[Emon]

I was thinking about building a remote control receiver for controlling music on my PC. The transmitter would be the universal AV remote that came with my Panasonic XR55...I figured I could use it's generic functions to act as next track, previous track, play/pause, stop and any other functions like random track or something.

Writing a foobar2000 extension which reads data from the serial port is no problem. What I need to do is figure out how this remote works and how to build a receiver. I figured a fun way to learn would be to just hook up an IR photoreceptor to my serial port and write a simple program to decode the bitstream. Probably more difficult than it sounds, but I figure all I'd need to do is recognize a few commands anyway.

I've been Googling but I can't seem to find something simple enough - are there any pages on the basics of how remotes work? Or rather, how the specific hardware and encoding processes work (since I know how they work in principle)? I've found articles on making complete DIY remotes with custom transmitters but I'm not sure how it would work using my generic AV remote. Any suggestions?

 

[DolbyR]

i dont have the link now on hand so jsust google for lirc/winlirc website, from there u can find the schematics for what i've just build

 

[ericj]

Quote:

Originally Posted by Emon I've been Googling but I can't seem to find something simple enough - are there any pages on the basics of how remotes work? Or rather, how the specific hardware and encoding processes work (since I know how they work in principle)? I've found articles on making complete DIY remotes with custom transmitters but I'm not sure how it would work using my generic AV remote. Any suggestions?

Easier and more rewarding than writing an extension to foobar2000 extension for a single remote control receiver would be to write a WinLirc extension.

As for the technology - the infrared LED emits pulses that are modulated at a given frequency, anywhere from 30khz to 56khz usually, and a receiver part will be tuned for a particular carrier frequency. The carrier frequency is critical for reliable reception, but in practice a 38khz receiver part can usually recognize anything but 56khz just fine.

Aside from that, it's a matter of recognizing and decoding the pulses.

There are a dozen or so protocols, usually involving a device preamble ("Hey you! The Sony model foo1234 DVD player!") and then a command code. google for the jp1 remote control project if you want to know about the protocols.

For it's part, WinLirc and most other ir receiver daemons don't bother with understanding the signal - they just recognize the differences between signals they have been trained to recognize.

 

[blip]

Good advice here already... Only thing I have to add is that you can add all sorts of functionality to a remote control project if you use a PIC. Its pretty easy to do either with a regular PIC (if you know assembly) or a Basic STAMP/PICAXE (if you'd prefer to program in a BASIC like language).

If you're interested in either approach I've got some links stored away someplace that I could share. (Its all from the research I did for my perenially delayed Digital-Controled Tube Pre-Amp/Amp... I promise I'll build it someday.. really!

)

Though if all you are looking for is player control, WinLIRC (or plain LIRC if you're a Tuxedo-lover!) is more than sufficient.

 

[Emon]

Quote:

Originally Posted by ericj Easier and more rewarding than writing an extension to foobar2000 extension for a single remote control receiver would be to write a WinLirc extension.

Easier, yes, but how is it more rewarding? I'd rather not have another program running in the background if I don't have to. Not because of memory or CPU time, but because it's a less elegant solution, and programming a foobar2000 extension is something I've always wanted to do.

Thanks though, this is some really good advice...keep it coming!

 

[Emon]

I just found out that there's a WinLIRC component for foobar2000. Guess that leaves just building the receiver!

 

[ericj]

Keep in mind that the simple serial receiver they have plans for on the website is very timing-sensitive and may work poorly (or not at all)when the system is loaded or when the disk or network is very active.

If WinLirc supports the usbirboy, that's a receiver that shouldn't have that problem. Neither should the UIR aka irman, but that requires a PIC programmer that is a little more complex to build than the prommer used to program the motorola chip used by the irboy.

 

[Emon]

Quote:

Originally Posted by ericj Keep in mind that the simple serial receiver they have plans for on the website is very timing-sensitive and may work poorly (or not at all)when the system is loaded or when the disk or network is very active.

I scrap all electronics before throwing them away, I probably have parts to build a dozen of these.

Quote:

Originally Posted by ericj If WinLirc supports the usbirboy, that's a receiver that shouldn't have that problem. Neither should the UIR aka irman, but that requires a PIC programmer that is a little more complex to build than the prommer used to program the motorola chip used by the irboy.

Hmm, thanks, I'll look into it...

 

[ericj]

Build the simple serial receiver first - it'll take you 20 minutes and may work just fine for you.

I'm using one with my linux HTPC (1.2ghz mobile athlon) and lirc misses button presses for the first few seconds of any new mp3, for example, even though the mp3s are on an nfs server upstairs.

I'm planning on building the irboy, but I'm stalled with lack of time or pressing interest at about 90% construction of the prommer for the batwing mcu.

WinLirc is a slightly different beast, and you're probably using a faster machine. The simple serial dingus is only a little annoying on my box, may be not annoying at all for you.

If you have trouble with it, the resistor values are not set in stone and you may need to fiddle with them a bit to get it to work properly, just because serial port voltages vary from box to box.

 

[Garbz]

Just adding my $0.02 since I too planned something like this, except the opposite way around. Using the computer as a remote.

You can build an IRDA transiver, or something in the serial port. I believe the Serial port is much easier to program to but suffers from the problem that you can't get it to operate at 40khz which severaly effects the range of the remote.

I abandoned my idea AFTER building an IRDA device, but the IRDA device did work. There was just no software for it that I could find. LIRC etc all used Serial ports.

 

[Vynce]

Here's an excellent site that has lots of info on the different IR protocols. It also has assembly source code for PIC microcontrollers to decode most of the protocols.

http://www.xs4all.nl/~sbp/projects/i.../ircontrol.htm

 

[mbhauzer]

I'm noticing now that a number of tablets are including universal remote applications.  More justification for considering a tablet...

 

[bcg27]

 

[akgfan]

Haha.

 
But in case someone is searching forum, I bought usb receiver with remote control from eBay for just 1€ with free postage from Hong Kong. Cheap and effective. I use it 24/7. No need for building something.

 

[ROBSCIX]

Quote:

Haha.

 
But in case someone is searching forum, I bought usb receiver with remote control from eBay for just 1€ with free postage from Hong Kong. Cheap and effective. I use it 24/7. No need for building something.

You beat me to it, if you love to prototype go ahead but IR gear for PC is so cheap these days that you can save yourself alot of time and energy and just pick one up.