Some home automation, although this is my home away from home we're talking about here. At our cottage we have a Panasonic heat pump, now about 10 years old so at point it is up for replacement (I asked for service for it and technician pretty much told us that there's no point, when it stops working you just replace it).
For now I have used some remote controlled sockets (with good results) to control heating there. Direct heat is somewhat expensive though, and using said heat pump to do it would be more cost-effective. The problem is that it is controlled by proprietary IR remote, so I can't just tell it to switch to "+20C heat" ..
Or can I?
I wanted to replicate IR with hardware I have already - effectively same I used for RF stuff. My idea had basically two steps;
1) Receive and decode code send by IR remote
2) Replicate said code.
Seems so simple. It turned out to be much less so.
My original idea was to make a simple IR receiver module (easy, there's plenty of schematics on net) and record sequence. IR signal has usually carrier (IR being turned on and off, generally at 40-80 kHz range) and data is modulated on top. In this case it (I found out after building signal receiver) was 75kHz-ish modulation, with PWM on top of it, starting with longer preamble.
My original idea was to modify same code I had used as RF receiver to serve as IR receiver. Well, long story short, that did not work. RF receiver module did AM decoding, so I was receiving (relatively) clean 1 or 0 data, and only had to decode from there. IR didn't. I was receiving that carrier signal directly. And as it turns out, software was not fast enough for clean reception. It lost pulses too often to be reliable, so that idea was out.
That was last autumn. I ran out of time, winter was coming so I had to install system as-is to have even current control over it (and oh boy has it been great even at its current state; it dropped my power usage by full two thirds since system can keep direct electric heating off when it's warm enough outside for heat pump to manage alone).
I couldn't drop the idea of heat pump control however... (this is to say; to be continued)
