Rage Against the Alkaline Remote (Ratar) — an open-source RF capture/replay device (CC1101 + XIAO ESP32-C6), built for ESPHome
Frustrated by the Broadlink RM4’s unreliability, the high cost of the Bond bridge and Athom’s limited RF frequency (433Mhz-ONLY), I set out to build a simple open source device that could handle multiple RF frequencies at a sub-$10 cost. In my case, the purpose was to control my Minka-Aire ceiling fans at 304Mhz.
Neither of my fans’ remotes had any public protocol documentation anywhere, so the first step was capturing and reverse-engineering the raw RF codes myself with the CC1101 rather than relying on an existing database (though I did check a Flipper Zero SubGHz repo as a fallback first). It works at 304MHz, fixed-code ASK/OOK with both remotes fully decoded down to the bit level, including working out why one remote’s “reverse” button doesn’t actually exist on the RF side (its code would collide with an existing command).
I’ve captured all of the details on the Kicad custom PCB, the yaml code, and the OpenSCAD 3D printed case in a public Git repository:
GitHub - fpgirard/ratar · GitHub (Clone with --recurse-submodules — it pulls in Seeed’s KiCad footprint library.)
What’s in the repo:
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A custom KiCad carrier PCB (“RF-HAT”) that connects an off-the-shelf CC1101 to a Seeed XIAO ESP32-C6. Chosen for its built-in ceramic antenna, no external antenna is needed for the C6’s own WiFi/BLE
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A working ESPHome config using the official built-in cc1101 component (2025.12.0+). No hand-rolled SPI register writes needed
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A parametric OpenSCAD (BOSL2) two-part printed enclosure, bolted lid, antenna/USB-C cutouts
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Full pin assignments, reverse-engineering notes, and gotchas worth knowing (FCC-filing frequency vs. the common 315MHz assumption, dimming-via-long-press behavior, etc.)
Where this is headed: Ratar is narrow in scope today (two fan remotes), but it’s built to support a much larger idea: a universal, community-supported RF/IR transceiver, where the hardware, ESPHome YAML, and CAD files are shared and easy to extend to any 300–928MHz remote. I’m currently adding an IR LED/receiver to the board so the same device can also handle IR-controlled gear (TVs, AC units, etc.) alongside RF.
Lastly, I have a small batch of extra RF-HAT boards built. If you’d be interested in contributing to this — testing on your own remotes, adding protocol decoding, helping with the IR side, improving the KiCad schematic (it needs proper net labels, among other things) — I’m happy to send out 2 free units to folks willing to collaborate. In addition, I have a spare Ratar RF-HATs that I can send if anyone wants to solder their own ESP32-C6 and 8pin female headers to it. Reply here or open an issue on the repo if you’re interested.
Questions, feedback, and PRs all welcome as this is very much a “fly it as you build it” project at this stage.