Controlling A/C remotely (what to use?)

[stj]

Re: Controlling A/C remotely (what to use?)

well it's in "C" so using a microcontroller wouldnt be a problem.

[redwire]

Re: Controlling A/C remotely (what to use?)

The Arduino libraries have over 1,500 entries.

I found a Midea Air Conditioner library, it uses the Arduino and an IR LED to generate commands.

Example use explained, C code

I would try it, see if it works with your air conditioner, as step #1.
I don't know the Midea brand, but it could be a common control board.

[Dannyx]

Re: Controlling A/C remotely (what to use?)

Another promising article here. In parallel, I also began looking at OpenHAB. It's what my buddy uses for his lights and blinds at home and he recommended it here too.

[Dannyx]

Re: Controlling A/C remotely (what to use?)

Hello once again chaps. Hopefully you're still subbed to this thread. Wanting to get started with this project, with a little help from my buddy, I began thinking about how I'd go about programming an ESP8266 to do the trick. I'm aware there are versions which have the programmer built in, but they're not currently on stock on banggood, plus you know me, I like complicating things
I want to use to my CH341 programmer to do the job - I know it works because I've programmed my arduino Pro Mini with it, so I imagine I'd work just as well with the ESP, especially since the very same CH341 is used on the pre-assambled boards, alongside the ESP, so I have the two, just as two separate entities.

Not many tutorials on this though....TX goes to RX and vice versa I imagine, however there's a little difficulty: ESPs run at 3.3v, which is no doubt correct - I'll power it from the 3.3v header of the CH341 programmer (looks like this BTW), but what about TX and RX ? Don't they need a level shifter or a setting to ensure the CH341 programs at 3.3v ? If I try it directly, I imagine that can't be good - the ESP won't like it and could blow a seal

[stj]

Re: Controlling A/C remotely (what to use?)

you connect tx,rx and gnd.
and on the esp you ground an input called BOOT0 to start in the serial loader instead of the application memory if it's like other arm-core chips.

[Dannyx]

Re: Controlling A/C remotely (what to use?)

Ok, but what about voltage ? Actually, I had a look at a serial programmer that looks just like the one I got (I'm at home, so I don't have it on hand to look at it) and it would seem the CH341 is powered by a 3.3v regulator on the back, meaning the TX and RX levels would be correct as well, since they can't exceed that. The Arduino Pro mini I'm currently using it with runs natively at 5v, so I didn't give it second thought, so that's what made me think the CH341 operates at 5v levels and requires some sort of hack/mod to run with the ESP, but it turns out a 3.3v signal can program a 5v arduino.

[stj]

Re: Controlling A/C remotely (what to use?)

ch341 can output either - it's a very good chip, but most 3.3v mcu's have 5v compatable inputs anyway.

[Curious.George]

Re: Controlling A/C remotely (what to use?)

Problem being, that likely the desire is to keep the AC turned off when there are no occupants. When an AC is being used, this is most likely be used during the summer, and to keep the AC off, that sensing element needs to be kept cool.

No, you just set the thermostat's setpoint higher than normal (to a temperature that keeps it "off" when you want it to be off).

But, you're stuck having to move the temperature controller into the "external device" -- which is actually a win because now you can not only control ON/OFF but the actual temperature setpoint in effect! (your interface to the actual ACbrrr is a "thermal one" and not electrical... no worries about galvanic isolation, interface compatibility, voltages, etc.)

[Curious.George]

Re: Controlling A/C remotely (what to use?)

Nope - all of that is too complicated. The A/C is not permanently installed as you can see and it's not a HVAC system employing a thermostat, so the only method here is the remote.

You might not be able to recognize the thermostat as such but you can bet it has a thermostat in it, somewhere. After all, it's purpose is to react to high ambient temperatures (where "high" is defined by the TEMPERATURE that you have specified).

I.e., it's a closed loop system so there is a temperature sensor, somewhere, and, by definition, a "thermostat" (that performs the control function).

Using a remote is fraught with potential problems because remotes aren't designed with feedback in mind; it's up to the user to decide if the controlled device has "seen" the command and responded as the user expected.

[Dannyx]

Re: Controlling A/C remotely (what to use?)

Yes, it obviously has a thermostat, but people were most likely discussing a wall-mounted or external thermostat, so I just wanted to clear that up. True - no feedback for remotes. It has to rely strictly on ensuring the device reacts. Actually with a lot of effort I imagine there COULD exist a feedback system: by tapping into the A/C's MCU or whatever, it can report back and tell the microcontroller (IR emulator) whether or not it's responded - WAAAY beyond what we want to/can achieve here. The hardest part is going to be snooping the remote codes...implementing OpenHAB and stuff like that will be somewhat more enjoyable.

[Curious.George]

Re: Controlling A/C remotely (what to use?)

\Actually with a lot of effort I imagine there COULD exist a feedback system: by tapping into the A/C's MCU or whatever, it can report back and tell the microcontroller (IR emulator) whether or not it's responded - WAAAY beyond what we want to/can achieve here.

No, unless you know how the MCU is coded, you have no way of knowing if:

• it didn't see the command
• it saw the command and is acting on it ("real soon, now")
• it saw the command but has deferred action (cycle limits on compressor)

That's the problem with "event interfaces" (sending an Ir code is an event) vs. "static interfaces" (holding something warm under the sensor until YOU see the desired room temperature). It is fairly common for event-driven systems to "miss events".