RF hacking my cloud-controlled ceiling fan

https://samwilkinson.io/posts/2026-06-24-rf-hacking-dreo

by sammycdubs • 29 days ago

64 20 29 days ago

Good write up Sam!

Love these write-ups, i have various 433mhz things around the home that i’ve integrated with home assistant. Probably the most useful is still a bbq thermometer with multiple probes.

Anyway i was going to post my favourite tool in this space https://github.com/jopohl/urh universal radio hacker just makes the process trivial, but i see the repo is marked archived now. Either way, the software is excellent.

sammycdubs4• 22 days ago

I forgot to mention I used URH, it’s such a good tool. Very approachable for something so specialized.

artisinal4• 22 days ago

I do not have a home so perhaps I do not fully understand. If it is warm when I go to bed, I turn on the ceiling fan by rotating the knob next to the bed. When I wake up, I turn it off. What kind of automation are you looking for?

MayeulC2• 22 days ago

Not OP, but I can imagine piloting it with a temperature sensor: too warm=>increase speed. It could avoid some sweat-covered wake-ups, depending on the circumstances (trade it for a noise-triggered wake-up, perhaps).

Another use-case I have for this is in a house where the mezzanine gets much warmer than below when heating during winter: detect this with a couple of temperature sensors and turn the fan on when needed.

sammycdubs4• 22 days ago

For the fan - I like having it turn on in the late afternoon to freshen up the air in the bedroom.

I also really like automatically adjusting the brightness/color temperature of all our lights during the day.

It’s by no means necessary, but I don’t want to go back now.

artisinal4• 22 days ago

Thanks. I typically turn on the lights with a wall mounted switch when I walk into a room and turn it off when I leave the room. Never gave brightness or color temperature much thought.

wpm• 22 days ago

I mean, is it that hard to imagine that someone doesn't have a knob next to their bed?

Also, I've maybe seen a speed control knob for a ceiling fan a few times in my life in the US. Here it's all pullchains, or more recently "smart" bullshit.

artisinal4• 22 days ago

I am European and every ceiling fan I have used has a wall mounted knob. It is very convenient. Could be a regional difference.

MayeulC2• 22 days ago

Funnily enough, I did almost exactly that last week, but I kind of gave up for now as my 433 MHz transceiver does not seem to work well with esphome? It does seem to output signals when I use the remote. Oh well, I will revisit when I have more time.

A major difference is that I relied on a flipper zero I had to do the 433 MHz capture instead of an RTL-SDR (I have one too, but have not needed it yet).

For reference, the transceiver is the one that came with this product: https://www.athom.tech/blank-1/8ch-inching-self-lock-relay-f... (which I already use for controlling a heater). Weirdly, it is not listed in the official esphome config (possibly because RF is a recent addition to esphome). My next step is to test it on another esp board & compare timings with what esphome generates.

I should start doing write-ups too. I came across quite a few interesting sources during this mini project (2-3 hours max).

sammycdubs4• 22 days ago

I’m really interested in the Flipper Zero, for your use was it capturing specific encoding or raw data?

ainka-ainka• 22 days ago

I'm working on there exact path since a few months to make this process feel magical to people who can run Home Assistant, but rf capture and replay is too technical. I'm using evilcrow-rf for it and goal is to provide trivial setup flow so that copying rf remotes feels easier than signing up with the company you bought your device from. Hopefully I'll be able to do a show hn in near future.

https://github.com/meowtochondria/EvilCrowRF-V2

latchkey• 22 days ago

I bought a cheapo tuya wifi fan controller for a "dumb" ceiling fan. Connect to it from SmartThings app on my phone. The app can be paired with siri and now I can just say: "living room fan on/off". Works great.

sevennull• 22 days ago

Thanks for sharing - i have been on a few years long journey trying to control my swamp cooler while try to learn RF. I started with a flipper zero to see if i could even capture signals from remote, replay and then decode via URH. i was able to brute force my way through it with older AI models 'back in the day'. I had it basically just send a 'cool' signal while remote was set to vent (which means no water flow).

The humidity in the house could then be measured with a RH sensor and the controller could then send cool signal to add some water to the pads if RH dropped below a certain point. This keeps the humidity way down while only increasing temp by 1-2 degrees. So much more comfortable as i can now keep the RH in the 50-60% range base on outside conditions.

I recently picked the project back up and with newer Claude models i have been making significant progress. For one, the code to determine when to 'cool' is getting better at managing as outside conditions change - temp/RH etc outside impacts cooler performance. Second, I can now start to fully replace the remote so the code manages via feedback loop. the remote has a keep alive sync signal that i was able to figure out that prevented me from using just the eps32. if the remote was off, the controller would turn on the cooler fine but if i didnt send a keep alive, the cooler eventually shuts off.

I have also added a RX module that allows me to now listen for the remote signal and shut off controller when i turn off via remote. eg turn on cooler via remote and controller can be turned on/off to work its magic.

Ultimate goal is to maintain the RH in house all day while outside conditions vary - morning, afternoon, evening and storms etc and then turn off at night once certain conditions are met. My wifes request is to have it turn off at bedtime so she can fall asleep, then turn back on after about 1 hour - so a timer is future feature.

The one thing I have learned is RF is hard but satisfying to figure out - I would have never attempted learning this w/o Claude. I also have a meter reader esp32 i am still working to debug and feel confident i can figure it out.

illright• 22 days ago

Thanks for the write-up, I've been interested in connecting RF-controlled devices to Home Assistant myself lately! Your experience will definitely come in handy :)

Are you following HA's latest push towards proxy devices? A few months back, they have been improving support for RF and infrared controlled devices through proxy hardware — as far as I understand, it lets you have just one RF transmitter in the home and have several integrations use it for sending their chosen commands on their chosen frequency, a sort of transport/logic decoupling. It's new, so there's not a lot of stuff that uses these proxies, but I want to play around with them and wanted to get them on your radar as well!

tehlike• 22 days ago

I imagine an RF copier / blaster could work too?

Something like this: https://www.aliexpress.us/item/3256812248263286.html?

I used IR version of this for my tv at some point even though it had an http interface, and it worked fine.

RF hacking my cloud-controlled ceiling fan

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