Universal IR remote controller

In these days of inexpensive PIC's and small non-volitile ram availability, you are lucky. The parts and the expertise to do the job is easily and cheaply attainable.

You need a PIC, a small non volitile ram chip and an inexpensive (short range) IR transceiver. With proper programming, this is a somewhat basic project. You might find that someone has done it already and/or has written the code that you can tweak to make it happen in your own case.

Check out the piclist mailing list at mit.edu. The mailing list is very active and the group has a large searchable archive of messages and many mb of searchable projects on the server.

Regards,

Mebart

You don't. Build an IR detector, and sampling system, that can read the IR data, at a significant multiple of the highest expected signal rate. Have a button to trigger 'learn', and have the system start recording when it sees IR activity. Store the sequence for a period of time. Then to simulate that command just replay the data pattern to an IR driver. So long as the period stored is longer than the expected maximum signal length, and the sample rate is high enough, you can simulate any remote. You don't store the 'signal codes', but record the IR pattern being produced.

Best Wishes

Hi All, I need to design an universal IR remote controller for my university project. It should work with most of the devices available on market and learn the codes from the original remotes. I did pretty much research on the Web but didn't find all I need. I wonder especially how the device will be able to store the signal codes, if coding differ depending on producer? Any ideas? Maybe someone's done a similar project and will be willing to share his knowledge? I'm pretty desperate since I have to finish the project for Monday.

Thanks in advance, Thomas W.

I think you have left it a bit late so Rip the chip out of a 1 for all remote, put it in a die cast box.

martin

"Wales is a big welsh-shaped rain collection device"

Realistically, a processor will be cheaper and simpler than using counters. Timing the 'on' pulses using a tone detector, is a pretty economical way to store the data, but does not cope with dealing with two or more different clock rates (some rare systems use 44kHz signalling rather than 38kHz). The commercial units using the sampling approach, just buffer the output of the photodiode, and use a delta ADC, to just return a bit stream reflecting whether the signal has increased/decreased from the last sample. Look at the codes for Bang and Olufsen remotes, if you want to add some headaches!...

Best Wishes

LOL!

Thanks! Rich

I worked at a place that made one of the first ones of these things - "Universal Electronics", I think it was. They had a huge pile of all sorts of remotes that people had sent them from around the world, and there was one guy whose job, essentially, was to sit there and capture codes from the various remotes. Full-time. ;-)

Cheers! Rich

If you really have to finish by Monday (that is, with a working remote) you are totally screwed. Take today to contact your professor and/or file paperwork for an incomplete, if possible. Then go see Revenge of the Sith, or whatever, and have a good time.

Or go study for your other classes, if needed.

This may sound harsh, but I am honestly trying to help you. ;-)

If all you have to submit is a design sketch or plan, then you might have a chance, and in that case carry on.

--Mac

Show a circuit with an IR receiver module going into a micro controller, show the micro controller driving an IR LED. Show a matrix of buttons going to the micro controller.

Tell your professor "Its all done except for the software".

--
Luhan Monat: luhanis(at)yahoo(dot)com
http://members.cox.net/berniekm
"Any sufficiently advanced magick is
indistinguishable from technology."

U¿ytkownik "Roger Hamlett" napisa³ w wiadomo¶ci news:LwFle.314$ snipped-for-privacy@newsfe6-win.ntli.net...

Thanks, that seems to be a very good idea. However I'm still wondering how do you imagine recording the pattern... I imagine it that way: The IR signal for remotes is usually sent with freq.

38kHz, and different codes have different periods of the low/high levels, thus I think after detecting a signal I should check it every 26us and increment a counter each time. When the signal inverts, I store the value of counter, null the counter and repeat the procedure until reaching the longer silence (like 20 ms). I calculated that to store all the possible codes (that I know) it will be necessary to have 512 bits of memory per each code/button. (Maximum of 32 signal inverts times 16 bits for the counter value) Is the above algorithm reasonable or can you think of any more effective ones?

Thanks a lot

Go find the first issues of Circuit Cellar Ink magazine, and the Byte magazines for the previous few months. (1987-1988?).

There was a project for a Universal Remote in the last few "Circuit Cellar" columns by Steve Ciarcia in Byte, and then an article, by Ed Nisley, describing the 8051 firmware design in a followup article in one of the first "Circuit Cellar Ink" magazine.

Hint: They make IR receiver modules with operating frequencies from

20 kHz to 95 kHz, so it may be more complicated than you think.

Mark Zenier snipped-for-privacy@eskimo.com Washington State resident

I confess I started reading this thread because of our own need for a universal remote control. We have (so far) purchased 3 'all in one' remotes to replace the aging units that came with the tv and vcr. Each one works fine...except that some functions are missing and there are flaws in each design. They all change channels, do basic recording etc, but try to set up a timed record event and there is no key to get into the vcr's set up. So, they are almost useless, for lack of 1 or 2 features that seem to be 'left out'.

I had wondered if they still made a remote that would read codes from the existing stock remote unit. I know they did this in the early days, but lately there was no need because non-volitile ram and EEPROM's could hold data for hundreds of different home entertainment devices.

Lately, there are new models coming out and the manufacturers can't keep up...........so, there seems to be a resurgence in the manufacture of 'learning' remotes.

I looked on ebay and there are many models that advertise that they 'learn' the code from the actual remote control to be cloned. A few sport backlit screens and USB connectors so they can be updated over the internet! I checked out a few of these in detail, and found that they all rely on the basic codes stored in eprom and you have to select what code you need for your particular device. When you run into a function that you can't use for whatever reason, you have extra buttons that can be customized (based on the output of the original remote).

I was not clear whether you could roll your own completely from scratch, or whether you had to start from the basic codes stored in the remotes eeprom.

But, clearly....this is the wave of the future. We intend to purchase one of these units soon.

While this can't help the original ops question regarding how to design one....perhaps he could purchase one and dissect it to get a starting place and go forward from there with his own design.

Regards,

M

I bought an RCA RCU807 unit from overstock.com. This unit has a learn mode that copies command from an existing remote and cost $25. Hope that helps. The high end product is the sunwave unit. It has not only learn and macro (combined commands for multiple devices) but is PC programmable. Check it out at

-=Don=-

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