IR/RF/Other

[Timmymna]

I've had a little project planned for a while which is basically a remote that I can use to control a few things round the room, just basic on/off n possible one or two other things.
I'm a little stuck on deciding how to make the connection. I was going to choose either infrared or radio, or anything anyone can recommend.
I think I have the basics for IR down but would like to know a little about RF as I know nothing at the minute.
Can anyone give me some links to learn about using radio?
Are there any chips that contain everything needed or with minimal extra components?

Thanks for any advise given

 

[DigiTan]

If you're interested in radio (maybe you'll want to transmit beyond line-of-sight now and then), you can get a UHF transmitter/receiver pair from the Reynolds Electronics online store. They run at a higher cost than infrared, but they come with ample documentation to make it easier to get your project off the ground. There are also similar 433MHz transmitter/receiver pairs availible through Digikey that come in much smaller SOIC packages--and they run at about the same price.

IR would be the cheaper alternative. One thing you could do if you want to use an existing TV remote, is make a receiver that can decode infrared signals. The protocol involved would depend on the make & model of your remote. RC5 and RECS80 seem to be the reigning formats, but like I said, it all depends on the brand. There are a few decoder chips that will translate these signals into parallel/series binary for you, and I'll post up a link to one if you're interested. You'd also need a passive IR filter/receiver like this one to block out the extraneous noise.

 

[Nigel Goodwin]

You'd also need a passive IR filter/receiver like this one to block out the extraneous noise.

Except it's not a passive device, it's a fairly complicated IC, incorporating an entire IR receiver with only three pins - power, ground, and demodulated data out.

They are commonly used in everything with IR remotes these days.

My PIC tutorials show how to use PIC's to perform IR remote control, using the Sony SIRCS system - I use a similar IR receiver IC.

 

[Timmymna]

Thanks for the info DigiTan. I think I'll stick to IR for this project and leave RF till another day

Thanks Nigel, I have been reading your tutorial on IR and it has come in very handy! I'll be sure to come your way if I have any problems

Which IR receiver IC did you use and where can you buy it?

 

[Nigel Goodwin]

Which IR receiver IC did you use and where can you buy it?

The one I used was obtained as a spare part for a Tatung TV, but you can simply get one from any scrap TV or VCR - they are all pretty similar. Make a note of the connections first though, some are different ways round.