TV Universal Remote?
JoeA
Posts: 33
Has anyone tried using Parallax microcontrollers to implement a universal TV/home theater remote control?· Is there any way to get the specs for the IR signals for these, or must one reverse-engineer the specific products's remotes?· (Which should also be doable with a microcontroller and suitable sensors, right?)
Joe A
Joe A
Comments
Are you sure you want to make another one?
If you still want to, I will help you with the SX processor.
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You will need to do some reverse engineering.
Read the Parallax Understanding Signals and IR Remote for the BOE-BOT paper. This will help you better undrstand the protocols involved.
http://www.parallax.com/dl/docs/prod/sic/Signals.pdf
http://www.parallax.com/dl/docs/prod/sic/WebIR-%20v1.1.pdf
IR Remote protocols links
http://www.lirc.org/
http://www.lirc.org/
http://www.vishay.com/docs/80071/dataform.pdf·The NEC protocol and its variants are·very popular.
Also check out Parallax Resorces, Customer Applications,·Home Applications, IR Repeater. I was successful at controlling a Magnovox TV and RCA Sat. Receiver. I am currently working on custom IR remote with BIG knobs and BIG buttons for an assited living facility.
http://www.parallax.com/html_pages/resources/custapps/app_irrepeater.asp
I used two stamps. One for the repeater receiver/transmitter·and one to measure the pulses to adjust the timing and get it correct. A poor mans scope.
Keep in mind that Basic Stamp and PBasic are not that fast. I used a 38KHz/40KHz modulator and ceramic resonator from Reynolds Electronics.
http://www.rentron.com/remote_control/TX-IR.htm
http://www.rentron.com/Files/TX-IR.pdf
I will follow up with additional IR protocols. Search this form for them
I hope this helps.
Stephen Wagner.
I missed this cut and past WWW link.
If you understand the IR protocols, the link above might have the specs you are looking for.
The specifications can be confusing. Post the remotes you are trying to reverse engineer.
Stephen Wagner.
http://www.celadon.com/infrared_protocol/infrared_protocols_samples.pdf
http://www.sbprojects.com/knowledge/ir/ir.htm
http://www.hw-server.com/docs/IrDA_standards_and_protocols.html
Good Luck.
Stephen Wagner
For instance....
I have been fooling with having the BasicStamp receive codes from unused function buttons on my main T.V. remote and convert them into toggles for other devices. That is easily done.
I have also considered having the BasicStamp convert received codes into what is acceptible on another device; then retransmit. In this way, I can have the T.V. remote turn on and off my air conditioner. I don't have to reach for another remote.
In order to sort things out, I have two universal 'programable' remote controls that will take on the format of 100s of manufactured T.V.s and V.C.R.s. But these are mimicing the transmission personality of only one at a time. Having one receiver for all codes seems a bit absurd and unsupported. It really is about getting as many functions out of the buttons in one device as possible. Trying to create a data base for all the personalities in an EEPROM is quite unneed and expands· greatly the·work effort.
Hacking into and decoding each empty button is quite doable, but a bit tedious. They vary in bit length and a start up sequence. The BasicStamp can capture and display the timing for each button in Debug. A Sound Card Oscilloscope can easily capture and display the whole timing sequence from the receiver/demodulator because it is quite slow [noparse][[/noparse]far below 20,000Hz].
So, the real trick is to focus on exactly what you want it to do rather than ask for complete universitility [noparse][[/noparse]too many permutations].
The beauty of the IR remote control is it is an already·completed User Interface. So I would find one with a lot of empty functions, program it to recognize most of my appliances, and then, use a BasicStamp as a converter/repeater for the devices it has not managed to reach. [noparse][[/noparse]see PDA comments below]
IrDA is a whole different can of worms. Firstly, it is data transmission in serial bytes at a much higher speed and generally over shorter distances [noparse][[/noparse]like inches]. Secondly, the data has a strict software transmission protocol in packets·that must be understood and followed. I suspect that this is not what you want and that it would waste your time. But it is already available in the PDA.
Alternatively....
You might consider buying a PDA with remote IR software included or IrDA interface built in. I had a SONY Clie that would reach many devices.
In fact, I suspect that you will find after-market software to install a universal remote on any PDA with IrDA·these days. And, you will also have IrDA transmission available to your cell phone, computer, or whatever. And then, you not only have an excellent·universal remote in one package, but a substantial handheld·computer. My current Palm PDA includes a 2 gigabyte SDcard. The only thing I lack is the WiFi to reach the net [noparse][[/noparse]it has BlueTooth], which I'll be sure to get in my next upgrade.
And, that PDA Remote can just as easily reach a BasicStamp for added functionality. You can even run your BOEbot to fetch the newspaper.· You will certain get more 'bandwidth' of IR remote control out of it.
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PLEASE CONSIDER the following:
Do you want a quickly operational black box solution or the knowledge included therein?······
Post Edited (Kramer) : 10/27/2007 6:06:37 AM GMT
This is·to say, recording and saving.
This is the way many universal remotes work. They do not need to store anything from factory, although usually they do it.
It sounds like the SXes would be better suited for doing the job of learning from one remote to another than a BasicStamp, in fact the SX-48 has built-in capture hardware. PBasic is just not as compact as SB/X or SASM.
But I suspect to simply capture and repeat a sequence can be a bit tricky to devise.
From my own observations on a scope, the transmited commands can at times be flawed. We don't notice that we merely press the button again when this happens, but it does occur often. Also, some commands are combinations of buttons - like two and three digit channels; while others are single button commands. The former commands generally transmit only once. And, some commands get repeated if the button is held down - like volume up/down functions. Finally, some buttons do not transmit at all, but change the character of the keyboard's transmission data to reach a different device [noparse][[/noparse]in other words, these buttons allow the numerical buttons and some functions to be shared by different devices].
Does one really need to build the hardware? I have my doubts. Some PDAs are quite reasonable in price.
There may be the possiblity of creating an original PDA program that would both allow you to learn and build a complete interface in software. Palm has its own version of C available for such tasks.
Each and every remote controlled device in your home could be provided a separate keyboard screen and each could have a distinct background color to ease recognition. And the IR receiver and transmiter are already in place. I just don't see any reason to build a chassis, power supply, and include a key board when there are already so many of these good user friendly devices available.
And the BasicStamp or the SX is always there to easily control anything that you want to DIY.
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PLEASE CONSIDER the following:
Do you want a quickly operational black box solution or the knowledge included therein?······
JoeA