‘There’s a sucker born every minute” -P.T. Barnum
This morning we’ve been having a heated discussion at the Hack a Day offices (read: legion of doom) over Dyson’s new offering, a “bladeless fan”. At first this seemed extremely exciting, but how is the air being moved? We were hoping for a device operating via ionic wind but that’s simply not the case. Some of us think the bladeless claim is an outright lie, others understand it from a marketing stance, but we all agree: a fan with blades is still moving the air.
Dyson’s own information page states that “an energy efficient brushless motor” draws the air in with similar technology used in “superchargers and jet engines”, both of which use blades! The fan blades are in the base of this unit, they take in air and blow it out the ring. Just because you can’t see a fan, can we call our computers bladeless, or an air conditioner bladeless?
Enter the P.T. Barnum reference. Known as a man who could sell anything, his legacy lives on in the Dyson corporation. At 200 british pounds (~$320) for a ten inch desk fan, what are you getting that’s better than a traditional fan? The design supposedly amplifies the air movement fifteen times, but we’re skeptical about that figure as there’s no energy-saving claim to go along with such an incredible power boost. One thing is certain, you will NOT get a fan without blades for your sterling… just one with hidden blades plus a huge marketing campaign.
Hacking with Gum got their hands on one of the persistence of vision display fans that Cenzic was giving away at Blackhat this year. It’s not the biggest fan-based POV display we’ve seen but it’s still a fun device to tinker with. They hacked into the EEPROM on the device in order to change the message the fan displayed.
This is very similar to the other EEPROM reading/writing we’ve seen recently. Hacking with Gum read the data off of the EEPROM and then disassembled it to discover how the message data is stored on the chip. This was made easier by noting the messages displayed when the fan is running. The first byte of data shows the number of words in the message, then each chunk of word data is preceded by one byte that represents the number of letters in that work. Data length was calculated based on the number of pixels in each display character. Once he knew the data-storage scheme, it was just a matter of formatting his own messages in the same way and overwriting the chip.
This is a great write-up if you’re looking for a primer on reverse engineering an unknown hardware system. If you had fun trying out our barcode challenges perhaps deciphering EEPROM data from a simple device should be your next quest.
[Seth King] sent in his latest hack where he used an Arduino to regulate various aspects of a greenhouse. He has sensors for soil and air temperature as well as light and moisture. He built a custom circuit that uses relays to power fans, lights, and heaters. Using timers and the sensor data, the devices can be triggered to create the perfect environment for sprouts. He hopes to make the whole thing wireless by integrating XBees, but for now he ran a USB cord to his computer.
Related: Automatic grow light
We know some of you are getting sick of POV projects, but this one was just so cool, we couldn’t resist. [UncleBone] thought POVs were pretty cool, and wondered if he could use one on his ceiling fan. It would have been a breeze just to toss something like the RGBike POV on there and call it finished, but he designed his own. Opting to blow away the norm of using a single row of LEDs, he chose to do 5 different rows of LEDs, one for each blade. The whole thing is controlled by an Arduino, with a spreadsheet for image manipulating. Unfortunately, we don’t see any source files for the project available. Maybe he’ll put them on there if we ask really nicely. If he could get it playing animations, we would just chill and watch it for hours.
[Andrew] lives in Hawaii where the climate usually doesn’t necessitate heating and cooling systems. Usually, some open windows and doors will cool the house down enough. This relies on the breeze though, and that isn’t always there. [Andrew] came up with the solution of automating an attic fan to circulate air depending on outside temperature. Sure, he could have just installed a fan with a switch, but he wanted it to do all the work itself. He used a PIC16F877 as the brains and made the pretty control panel shown above.
On the seventh anniversary of the events of September 11, 2001, it’s important to reflect on patriotism, nationalism, and responsibility to your country and motherland. This USB memorial lets us think about our contributions to our great nation. Or it’s just a tribute to misguided nationalism and capitalism via insipid flag waving. Instructions are available at Instructables.
When I built my LumenLab projector, I used a thermal switch to run the fan. This simple control circuit looks like a nice alternative. The circuit is a simple adjustable temperature triggered Fet. If you know the resistance needed, you can replace the potentiometer with a cheap resistor. (You’ll want to use a DC fan)