Ceiling Fan Adds CO2 Sensor

October 7, 2022 by Bryan Cockfield 18 Comments

Ceiling fans seem to be an oft-misunderstood or overlooked household appliance. As such, they seem to have missed a lot of the IoT wave. Sure, you can get smart controllers for them to plug into your home automation system of choice, but these mostly rely on temperature sensors, simple timers, or voice commands. There’s a lot more to a ceiling fan than maintaining a comfortable temperature, as [EJ] demonstrates with this smarter ceiling fan build.

A big part of the job of a ceiling fan is to improve air circulation, which can help a room from feeling “stuffy”. This feeling is usually caused by excess CO2 as a result of respiration in an area where the air is not moving enough to exhaust this gas. Not only does [EJ]’s controller make use of a temperature monitor for controlling the fan automatically, but there is also a CO2 sensor integrated to improve this aspect of air quality when needed.

The entire build is based on a Raspberry Pi Zero, and nothing needed to be changed about the ceiling fan itself for this added functionality because it already included a radio-based remote control. With some monitoring of the signals produced by the remote, the Raspberry Pi was programmed to mimic these commands when the surrounding sensors captured a condition where [EJ] would want the fan on. There’s also a manual control button as well, so the fan control is not entirely in the hands of the computer.

For a little more detailed information about this build, there’s a separate project page which details a lot of the information about the RF waveform capturing and recreation. And, if you want to take your fan to the next level, take a look at this one which focuses on building a smartphone app to control the fan instead.

Fan-tastic Misuse Of Raspberry Pi GPIO

April 6, 2021 by Stephen Ogier 36 Comments

[River] is a big fan of home automation. After moving into a new house, he wanted to assimilate two wirelessly controlled fan lights into his home automation system. The problem was this: although the fans were wireless, their frequency and protocol were incompatible with the home automation system.

Step one was to determine the frequency the fan’s remote used. Although public FCC records will reveal the frequency of operation, [River] thought it would be faster to use an inexpensive USB RTL-SDR with the Spektrum program to sweep the range of likely frequencies, and quickly found the fans speak 304.2 MHz.

Next was to reverse-engineer the protocol. Universal Radio Hacker is a tool designed to make deciphering unknown wireless protocols relatively painless using an RTL-SDR. [River] digitized a button press with it and immediately recognized it as simple on-off keying (OOK). With that knowledge, he digitized the radio commands from all seven buttons and was quickly able to reverse-engineer the entire protocol.

[River] wanted to use a Raspberry Pi to bring the fans into his home automation system, but the Raspberry Pi doesn’t have a 304.2 MHz radio. What it does have is user-programmable GPIO and the rpitx package, which converts a GPIO pin into a basic radio transmitter. Of course, the Pi’s GPIO pin’s aren’t long enough to efficiently transmit at 304.2 MHz, so [River] added a proper antenna, as well as a low-pass filter to clean up the transmitted signal. The rpitx package supports OOK out of the box, so [River] was quickly able get the Pi controlling his fan in no time!

If you’d like to do some more low-cost home automation, check out this approach to using a Raspberry Pi to control some bargain-bin smart plugs.

Reverse Engineering A Ceiling Fan Remote

March 31, 2020 by Rich Hawkes 2 Comments

In the quest to automate everything in your home, you no doubt have things that aren’t made with home automation in mind. Perhaps your window AC unit, or the dimmer in your dining room. [Seb] has several ceiling fans that are controlled by remotes and wanted to connect them to his home automation system. In doing so, [Seb] gives a good overview of how to tackle this problem and how to design a PCB so he doesn’t have a breadboard lying around connected to the guts of his remote control.

There are several things [Seb] needs to figure out in order to connect his fans to Home Assistant, the home automation system he uses: He needs to determine if the circuit in the remote can be powered by 5 or 3.3 V, he needs to connect the circuit to an ESP32 board, and he needs to figure out if he can create a custom PCB that combines the circuit and the ESP32 into one. The video goes through each of these steps and shows the development of each along the way.

There’s a lot of info in the video, so it might need to be slowed down a bit to see all the details. There are some other reverse engineering of home automation gear on the site, here, or, you might want to build your own remote to control your automated devices.

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Turn A Ceiling Fan Into A Wind Turbine… Almost

June 30, 2019 by Bryan Cockfield 9 Comments

It’s not uncommon to drive around the neighborhood on trash day and see one or two ceiling fans haphazardly strewn onto a pile of garbage bags, ready to be carted off to the town dump. It’s a shame to see something like this go to waste, and [Giesbert Nijhuis] decided he would see what he could do with one. After some painstaking work, he was able to turn a ceiling fan into a wind turbine (of sorts).

While it’s true that some generators and motors can be used interchangeably by reversing the flow of electricity (motors can be used as generators and vice-versa) this isn’t true of ceiling fans. These motors are a type called induction motors which, as a cost saving measure, have no permanent magnets and therefore can’t simply be used as a generator. If you make some modifications to them, though, like rewiring some of the windings and adding permanent magnets around them, you can get around this downside of induction motors.

[Giesbert] does note that this project isn’t a great way to build a generator. Even after making all of the changes needed to get it working, the motor just isn’t as efficient as one that was built with its own set of magnets. For all the work that went into it, it’s not that great of a time investment for a low-quality generator. However, it’s interesting to see the theory behind something like this work at all, even if the end result wasn’t a complete wind turbine. Perhaps if you have an old ceiling fan lying around, you can put it to better use.

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A Tinfoil-Free Internet Of Ceiling Fans

June 8, 2018 by Dan Maloney 9 Comments

Putting everything on the Internet is getting easier and easier, what with the profusion of Internet-ready appliances as well as cheap and plentiful IoT modules to integrate legacy devices. Think IoT light bulbs, refrigerators and dishwashers that can be controlled from a smartphone, and the ubiquitous Sonoff modules. But once these things are on the net, what are they talking about? Are they saying things behind your back? Are they shipping data about your fridge contents off to some foreign land, to be monetized against your will?

Maybe, maybe not, but short of a tinfoil helmet the only way to protect yourself is to build your own system. This IoT control for ceiling fans is a good example, with the added benefit that most wireless ceiling fan remotes are kind of lousy. [microentropie] didn’t like the idea of going the Sonoff route, so his custom controller is based on that IoT workhorse, the ESP8266. There are two versions, one switching the light and fan loads with relays, and one with triacs. The ESP serves up its own web page for control rather than using a cloud service, and is capable of setting up the fan to turn on and off automatically at preset times or temperatures. Everything sits in an unobtrusive box on the ceiling near the fan, but we bet this could be miniaturized enough to fit right inside the fan housing.

If some of [microentropie]’s code looks familiar, it might be because he borrowed it from his IoT rice cooker project.

Wall fans for circulating hot ceiling air

Winter Is Coming: Keeping Heat Where It’s Needed

September 10, 2017 by Steven Dufresne 19 Comments

If your workshop has ceilings as high as [Niklas Roy]’s 3.6 meters (11.8 feet), then you’re familiar with his problem. Hot air rises, and there it usually stays until the heat is transferred outdoors. But in the winter time we need that heat indoors and down low. One solution is to install ceiling fans that blow that hot air back down. However, [Niklas] often builds tall things that would collide with those fans. And so he had to hack together some wall hugging fans which will be both high up and out of the way.

For the fans he’s using six of those ubiquitous standing fans, the ones that normally sit on a post a few feet off the ground and swivel back and forth. Discarding the posts, he mounted the fan bodies to a horizontal wooden frame with a wheel attached to one end, one that he’d made for another project. A rope around the wheel, and hanging down, makes it easy to tilt the fans. For controlling the fans, a friend had given him an old industrial controller, and opening it up, all he saw was corrosion. Cleaning it all out he installed an old Russian 3-position switch from his collection.

In the future he’d like to add a closed-loop control system that would not only turn the fans on and off but also adjusting their speed. For now, however, he reports that it works really well. Check out his page for build photos and more details.

Meanwhile, winter really is coming to these northern latitudes and so here are more hacks to prepare you. For automated shovelling snow, how about an RC controlled 3D printed snow blower. And while you’re snug and warm inside remotely controlling your snow blower, you can still be getting exercise using a DIY bicycle roller. But if you do venture outside, perhaps you’d want to zip around on a dogless dog sleigh.

Repurposing A Ceiling Fan Into A Pottery Wheel

September 14, 2013 by Todd Harrison 29 Comments

The wheel goes round and round as does [Lou Wozniak]. He’s come back to us, this time hacking together a pottery wheel from a cheap ceiling fan. This is a great use for a discarded or inexpensive fan and the build should cost less than $50. As you watch the video you learn that repurposing the ceiling fan was no simple feat. Lucky for us [Lou] spins through detailed construction procedures and doesn’t fail to cover every tip and trick. He really does think outside the box or should we say inside the bucket and peanut butter jar. The fan gets dismantled as well as rewired inside a 5 gallon bucket which is used as the pottery wheel housing and stand. A plastic peanut butter jar was used as a makeshift electrical junction box inside the bucket. He remounted the motor’s string operated speed switch on the side of the jar and routed the pull string out the side of the bucket. The fan motor should have three or four switch speed settings which might be enough control. If continuous variable speed control is desired he could add in a controller similar to [Ben Krasnow’s] AC controller using one pin on a microcontroller. UPDATE: [AKA the A] tells us in a comment below that this controller won’t work with a ceiling fan, but we still really like [Ben’s] project so we’re leaving this link here.

Most potters use significant amounts of water to wet the clay while they throw, so we have reservations about having the high voltages and open motor design directly under the wheel with no shielding. We know [Lou] could easily hack in a splash pan and of course always plug into a ground fault protected receptacle when using electrical appliances around water.

We do get to see the wheel in operation at the end of the video, which you can watch after the break. However, [Lou] makes no claims at being a pottery artisan.

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