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Pulse sequences from infrared camera remote

I have now got a picaxe chip to turn on and off a camera infrared remote and so activate the shutter of the Canon G2 at regular intervals. (Thanks David, thanks Phil) Simple enough, if a little messy and tedious. But I am getting a little more ambitious. It is obvious that I can discard the I.R. remote control and drive an I.R. LED directly from the picaxe, if I could find out what is the sequence of pulses that the camera is expecting. The picaxe has an inbuilt set of I.R. codes, all of which I have tried, to no avail. The picaxe can also send single pulses, and I believe this is the way to go. Find out what is required, write some little loops, and fit the 8-pin picaxe, a couple of resistors and an infrared led and a couple of batteries into a Dick Smith switched battery case. It all comes back to knowing what pulses to send. Canon is hopeless. Their websites are hopeless, and if you finally get through to a human being, they are hopeless. I guess they wouldn't disclose the information anyway. It might cost them a $19.95 sale or two. But there has to be a way to find out what the hand-held I.R. device is sending. Any suggestions? I have a few computers available, and an old CRO. I wonder if there is some way to remove the IR LED in the hand-held, and send the output to a sound card and look at the input some way. Someone out there has the answer, and it might well be one of you guys. I hope so.

Reply to
L.A.T.
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The easiest way would probably be to build a serial port IR reciever, like this:

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That would allow you to capture and decode the data.

In fact the LIRC software package support some Canon remotes already:

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The G-1 remote is here:

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Dave.

Reply to
David L. Jones

LIRC (which is Free software designed to capture IR and play codes) and audacity (which among other things records from the sound-card input and displays wave-forms)

Most IR remotes work by sending bursts of 38Khz (-ish) square-waves to the IR led, 38 Khz is going to be hard to pick up on your average sound-card so probably LIRC (or winLIRC) is your best bet.

Bye. Jasen

Reply to
Jasen Betts

snip

It is getting interesting. I am sure I can now use the picaxe to send any string of pulses of any duration and any spacing. I know that at least I am sending something because the display at the back of the Canon G2 shows the flashing from the IR remote as a white flash, and shows that the flash from my device is at least as bright and of a similar duration. I have Googled for a couple of hours, looking at lirc and winlirc. It is evident that the fragments that are posted (including the one in the sourceforge WLDC100 mentioned above) are parts of some greater piece of software that I can't decipher. I have tried outputting the 16-bit strings quoted with no result. For want of a better protocol, I am using the bit-length, bit-size, and inter-bit silence used by the Sony protocol. I imagine I need some preamble and postamble to those 16-bit strings but I can't find out what, if any, they are. It is a little un-nerving to me that those posted fragments don't seem to have much in common. I am grateful for the help I have had so far, and hope for some more guidance.

Reply to
L.A.T.

I recall seeing an artical in SC that described a chip that could be used to receive and record IR pulses and could then, on command, resend the sequence.

It is/was produced by a New Zealand company. Sorry I don't have the issue details but perhaps it will ring a bell for someone else in the group.

I was interested in using it to control a VCR from an ad blocking program running on a PC but I never got the software running reliably enough.

HTH

Dave G.

Reply to
Dave Goldfinch

Found it !

It was not quite as I remembered - The article actually described a device turning a VCR into a security recorder: "Wachit" in September

2006 issue of SC. Thi used a chip suplied by Farco Technologies in NZ.

Browsing their website Farco.co.nz/products.html, shows their "Remote Control Learner IC" - IRL-10 which seems to fit the bill for your application. Cost is quoted as US$10.27. You can also download the Technical Reference from the site.

HTH

Dave G.

Reply to
Dave Goldfinch

Thanks. I'll look it up tonight.

Reply to
L.A.T.

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