Cooler Controller needed

[CoolCooler]

Newbie here and not sure which forum to put this in so will start here. We have a window mount evaporative cooler with remote control for System on/off, Pump on/off and fan low/high. It works OK, but sometimes it gets too cold and needs to be turned off for an hour. But, the poorly design system needs the remote directly in front and a max of about 7-feet.

I tried using a plug in thermostat, but the system will not start when power is applied. Probably to prevent false-starts after a power outage. Well, I'll give them the benefit of the doubt, so the thermostat turns the cooler off at the low temp, but when it is time to turn back on, it reapplies power but the cooler will not start without a button press. To be fair, it does remember the last settings for Pump and Fan speed.

OK, getting a little long, but I am thinking of cutting into the lines to the fan and the pump and take control ignoring the remote system.

I saw Pete B's videos on Youtube and here I am. So, before reinventing the wheel, I thought I'd ask has it been done? I want to have inside and outside humidity and temp sensors as the cooler does not work at higher humidity levels and needs to be shut down.

I am a retired programmer and OK with building electronics but not so good at designing circuits. So, first question is, is there anything like this I can copy or extend?

If not, I am thinking an Arduino, two humidity/temp sensors, maybe a real time clock as I may later program it for Winter Summer etc and an 8-relay board. I like lots of relays for for additions.

Can anyone here please get me started with this project?

Thanks In advance.

[Moshe Livne]

For a different approach, must less intrusive, you can try http://forum.mysensors.org/topic/1662/air-conditioning-hvac-control-work-in-progress

[CoolCooler]

Thanks, I had already pulled (now sticky taped back together - {gasp}) the thing apart for doing that. But then after watching Pete B's videos, I thought I'd like to automate it with an Arduino so it would know if it is too humid outside, to be running.

Since my first post, I have thought about using the IR and getting the Arduino to send to an IR-Tx glued over the cooler IR-Rx. The current remote is pretty useless having to be so close and directly in front, so no big deal covering it up.

I need to record the output for each button press on the remote then have the Arduino replicate them.

Suggestions for where to get started with that?

Thanks

[Moshe Livne]

@CoolCooler as detailed in the post, the recording and playing of aircon is far from trivial. Actually, i don't think I have seen anyone making it reliably. Every keypress send the full new state, not only the modification. So, if you press temp down you actually send fan speed, new temp, vane, etc. The remote i used could work for you. I suggest you invest 3$ and find out... The remote is mysrnsored do the controller can adjust the settings based on other sensors.

[CoolCooler]

Thanks, and I admit I am new to Arduino but NOT to programming (40+ years). Unless it is a severe limitation of the available Operating System AND programming functions, I can't see how that would be necessary instead of sending individual commands.

I have ordered the parts and will see what's what. But, I will be really disappointed at the Arduino if that is the case. At worst I can throw the Arduino away and use a RaspPi as it has a full function OS and programming functionality.

[tbowmo]

There is a library out there somewhere that can control hvac directly via IR, without the need to learn IR codes from the remote (which can be a pain as stated earlier by others, since it's not just a simple keypress CMD that is sent)

[Moshe Livne]

@CoolCooler You have but a few years of experience on me I was also new to arduino until a year ago.
Anyways, a slightly more detailed explanation, gathered from many sources:
The HVAC codes are defined as states, probably for historical reasons. The HVAC will probably not recognize or respond to partial state. The only thing that is not a state is the off code. You can see this in action if you cover the remote, switch mode to, say heating, uncover it and press temp down. you will get the HVAC heating afterwards although the code was not sent
To add a bit more complexity to the equation, even if you have the right setup to reproduce the codes, every HVAC has different coding scheme and as "recording" IR actually involves relatively hi frequency sampling you also need memory, which regular arduinos have very little of. Also, not all HVACS work on the same IR frequency. There are several libraries around but from what I tried they seem to work on only very specific models or firms.
I truly don't see what you gain from your approach over using the remote as your transmitter, but whatever float your boat...

[CoolCooler]

Thanks, but this is not a normal HVAC, it is an in-window swamp cooler with a very simple 3-button remote. I am guessing the commands are PWM encoded so I can use a RasbPi to read them then emulate them. From what I have learned, the Arduino may not be fast enough for PWM frequencies required, so Pi it is.

My boat is floating fine. Using the hacked-remote approach is just adding in more things to go wrong. Reading and emulating it all with the one device makes for a tidy approach. And, decoding the IR is not that big a deal as I have the equipment to do it.

IF I wanted get really simple I could use RC-servos to push the buttons on the current remote. But again, I want to automate this all and that would just make a bigger mess. Keeping it all on the one processor board system, just makes more sense to me.

I don't have an Arduino, (I was going to buy one for this project, but I always research well before buying anything) but do have a Pi so I will use it.

I may buy an Arduino just to play with after this is working, but for now it looks like the Pi will be an easier approach.

[Moshe Livne]

@CoolCooler good luck! May the force be with you....