I've got a wall mounted AC unit (kind of a mini-split setup) that uses an IR remote control for all operations. Here's what I don't like about it:
- There is no real on/off "thermostat" function. You can choose a temperature, but the unit will just run forever (cycle between AC or heat and fan/vent) until you turn it off.
- The remote is crappy, and you have to aim it very precisely to get a response.
- Interesting modes like dehumidify, different fan speeds, air flow direction, away/low power mode, etc (all things that could be very helpful), are useless since you have to manually change them all the time with the remote to get any effect, and nothing is automatic.
My idea is to make some kind of device I can program that will accept input (initially via usb or ethernet, but eventually via a small LCD with buttons), read temperature and humidity in the room, work all sorts of software magic (I'm a software developer by trade; I'll bring the magic) and send IR codes to the AC unit to manage it. I know I'll need the following:
- Some sort of programmable logic board (thinking the Arduino could be right for this)
- IR transmitter/blaster (preferably one with a cord so I can mount it directly to the front of the AC unit where the reciever is)
- IR receiver (temporarily only? Need to read in and make a database of every possible code the current IR remote can transmit)
- Temperature sensor
- Humidity sensor
- Small LCD with input buttons (eventually, not needed for initial config)
- This is a one way data flow; there is be no way to immediately tell if the device actually is doing what it should be. There are some wires that I can potentially tap into for extremely basic info, but the unit is under warranty and costs several thousand dollars.
- I don't know what type of IR signal the remote uses (what frequency, string length, etc), so I don't know what breed of receiver/transmitters I will need.
- I have never tinkered with an Arduino before; so no experience on my part (though my coding skills are strong)
I'd love to get some feedback on this plan, and maybe a point in the right direction on potential parts. I've been looking at the hardware options, and frankly I'm really confused.
Potential parts I've found so far:
Temprature and humidity sensors: DHT11 or DHT22 ($2.50 or $11; not sure if I really need the upgraded one)