The idea here is pretty simple: use a remote temperature sensor to tell a fan located behind the fireplace when it’s time to kick on and start sharing some of that warmth with the rest of the house. But as usual, it ended up being a bit trickier than anticipated. For one, when [Ben] took a close look at the Vornado 660 fan he planned on using, he realized that its speed controller was “smart” enough that simply putting a relay on the AC line wouldn’t allow him to turn it on and off.
So he had to do some reverse engineering to figure out how the Sonix SN8P2501B microcontroller on the board was controlling the fan, and then wire the Photon directly to the pins on the chip that corresponded with the various physical controls. This allows the Photon to not only “push” the buttons to trigger the different speeds, but also read the controls to see if a human is trying to override the current setting.
For the remote side [Ben] is using a Particle Xenon, which is specifically designed for Internet of Things endpoints and sensor applications. Combined with a TMP36 temperature sensor and 3.7 V 500 mAh battery, this allowed him to easily put together a wireless remote thermometer that will publish the current temperature to the Photon’s mesh network at regular intervals.
While we don’t yet know the long-term effects of hanging out around 3D printers, it doesn’t take a in-depth study to figure out that their emissions aren’t healthy. What smells toxic usually is toxic. Still, it’s oh-so-fun to linger and watch prints grow into existence, even when we have hundreds or thousands of hours of printing under our belts.
Most of us would agree that ABS stinks worse than PLA, and that’s probably because it releases formaldehyde when melted. PLA could be viewed as slightly less harmful because it has a lower melting point, and more volatile organic compounds (VOCs) are released at higher temperatures. Though we should probably always open a window when printing, human nature is a strong force. We need something to save us from our stubbornness, and [Gary Peng] has the answer: a smart 3D printer emission monitor.
The monitor continually checks the air quality and collects data about VOC emissions. As the VOCs become elevated during printing, the user is notified with visual, audio, and phone notifications. Green means you’re good, yellow means open a window, red means GTFO. There’s a brief demo after the break that also shows the phone interface.
The heart of this monitor is a CCS811 gas sensor, which provides VOC data to a Particle Photon. [Gary] built a simple Blynk interface to handle the alerts and graph historical VOC readings. He’s got the code and STLs available, so let this be the last time you watch something print in blissful semi-ignorance.
The project didn’t start with the noble aim of realizing the hidden and underutilized quiescent nature of a smoke alarm, though. He wanted his range exhaust fan to turn on automatically when it was needed during his (and his family’s) cooking activities. The particular range has four speeds so he wired up four relays to each of the switches in the range and programmed a Particle Photon to turn them on based on readings from an MQ-2 gas-detecting sensor.
The sensor didn’t work as well as he had hoped. It was overly sensitive to some gasses like LPG which would turn the range on full blast any time he used his cooking spray. Meanwhile, it would drift and not work properly during normal cooking. He tried disabling it and using only a temperature sensor, which didn’t work well either. Finally, he got the idea to tear apart a smoke detector and use its sensor’s analog output to inform the microcontroller of the current need for an exhaust fan. Now that that’s done, [Ben] might want to add some additional safety features to his stovetop too.
If you’re reading Hackaday, we’re willing to bet that you either own the LEGO Saturn V and Lunar Module models, or at the very least know somebody who does. Even if you thought you’d finally outgrown playing with little plastic bricks (a critical mistake, but one we’ll ignore for now), these two kits just have an undeniable appeal to them. You might never get a chance to work for NASA, but you can at least point to the Saturn V rocket hanging on your wall and say you built it yourself.
[Ben Brooks] thought these fantastic models deserved equally impressive stands, so he built “exhaust plumes” that both craft could proudly perch on. With the addition of some RGB LEDs and a Particle Photon to drive them, he added incredible lighting effects that really bring the display to life. There are also sound effects provided by an Adafruit Audio FX board, and for the Lander, an LCD display that mimics the Apollo Guidance Computer DSKY that astronauts used to safely navigate to the Moon and back.
In his write-up on Hackaday.io, [Ben] makes it clear that he was inspired by previous projects that added an illuminated column of smoke under the LEGO Saturn V, but we think his additions are more than worthy of praise. Playing real audio from the Apollo missions that’s synchronized to the light show honestly makes for a better display than we’ve seen in some museums, and he even rigged up a wireless link so that his neighbor’s kids can trigger a “launch” that they can watch from their window.
For the Lunar Module, he 3D printed an enclosure for the Photon and Adafruit quad alphanumeric display that stands in for the DSKY. There’s even lighted indicators for the 1201/1202 program alarms that popped up as Neil Armstrong and Buzz Aldrin descended to the lunar surface 50 years ago.
Many electric cars feature a timer capability that allows the owner to set which hours they want the vehicle to start pulling a charge. This lets the thrifty EV owner take advantage of the fact that the cost of electricity generally goes down late at night when the demand is lower. The Renault Zoe that [Ryan Walmsley] owns has this feature, but not only does it cost him extra to have it enabled, it’s kind of a hassle to use. So being an enterprising hacker, he decided to implement his own timer in the charger itself.
Now controlling high voltages with a lowly microcontroller might sound dangerous, but it’s actually not nearly as tricky as you might think. The charger and the vehicle actually communicate with low-voltage signals to determine things like the charge rate, so it turns out you don’t need to cut into the AC side of things at all. You just need to intercept the control signals between the two devices and modify them accordingly.
Or do you? As [Ryan] eventually realized, he didn’t need to bother learning how the control signals actually worked since he wasn’t trying to do anything tricky like set the charge rate. He just wanted to be able to stop and start the charging according to what time it was. So all he had to do was put the control signal from his car through a relay controlled by a Particle Photon, allowing him to selectively block communication.
The charger also had an optional key lock, which essentially turns the controller off when the contacts are shorted. [Ryan] put a relay on that as well so he could be absolutely sure the charger cuts the juice at the appropriate time. Then it was just a matter of getting the schedule configured with IFTTT. He mentions the system could even be tweaked to automatically control the charger based on the instantaneous cost of electricity provided by the utility company, rather than assuming overnight is always the most economical.
Home brewing is a pastime that can be as much an art or a science as you make it, depending on your predilections. [Brandon Satrom] is one who leans very much towards the science side. There’s plenty that can be done to monitor and control a brew, and [Brandon] is one of many who have built custom hardware to help get the best possible results. Now, that hardware was due for an upgrade.
[Brandon]’s original BrewBuddy system relied on the Particle Photon, a useful platform that was nonetheless getting on in years. With the launch of the new Particle Argon, [Brandon] set his sights on new features that were possible with the added horsepower available. Graphics were added to the LCD screen, and a piezo sensor to detect the start of the fermentation process. This is in addition to the original temperature monitoring and plotting features of the first build.
The upgrade from one microcontroller platform to another can be fraught with headaches, but in this case, only minor changes were needed. 3 lines of code were changed to account for different pin assignments, and the rest fell neatly into place. It’s a testament to the compatibility of the Particle platforms that this upgrade was so easy.
The build relies on a Particle Photon to do the heavy lifting of connecting the door to the Internet. Particle offer a cloud service that makes setting up such a project easy for the first timer, and [Brad] was able to get things working quickly. A relay is used to activate the garage door remote button, as it was desired to leave the main control board of the garage door opener untouched. Reed switches are used to sense the position of the door, and [Brad] coded a state machine to ensure the door’s current state is always known.
It’s a simple project, but [Brad]’s use of state machine techniques and position sensing mean it’s less likely he’ll get home to find his garage open and his possessions missing. If you’re new to programming simple physical devices, you could take a page out of his logbook. Of course we’ve seen similar builds before, like this one from parts from the scrapbin.