a nice feel. prob a sony remote as I have the protocol mapped in to keyspan.