Air Conditioner Remote Control

Status
Not open for further replies.


Hi Nigel,

Well then you might want to explain why when we turn the TV volume up the VCR, SetTopBox, DVR Player, Audio Amp/Receiver, all dont turn off, is it magic or what

Correct me if i am wrong, but it sounds like what you are saying is that the remotes we can presently get on the market NOW do not do both entertainment stuff AND air conditioners. That is, right now, today. But how about tomorrow? Will there be a remote able to do this, and why not? I for one do not see a good reason why they should not do both. "Device" codes allow us to choose what device we turn on and off, while the other buttons just control what happens to that device such as volume or channel.
Could it be that there are no device codes left for new stuff like AC units? I would think adding another digit to the device code would give us another set of 1000 or so.

What hyedenny seems to be suggesting is that it is very possible and actually would be easy to have a remote control that could do both types of devices, especially since the codes are similar in at least some units. I guess it could be that the codes for SOME AC units are so unique that it cant be done for those models very easily, but then again it's just pulses of light.
 
the ir tx/rx is simple and en/decodes mostly anything , as most use that 38khz range

from there the cpu is used to drop that data in to a buffer, a smart remote just drops the appropriate data in to the buffer to match the device
if the remote buffer size is matched proper to ac unit then all you need is to drop the right code in it
if not then you need remote with or capable of proper buffer size, then drop the right code in
.... but we don't know what that is anyway

My smart remote is able to pair to most tvs, it also has selection buttons to choose which device "i am talking to". on the remote i enter the manufacture code, and that code pulls up the actual data map, so this would not work with devices not pre defined, my remote also has jtag2 header which i think can upload maps, which might work.... if we had the right map.... by altering this map we can do anything from changing devices to changing each buttons functions (i have never done so, so not sure details of how far it can go, but research shows that is the purpose of jtag header)

sometimes a code for one TV button is the same or similar enough that it can impact another "function/brand" of tv, but these are just small glitches that seldom appear.... for example i have seen power buttons for 1 tv switch inputs on a completely different type tv.

but since you are going at a receiver that we dont know the code for , the simplest may be a transmitter device built from scratch so that you can program it with a hammer code..... which would take a while to process and test all the code sequences plausible one by one, at which time would need to be watched to see if/when device turns off * or should i say "when target function is hit" .... if we were REALLY committed to this...

.... if we can get the pulse sequence for the AC it would help a lot as we also need to think about pulse lengths and start bit lengths (assuming they arn't all the same...but im not too sure, as i'v never traced a ac remote)... this is all plausible, if not done yet, and would be simple if we had the ac remote and could trace signal we need to copy.
then the smart thing to do would be to build a remote with a rx sensor on it so you could push a record button and "copy" the IR feed in to it from remote you want to copy.
 
Nigel --
Ya, if one was stupid enough to use the same codes -- out of the THOUSANDS that are available -- that one is using for his TV.
And silly semantics aside, I'm sure there are plenty of people who have no problem using their TV remote for other ancillaries such as lights, amps, dvd players, etc. I'm one of 'em.
 
i think his point is that you wont find a tv remote with lightbulb/ac manufacture codes on it ....my remote however can pair to dvd players
 
MrAl said:
Hi Nigel,

Well then you might want to explain why when we turn the TV volume up the VCR, SetTopBox, DVR Player, Audio Amp/Receiver, all dont turn off, is it magic or what
Click to expand...

I already have, device codes - plus command codes, which I didn't mention (as it wasn't relevant).

Correct me if i am wrong, but it sounds like what you are saying is that the remotes we can presently get on the market NOW do not do both entertainment stuff AND air conditioners.
Click to expand...

No, I'm saying that a TV remote won't work an aircon unit, doesn't matter if it's now, 20 years ago, or 20 years in the future - it will only work a TV (or something badly designed, and incorrectly using TV remote codes).

There's no reason whatsoever that you couldn't make a remote that worked both - but then it wouldn't be a TV remote any more. As I also mentioned, it's 'unlikely' a Universal TV remote would work an aircon, as it presumably wouldn't have the required aircon device codes, but a Universal multifunction remote 'might', it really depends on what codes are used (and obviously what codes are included in the Universal remote).
 


Hello again,

Thanks for the explanation, but it sounds like now you are wading into the shallow waters of sematics. Because of that i am forced to partially agree, but with great reservations. That's because what many people call a "TV" remote really isnt JUST a TV remote, it does other things too like DVD, Audio player, etc., no end to that list. Of course a TV remote that only does TV's is by definition ONLY a TV remote, but i thought this discussion was clear enough that we took it to mean a remote that can at least do DVD players and such, that is, NON TV's as well as TV's. Also, we might say that a TV remote that is a remote to a combination TV/VCR or TV/DVD player controls the "TV" and therefore TV remotes may be said to control other things too because of the secondary devices built within the SAME cabinet as the TV itself. I wont push that point however because i think we can just move forward with the discussion if we define "TV" remote to be a universal remote, although devices called TV remotes often control other devices too. If you prefer though we can go on to call them universal or "one for all" (Trademark) or something like that. The main point is we want to talk about remotes that normally control the TV and say DVD player, and how they might one day, if not already, control the air conditioner. The main goal here is to have just ONE remote control that does all the devices, not two or three or four laying around all the time. Up till now i could use just one remote for everything, why stop there

I for one would not mind having a "combination remote control" and i may end up building one, depending on time. With other things going on i dont get to build everything i want to build these days.
 

Not semantics at all - just accuracy - if you buy a TV you get a 'TV remote' with it, and it works the TV. If you buy a DVD player you get a 'DVD remote' with it, that works the DVD.

So if you've been discussing something completely different all this time?, than that explains why you're confused.

I don't think I know anyone who calls a Universal remote a 'TV remote'?, it's such a silly idea.

As I've said all along, it's easy to make a remote to control multiple devices, but commercially would be viable to add aircon to the list of devices? - probably not.
 

Hello again,

Yeah, that's not entirely true though. Like i said, some "TVs" also have a DVD player built into the same cabinet. You only get one remote with it. If you dont want to call that a TV remote then dont, or do, it's up to the 'beholder'.
 

Again, accurately, it's not - it' a combined TV/DVD remote - and many TV, DVD, Sound System remotes also actually have a few keys to control other devices.

But this still has nothing to do with Universal (or One For All) remotes, which are an entirely different category - and nothing to do with the equipment manufacturers.

However, now you seem to be 'hinting' about what you're actually trying to do - why not program a microcontoller to receive some specific buttons from your Universal remote, and output the required codes for your aircon?.
 
MrAl said:
Hi,

Anyone do one of these yet (any model)?
The pulse patterns look a little different than with the TV remotes, but similar idea.
I also have to wonder if a TV remote would work with an air conditioner.
Click to expand...

Hello again,

As you can see, there was really two questions at the start of this thread.
From the other replies you can see that some others took TV remote to be a universal type remote also. I can see from this also that you may have taken "TV remote" to be just a TV remote, and that is understandable, so let me reword that:
"I also have to wonder if a Universal remote of some kind would work with an air conditioner as well as it normally does with a TV."

And also as you can see, i was asking if anyone actually did an air conditioner remote yet and note this is in the microcontroller section. That would save me a lot of time perhaps. If not, then i have to start from scratch. What it looks like so far is that there have not been many projects that do this yet on the web.

So my most important question is if anyone has done a remote for an AC unit yet. If so, that might save me lots of time.
I may not even worry about a universal remote just yet, just build one that does all my stuff, regardless what device it is. That's unless i could find one at a reasonable price that does everything. I dont really want to spend 100 bucks on this but maybe as high as 40 if it can do all things i have right now.
 
I wanted to do such a remote, until I found I could get universal ones for less than USD10 at the local thriftshop. And it worked too, very well, until I sold the house.
Where I live, you can buy replacement remotes for just about anything in your home, at the retail level. Seems that lost remotes became quite a lucrative business here.
 
I made my own IR remote and the code is here:
https://libstock.mikroe.com/project...mb18-mmb33-and-mmb-stm32-m4-also-fusion-pic32

The two air conditioners that I was able to control were these:

---------------------------------------------------------------------------------------------
Air Conditioner Remote NEC protocol 006F
format is bytes 1,2 address 006F, byte 3 code as below, byte 4 inverse of byte 3
02 temp +
04 temp -
05 timer
06 func
08 fan speed
09 power on/off
0a sleep

---------------------------------------------------------------------------------------------

Air Conditioner 7000BTU Remote NEC protocol 10EF
format is bytes 1,2 address 10ef, byte 3 code as below, byte 4 inverse of byte 3
04 - down
05 timer
09 fan speed
0a + up
1a on/off
1e mode

press timer then both temp buttons together for farenheit/Centigrade display
---------------------------------------------------------------------------------------------

... obviously I have no way of knowing what protocol your air conditioner requires
 

Hi,

Yeah i just today saw one on the web made for air conditioners. It's a universal, but i think only for air conditioners.

The protocol for my AC is the simplest i've seen so far in remotes. It's basically as follows:
Long sync high, sync low,
start pulse followed by device code 8 bits,
sync low,
start pulse followed by button command 8 bits

That's it, no inversion at all. So it just sending 8 bits for the device code, then 8 bits for the particular button command.
I dont think i have seen that format before this.
 
Why not post the timing trace here and somebody (maybe even me) will recognise the protocol?
 
Hello,

Well it is as follows:
19ms low, 8ms high, low 4ms (sync),
0.45ms high, 1.6ms low (looks like the start pulse)
Bits, either one of these two:
0.45ms high, 1.6ms low for what seems like a logical zero (0)
0.45ms high, 0.6ms low for what looks like a logical one (1)
There are 8 of the above bits.
Then another 4ms low (intermediate sync)
then the same format as above start and bits (9 more pulses)
although those 8 bits are the command for each button,
then another 19ms low but that is probably variable depending on the bit states in the command byte.

It sounds more complicated than it is. All it does is send out a 0.45ms pulse followed by either 0.6ms low or 1.6ms low depending on the state of the bit, but the first 8 bits sent are always the same which i assume is the device code.
The second 8 bits sent, total time, could vary because of the difference between 0.6 and 1.6ms, so i think the 19ms low sync might get shorter if there are more zeros in the byte code.

Here's a look at the code in the way it appears where 'H' is a high and '_' is a low:
Code: 
____________HHHHHHHH (sync, start of message)
____H__H__H__H_H__H_H__H__H__  (first group of message, looks like 000101000)
____H_H_H_H_H_H_H_H_H_ (second group of message, looks like 111111111 all 1's for one key)
The above then repeats over and over again starting with the sync:
____________HHHHHHHH (repeat, start of entirely new message with same bits)


For another key the bits in the second group may change for example:
____H_H__H_H_H_H_H_H_H_ which looks like 101111111
and that also makes that code time take longer.  I'll have to verify if the 19ms low sync shortens or not.

The long 'lows' are about 19ms, the shorter lows are about 4ms, and the next shorter lows are about 1.6ms, and the shortest lows are about 0.6ms. So we have lows as follows:
Code: 
_____________ about 19ms but probably varies depending on the length of the second group in time,
____ about 4ms
__ about 1.6ms
_ about 0.6ms

You can see how simple this scheme is as compared to other remote protocols. I have read however that some air conditioner protocols are MUCH more complicated where not even the same bytes are sent out repeatedly, but change during a single button transmission. Lucky this one is simpler.
 
Last edited:
Does not look like any protocol I have ever seen.

Unless somebody else can spot a known protocol, then I guess you will have to write your own code to handle it.

Note that IR 3-pin receiver modules usually distort the transmitted signal (and by different amounts depending on range). If memory serves, marks are elongated and spaces shortened a little. For example, your 0.45 high - 1.6 low may actually be transmitted as perhaps 0.5 high and 1.5 low - ie regular timing units (t= approx 0.5 mS) of 1t high, 3t low.

I think that is me out of ideas for now.... good luck

EDIT: Oh.... or else just use a universal remote with learning capability. Not that any remote is truly universal. What we don't know yet is the modulation frequency used by your Air Conditioner remote control. 36, 38 or 40kHz are all easily handled by most learning remotes. 56 kHz is handled by many remotes, but not all. Other frequencies might only be handled by the most expensive remote controls.

What I have noticed is that "learned" messages are often not transmitted as reliably as the original remote transmitted signal. I tend to write my own code to more accurately transmit an accurate message, but then I am lucky that I have a lot of resources, understanding and interest.

What I have never achieved is making a remote as nice as commercial remote controls. Battery life on home made remote is severely limited. Best result I ever achieved was by building a receiver/transmitter that recognised spare buttons on my TV remote and then re-transmitted a different bespoke message to a foreign device (in my case a TV with lost remote). Even this was not ideal, as there has to be a delay between receiving and re-transmitting. Repeat codes were not catered for (such as holding down vol+ to give smooth volume increase.
 
Last edited:

It doesn't matter - that's why IR (and radio) remote controls don't use strict timing like RS232 does, instead using things like SIRC's and RC5.
 
Nigel Goodwin said:
It doesn't matter - that's why IR (and radio) remote controls don't use strict timing like RS232 does, instead using things like SIRC's and RC5.
Click to expand...
Beg to differ.... a distorted signal learned and re-transmitted is never as good as the original signal, but presumably some learning remotes will perform better than others . It is luck of the draw (and quality of design) as to whether the receiver responds to the universal remote's message as reliably as the original remote's signal. In my experience, range appears to be reduced with some learned signals.

Also it seems to need several attempts sometimes to learn the signal properly. I just find that learning seems to be a little bit hit-and-miss sometimes (but admittedly, "good enough" most of the time)

All depends on the protocol used and the tolerances accepted in the receiving device - IMHO (and I am no expert)

At the very least; if a logic analyser shows my own transmitted signal to have near identical timing to the specified protocol timing, it is one less variable when diagnosing problems.

A valuable lesson that I learned a while back is that the timing of signals from a remote control with a cheap battery can be a good bit off from a remote control with a branded quality battery (only true of some remotes - not all). And of course a new battery should be used when learning, as the manual will probably state.
 
Last edited:

Sorry, but in my experience that's completely untrue - and a simple examination of the protocols used easily shows that range has nothing to do with minor timing variations. If you're getting reduced range, then you're most likely doing something wrong somewhere?.

I've reverse engineered many different remote's, over a number of decades (originally back before Windows was even released), and all types have worked perfectly with no regard to the original exact timing.

As far as timing goes, it's not 'so many mS or uS' anyway, it's so many carrier clock cycles - with the source of the modulation usually from a cheap ceramic resonator, usually 455KHz or similar.

Thinking back, the first one I did was the Sharp TV remote - and it's so long ago I don't have a clue now what the protocol was - I seem to recall it was their own system, which doesn't matter any more as Sharp no longer trade in the UK (and most of their recent sets have been Vestel anyway, which use Philips RC5).


If there's problems with the battery, then it's most likely because it's low voltage, OR (a common fault in remote's) the reservoir capacitor is O/C - it's quite a 'good' fault, new batteries only last a couple of weeks, then you have to replace them. However, once you've replaced the faulty capacitor the old 'non-working' batteries are perfectly fine again.
 
I will bow to your wider experience....

Getting a little off-topic anyway, but always nice to learn new things.

Back on topic - I wonder what the OPs Air Conditioner IR Remote Carrier frequency is?
 
Status
Not open for further replies.

Similar threads

  • Question
Remote Control By Location Part 2--CONTROL SECTION
Replies
3
Views
3K
camerart
T
  • Question
Closed-loop stepper motor control problem
Replies
1
Views
606
rjenkinsgb
P
Which MCU for translating usb-midi to control LED lighting?
2
Replies
28
Views
9K
be80be
  • Question
MAX7219: 7-segment and 8-digit display control (Oshonsoft).
Replies
0
Views
470
DogFlu66
J
  • Question
How to find out RAM usage in Embedded Electronic Control Unit (ECU) ?
Replies
8
Views
3K
Nigel Goodwin
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…