anyone know at what frequency the IR modules work - looking at the manuals just now, it isn't said - could they handle 433MHz, for example ?
IR frequency ...
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we're looking to communicate between two distinct AV systems & the BM system (Idratek) ...
to set scenes & limit interruptions - when watching TV & movies, and listening to music & radio ...
the obvious & most convenient way is via RS232, which both & many other AV systems use ...
but Idratek can't handle that ...
so the options are via volt-free relay contacts working into digital inputs ...
or via IR (which both our AV systems also have) ...
IR systems have various protocols & work at various frequencies ...
one of our two works with modern protocols but at 433MHz, which is rather higher than the norm (and hence the question) ...
and the other works with rather old-fashioned protocols at more usual frequencies ...
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433MHz is one of the license free radio transmission frequencies. Most remote control type IR is carried over 36-40KHz (though there are some odd bods at 56KHz and elsewhere). So if something has a label with 433MHz on it I'm pretty sure it'll be radio not IR. The problem generally is not so much intercepting the signal whether it be RS232, IR or RF - for which the electronics is relatively straightforward - but more a case of understanding how to decode the protocol carried on this.
Possibly the most reliable to intercept would be RS232 since it is hard wired. If its a known protocol then it may be technically possible via existing IDRATEK hardware such as the X10 gateway or older PCA modules with firmware bespoking. But it might be easier all round to connect to a spare RS232 port on the PC and write a small bit of software to receive and then interact with Cortex via the API.
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detail point, but maybe I should have said 455KHz ...
as per this :
"... the overwhelming majority of IR remotes operate in the 30-56KHz range, normally 38-40KHz, several brands such as a Bang & Olufsen, particular Kenwood equipment, and some lighting control systems, use a 455KHz frequency ... "
BTW - the daughter-board on our Mini-ITX provides 4x RS232 ports ...Last edited by chris_j_hunter; 8 October 2011, 11:44 PM.
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PS: might be useful, in this context :
Last edited by chris_j_hunter; 9 October 2011, 12:15 AM.
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Originally posted by chris_j_hunter View PostOK, then 455KHz - is that within the capability of Idratek IR modules ? !
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Alternatively Chris, if you can wait a couple of months I'm going to be writing a small app that communicates with a virtual Idratek device and the serial port and transfers data between the two. I'm using it for some RGB controllers but it wouldn't be too difficult to change the strings within it to have the functionality you need.
Am very busy atm though with both my house and work unfortunately.
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Geps - that would be brilliant, ace ...
we need to send ASCII strings to & fro at 1200 baud (full duplex, GND TX RX, one start & one stop bit, eight data bits, no parity) - in case of interest, details are here :
ftp://ftp.studer.ch/Public/Products/..._B203_Info.pdf
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Originally posted by chris_j_hunter View Postwe need to send ASCII strings to & fro at 1200 baud (full duplex, GND TX RX, one start & one stop bit, eight data bits, no parity)
You may find that the serial ports on your PC already have that option built in so you would only need the RS422 line drivers at the distant end.KAT5.tv - affordable high quality AV Distribution
http://www.kat5.tv
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RS422 - yep, might well have to do that, to increase the range, co-location being tricky to achieve in our case ...
'have a feeling Geps' prospective code will be the start of something big, because RS232 comm's are quite widely used, in AV devices & a host of others, and if it can be readily adapted from his application to mine, then ... magic !
being able to send & receive would be key ... plus maybe extensibility in the virtual Idratek device ...
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