I posted to hackaday.com
http://hackaday.com/2010/07/05/wireless-garage-door-indicator/
[Sixerdoodle's] garage door indicator tells him if the door is open or closed. He was inspired by the hack from last September but wanted to make it wireless. The setup uses an RF transmitter/receiver pair from Sparkfun, each controlled by an ATtiny13 microcontroller. We found his battle with RF interference from other devices to be interesting. Working out those bugs made for a great learning experience.
July 5 2010, 12:00pm | More »
I posted to hackaday.com
http://hackaday.com/2010/07/05/reverse-engineering-an-rf-clicker/
[Travis Goodspeed] has pulled apart a TurningPoint response card, which is an RF device for answering quizzes, attendance checks, and casting votes in a classroom setting. After tearing it apart, he set out to reverse engineer it and managed to get quite a lot done. At this point he can spoof cards, so he could fake his or several people’s attendance. He can also sniff the packets as they are sent, opening up a plethora of opportunities to mischief. The one that was mentioned in the tip line was to simply repeat the answer that was most often sent for the quizzes. The writeup is very detailed and has great pictures. Good job [Travis].
[thanks Springuin]
July 5 2010, 11:00am | More »
I posted to hackaday.com
http://hackaday.com/2010/02/08/ez430-home-automation/
[Oliver] has been doing some work to use his TI ez430 Chronos wristwatch for some home automation. He’s working with a RF controllable lightbulb adapter which operates in the 433 MHz band. A dirt-cheap breadboard-friendly transmitter is available from Seeed Studios and he uses this in conjunction with a computer and an Arduino. Before the trolls get to their thing, YES, this is incredible overkill. But remember that he’s prototyping. We hope that if he intends to actually use this setup he’ll migrate to something like an ATtiny2313 running V-USB. Better yet, you should be able to tap into the watch’s companion receiver and cut the computer out completely.
If you’re easily amused you’ll appreciate the video of a light turning on and off after the break. If you’re a little harder to please then take a look at Oliver’s methods of using Python processing for the watch’s data.
Ok, now we’ve seen this watch turning on lights and unlocking doors. What else ‘ya got?
February 8 2010, 1:07pm | More »
I posted to hackaday.com
http://hackaday.com/2009/12/27/hackaday-links-december-27-2009/
Brain Controlled Game
If you’re a fan of biometrics this game is for you. It uses a homemade EEG to facilitate simple control. This is along the same lines as the Force Trainer hacks but this homebrew hardware is fun to look at. The success of the project can be seen in the video of a simple game they developed.
RF Camera Remote
[Jonny] wanted to trigger his Nikon camera remotely but was unhappy with the functionality of the IR remote. He hacked together an RF remote and receiver that still uses the IR functionality of the camera, but allows for the geographic freedom of Radio Frequency. Not as advanced as some we’ve seen but it meets his specifications.
CNC Mill
[Jan] tipped us off about a CNC mill that her friend made. The machine turned out beautifully even though very few tools were used to produce it. We love to pour over these builds so if you’ve done one, document it and send it in.
Neutering the On Demand Button
[Dan] hated his Comcast remote because the On Demand button could be hit by mistake. This was usually when trying to unpause live TV. The remainder of the show couldn’t be viewed just because the On Demand menu launched. Simplicity is king. He fixed this by placing two small paper rolls between the button and the circuit board. This way the button can still be used but only if you press pretty hard.
December 27 2009, 11:50am | More »
I posted to hackaday.com
http://hackaday.com/2009/12/17/static-bleeder/
When you are in the middle of the desert, pretty much every solution to a mechanical or electrical problem is a hack. [Sgt.M] who was deployed in Iraq sought out the help of radio guru [H.P. Friedrichs] about a static problem he was having. When dust storms would blow in strange things would happen in camp. Humming and crackling could be heard and [Sgt. M] actually had an electrical arc from a lamp to his hand at a distance of about 2 feet.
[Friedrichs] helped him find the problem. Their antennae were acting as static electricity collectors in the dust. All that dust friction in the dry air constantly built up a charge. The solution was simple, discharge the electricity at the antenna when it isn’t in use. Several solutions are outlined on the page, so check them out.
December 17 2009, 10:00am | More »
I posted to hackaday.com
http://hackaday.com/2009/11/25/ti-sports-watch-for-hacking/
How would you like to have a 3-axis accelerometer, pressure sensor, temperature sensor, RF wireless, and an LCD screen in a development package? What if we told you that you can have it in the form factor of a wristwatch offering from Texas Instruments? How much would you pay for such a device? Quit guessing, you can pick it up for just $49 with an estimated delivery in mid-February of next year.
Our tip-line has been packed with emails about this since it was announced on Monday. The device ships with the firmware to serve as a sports watch with heart rate monitor. The price is pretty good just for that functionality but this package also includes a USB programming and emulation dongle so that you can develop your own firmware. It looks like the included development software is written for Windows but we’re hoping you can get it running on other platforms as well.
The LCD is a segment display, so you won’t see DOOM running on board. That said, we expect your first project to turn this into a wireless controller using the buttons and accelerometer.
November 25 2009, 10:55am | More »
I posted to hackaday.com
http://hackaday.com/2009/11/20/remote-uses-no-batteries/
How often do you change the batteries in your television remote control? Yeah, basically never. But that’s a tribute to how efficient the device is and not a reason to overlook this development. NEC is showing off a remote control that uses no batteries. Power is generated using the piezo effect that occurs when a button is pushed. That is to say, when a crystal is compressed it emits a tiny bit of electricity which is harnessed and used to power this device. This is the same principle that is used in the electricity producing sidewalks tested in Japan.
It’s pretty phenomenal that they can run the device using this method. Right now there’s only a handful of buttons but we’re sure there’ll be advances in the technology. There’s a ton of use for this if it can be miniaturized. It is using radio frequency instead of infrared, making it a useful development in wireless doorbells, garage door openers, key-less entry fobs for your car, and many more applications.
[Thanks das_coach]
November 20 2009, 10:52am | More »
I posted to hackaday.com
http://hackaday.com/2009/10/14/add-a-key-fob-opener-to-your-door/
It seems like creating an automatic dorm room door opener is a rite-of-geek-passage each fall. [Adam], a student at Vassar, passed with flying colors by creating this clean setup. We’ve got video, more pictures, and a description after the break.
Above we see the device mounted on the inside of the door. The larger box houses a printer head carriage that does the physical turning of the handle. When the carriage moves from right to left it pulls a string attached to a long lever on the door handle (seen in the picture at the top of the post), providing the turning motion. Below this box is the control circuitry that we’ll look at next.
Here we have the brains of the operation. In the project box on the left is a board that takes care of the wireless fob communications. [Adam] tells us this works from about 250′, uses a roll algorithm over RF for security, and has a dedicated 12v DC power supply. In the middle is the timer circuit that controls the motor operation, with four 9v batteries providing the motor with power.
Motor control is provided by a timing circuit using three 555 timer ICs. [Adam] based his design off of a two chip delay circuit but scaled it up to three to give him more options. The circuit is responsible for driving the motor until the latch is open, holding for a set amount of time, then returning the motor to its original position.
Because he’ll be moving out at the end of the year, [Adam] wanted to make the system easily transportable. He’s used a jack system so that the controller can be mounted either above or below the motor unit at his next residence.
This works well and with the covers on the project boxes it’s not the duct-tape mess of the last door opener we saw. Nice work!
October 14 2009, 1:30pm | More »
I posted to hackaday.com
http://hackaday.com/2009/08/08/tiny-bluetooth-teardown/
The folks at SparkFun were startled by how small USB bluetooth adapters had become so they split one open. They noted a few interesting design features. It has a small folded trace antenna on the board edge. The metal USB housing acts as the RF shield. The bluetooth IC is an AS3620QA. Now we wonder what those tiny Buffalo drives look like inside.
Related: Eye-Fi teardown, storage/WiFi in an SD card
August 8 2009, 5:30pm | More »
I posted to hackaday.com
http://hackaday.com/2009/02/02/mobile-rfid-scanning/
[Chris Paget] is going to be presenting at ShmooCon 2009 in Washington D.C. this week. He gave a preview of his RFID talk to The Register. The video above demos reading and logging unique IDs of random tags and Passport Cards while cruising around San Francisco. He’s using a Symbol XR400 RFID reader and a Motorola AN400 patch antenna mounted inside of his car. This is industrial gear usually used to track the movement of packages or livestock. It’s a generation newer than what Flexilis used to set their distance reading records in 2005.
The unique ID number on Passport Cards doesn’t divulge the owners private details, but it’s still unique to them. It can be used to track the owner and when combined with other details, like their RFID credit card, a profile of that person can be built. This is why the ACLU opposes Passport Cards in their current form. The US does provide a shielding sleeve for the card… of course it’s mailed to you with the card placed outside of the sleeve.
Technology exists to generate a random ID every time an RFID card is being read. The RFIDIOt tools were recently updated for RANDOM_UID support.
[Thanks Zort]
February 2 2009, 8:43pm | More »
I posted to hackaday.com
http://hackaday.com/2009/01/29/uhf-power-harvesting/
[Alanson Sample] and [Joshua R. Smith] have been experimenting with wireless power transfer for their sensing platform. Their microcontroller of choice is the MSP430, which we used on our e-paper clock. They chose it specifically for its ability to work with low voltages and they discus its specific behavior at different voltages. The first portion of their paper uses a UHF RFID reader to transmit to the sensor’s four stage charge pump. They added a supercap to provide enough power for 24 hours of logging while the node isn’t near a reader. For the second half of the paper, they use a UHF antenna designed for digital TV with the same circuit and pointed it at a television tower ~4.1km away. It had an open circuit voltage of 5.0V and 0.7V across an 8KOhm load, which works out to be 60uW of power. They connected this to the AAA battery terminals of the thermometer/hygrometer pictured above. It worked without issue. The thermometer’s draw on a lab power supply was 25uA at 1.5V.
It’s an interesting approach to powering devices. Do you have an application that needs something like this? For more on wireless power, checkout this earlier post on scratch building RFID tags.
[via DVICE]
January 29 2009, 6:40pm | More »
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