[Marcel] Wondered if he had more control over the ventilation system in his house? You can add some Nifty features, such as automatically ventilating your home in the morning when everyone is away, only making noise when no one is listening. Sadly, most ventilation systems aren’t automation-friendly at all – but he was lucky, because his system came with a wireless remote. [Marcel] Reverse-engineer this remote, create a USB dongle called the same protocol and tie it to its home assistant setup!
The remote in question is the Orcon R15, which communicates with a CC1101 chip via an Atmel MCU SPI. He sniffed the SPI contacts by pressing various buttons, compared the recordings, extracted the protocol, and created a test setup with an additional Arduino and CC1101 module. It worked, and he started designing a separate dongle using an ATMega32U4. The dongle is quite neat to look at, and fits the Hammond fence – what’s not to like?
He then embarked on a journey to develop firmware and was not disappointed on that front either. Its code does not fully mimic the original remote in terms of control, it also has a user-friendly pairing flow, monitors the current state of the system and still allows the original remote to be used in parallel. Eagle files for PCB are available on the project page, code and a PDF schematic available in the GitHub repo. This entire journey is described on the Hackaday.io page, and we recommend that you check it out for all the insights it provides!
Ventilation systems are not designed for automation and it is nice to see hackers working to conquer this frontier. The last time we saw a ventilation system hack, it had the added challenge of being homeowner-friendly, and we think the hacker nailed it!