Here is a small home-automation project that I have been working in my free time. I wanted to control my home-made air source heat pump system (based on Daikin FTX71GV / RX71GV ) from anywhere with Internet access. That would allow me to control my house’s heating/cooling remotely and more interestingly I could create scripts that turn the heating up/down based on outside temperature, time of day, inside average temperature and other criteria. All this to make a more efficient energy use, therefore a greener energy plan.
The example can easily be adapted to other air conditioner manufacturers by decoding their IR protocol.
The example can easily be adapted to other air conditioner manufacturers by decoding their IR protocol.
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My Daikin uses an ARC433** series remote control, so the analysis was done for that particular IR remote.
I had a NaNode laying around, so the hardware part was pretty much figured out. Just needed an 940nm IR diode, couple resistors, a transistor and I was all set.
Next, I had to decode the IR protocol of Daikin air condifioners. That was quite a challenge as it turned out. To do this I needed to capture the IR signal and reverse-engineer it. Since I have no oscilloscope, I used my sound card as described in this article. I used audacity and spent few days poking by eyes analyzing the waveform. There are few articles on the Internet that helped me also, but none was about the IR protocol for my specific Daikin model. As it seems, there are at least three protocols used by that manufacturer.
The IR frame is split in two parts 3000us apart. Quite strange approach, I think it it done to confuse universal IR learning devices. In fact I also tried to learn the codes using a SilverCrest universal remote, but it fails due to the gap between transmissions.
So after I had the IR protocol figured out, I had to put up the software. I used Ken Shirriff’s IR library and modified it so that it takes Daikin’s protocol.
I had a NaNode laying around, so the hardware part was pretty much figured out. Just needed an 940nm IR diode, couple resistors, a transistor and I was all set.
Next, I had to decode the IR protocol of Daikin air condifioners. That was quite a challenge as it turned out. To do this I needed to capture the IR signal and reverse-engineer it. Since I have no oscilloscope, I used my sound card as described in this article. I used audacity and spent few days poking by eyes analyzing the waveform. There are few articles on the Internet that helped me also, but none was about the IR protocol for my specific Daikin model. As it seems, there are at least three protocols used by that manufacturer.
The IR frame is split in two parts 3000us apart. Quite strange approach, I think it it done to confuse universal IR learning devices. In fact I also tried to learn the codes using a SilverCrest universal remote, but it fails due to the gap between transmissions.
So after I had the IR protocol figured out, I had to put up the software. I used Ken Shirriff’s IR library and modified it so that it takes Daikin’s protocol.
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