# Universal remote control schematic diagram

#### yong

Joined Feb 23, 2008
27
Anybody has the schematic diagram of a universal remote control that can operate most of the home theater system??

#### hgmjr

Joined Jan 28, 2005
9,029
Greetings Yong,

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#### HarveyH42

Joined Jul 22, 2007
426
Anybody has the schematic diagram of a universal remote control that can operate most of the home theater system??
Universal Remotes are cheap $5-$20, doubt anyone has gone to the trouble of building their own, as it would cost more and likely look like crap.

Circuit-wise, just a microcontroller, IR LED, and a bunch of push buttons. Maybe a handful of resistors, capacitors, a transistor or two, crystal/resonator... The firmware is the hard part, since you need the codes for every function, of every piece of equipment in your home entertainment system. Not to mention, future additions or replacements.

It's really better to just buy one in this case, you won't save any money, it won't be anywhere near as functional, and won't look like something patched together after the dog chewed on it while you were at work. Unless you have a lot of free time on your hands, and nothing better to do...

#### mrmeval

Joined Jun 30, 2006
833
You can take an existing remote and wire the buttons to another microcontroller. If you take the time to trace out the connections you can lose a good half of the board with a saw so that it will fit in an enclosure.

#### spar59

Joined Aug 4, 2007
57
I can see that if the home theatre system is fairly complex then the cheap universal remotes wouldn't handle it for 2 reasons - it must be a learning remote since most universal remotes are only programmed to mimic dvd players, vcrs & tvs and it must be able to cope with a huge number of functions which may have unusual names.

What is needed is a touch-screen remote where the button graphics can be changed as necessary and is able to store multiple screen layouts - not cheap but they are available and can even be programmed with macros - e.g. "All Off" button issues "Off" commands to every device in turn or can turn on the appropriate bits of kit and make appropriate selections e.g. "Music 1" issues Digital Tv box on/select music channel, TV on/tv sound muted/tv to AV1 input, Surround Amp on/audio source = DTV/sound processing to disco/volume 50%.

Phillips / Marantz led the way with the PRONTO but there are quite a few models these days - try specialist HI-FI dealers, be prepared to spend £100 - £200 though (in the States you would probably get one for the same figure in dollars), to be honest it is beyond the scope of all but the most experienced home-build enthusiast to put together anything like one of these.

Steve.

#### HarveyH42

Joined Jul 22, 2007
426
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=2155680&sku=L23-7112

$80 for 15 devices, but the detail that caught my attention... You hook it up to your computer to set it up and teach it the codes. Still think buying one, is the more sane solution, considering the design work for the case and buttons. Also betting there are several software solutions availiable for PDAs and such. Really can't imagine too many people taking on a project like this from hardware on up, but then again I barely watch broadcast TV, but it's on a 55 inch screen... Thread Starter #### yong Joined Feb 23, 2008 27 Hi and thanks to all Bros/Sis who replied to my thread. First of all, the reason why i need to locate the schematic of a universal remote control was to understand in detail the circuitry on how the remote control works.The reason being I am currently trying to design some hardware which will automatically pause the hi-fi/dvd or mute the tv upon the arrival of an incoming call.I had already design the front part which consistutes of a phone detector circuit which will trigger the RF TX upon arrival of the telephone ringing, an RF RX will be placed in another room which the theather system is lcoated.Upon recieving the signal,"something needs to happen" to trigger the mute or pause. Anybody can give me some idea how i could design the last part.My initial idea was to integrate a universal remote control to the RF RX but i do not know how i can do it.Please englighten. Thread Starter #### yong Joined Feb 23, 2008 27 Hi and thanks to all Bros/Sis who replied to my thread. First of all, the reason why i need to locate the schematic of a universal remote control was to understand in detail the circuitry on how the remote control works.The reason being I am currently trying to design some hardware which will automatically pause the hi-fi/dvd or mute the tv upon the arrival of an incoming call.I had already design the front part which consistutes of a phone detector circuit which will trigger the RF TX upon arrival of the telephone ringing, an RF RX will be placed in another room which the theather system is lcoated.Upon recieving the signal,"something needs to happen" to trigger the mute or pause. Anybody can give me some idea how i could design the last part.My initial idea was to integrate a universal remote control to the RF RX but i do not know how i can do it.Please englighten. One idea was to design a PIC microcontroller to program the remote control codes.But my programming sucks, is there any other way which i can make use of hardware only to achieve my objective? #### HarveyH42 Joined Jul 22, 2007 426 One idea was to design a PIC microcontroller to program the remote control codes.But my programming sucks, is there any other way which i can make use of hardware only to achieve my objective? I wouldn't say it can't be done in hardware only, but not very sane or reasonable. Sort of like building a calculator without silicon. Remotes send codes, which is what computers are built for, so use one. There is a web project (I built one) called TV-B-Gone. You can download all the project files and code, buy a kit, or ready built. Mentioning this, because you could modify the codes to pause or whatever. If the goal was to just kill the noise when the phone rings, this would shut the TV off, as is. But it's pretty close to what you want, most of the tough work is done. You just need to find the codes, or figure a way to make it learn from your remotes... Thread Starter #### yong Joined Feb 23, 2008 27 I wouldn't say it can't be done in hardware only, but not very sane or reasonable. Sort of like building a calculator without silicon. Remotes send codes, which is what computers are built for, so use one. There is a web project (I built one) called TV-B-Gone. You can download all the project files and code, buy a kit, or ready built. Mentioning this, because you could modify the codes to pause or whatever. If the goal was to just kill the noise when the phone rings, this would shut the TV off, as is. But it's pretty close to what you want, most of the tough work is done. You just need to find the codes, or figure a way to make it learn from your remotes... Hi, may i know where can i download the codes? #### hgmjr Joined Jan 28, 2005 9,029 Take a look here. hgmjr Thread Starter #### yong Joined Feb 23, 2008 27 I wouldn't say it can't be done in hardware only, but not very sane or reasonable. Sort of like building a calculator without silicon. Remotes send codes, which is what computers are built for, so use one. There is a web project (I built one) called TV-B-Gone. You can download all the project files and code, buy a kit, or ready built. Mentioning this, because you could modify the codes to pause or whatever. If the goal was to just kill the noise when the phone rings, this would shut the TV off, as is. But it's pretty close to what you want, most of the tough work is done. You just need to find the codes, or figure a way to make it learn from your remotes... Do you think if its possible to modify from existing universal remote control?the hardware? #### HarveyH42 Joined Jul 22, 2007 426 Have you ever popped open a remote? Find a broken one, or get a cheap$1.00 special from some surplus site, as some are really tough to pry open. The keypad is a conductive rubber membrane and matrix of traces on a PCB. On the PCB, there is a large, black, blob. This is the microcontroller, and there is no markings to indicate which one.

One of the TV-B-gone project pages had references to codes, but might have been just power codes. Try this one, maybe the forums there will get you some help.