RFID Reader Gets User Inputs And Smart Card Write Capability

February 9, 2012 by Mike Szczys 4 Comments

[Navic] added a slew of abilities to his RFID reader. It’s now a full-featured RFID reader and smart card writer with extras. When we looked at it last time the unit was just an RFID and smart card reader in a project enclosure. You could see the RFID code of a tag displayed on the LCD screen, but there wasn’t a lot more to it than that.

The upgrade uses the same project enclosure but he’s added four buttons below the display. These allow him to access the different features that he’s implemented. The first one, which is shown in the video after the break, allows him to store up to six tags in the EEPROM of the Basic Stamp which drives the unit. He can dump these tag codes to a smart card (pictured above), but also has the option of interfacing with a PC to read from and write to that card.

We don’t think you can directly write RFID tags with the device, but we could be wrong.

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Make A Wind Turbine From 55 Gallon Drums

February 9, 2012 by Jeremy Cook 34 Comments

Although there are several vertical axis wind turbines listed on greenterrafirma’s page, the one built with 55 gallon drums was especially interesting to us. Although the spouse approval factor of any of these designs is debatable, at $100, the 55 gallon drum design could provide a very good return on investment. The tools required to make one of these are relatively simple, so this could make this experiment accessible to those without a vast arsenal of equipment.

If large blue barrels aren’t your thing, the post also features several other turbine designs, including one made with wood and aluminium foil, and one constructed out of PVC pipe. The video after the break does a good job of explaining the “blue barrel” construction process, but if you’d rather just see this [VAWT] in action, fast forward to 5:25.

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Attiny25 Based Function Generator Causes A Wave

February 8, 2012 by Kevin Dady 11 Comments

Function generators are a handy bench tool to have around, and while you can usually cobble something together that works, it is much more handy to grab a device when you need it. Thats where this function generator sent to us by [Mohonri]comes in. Based around a ATTiny25 and a rail to rail op amp which is able to replicate frequencies from 1Hz to about 40KHz, in square, triangle, and sinewaves simultaneously.

The function generator also features independent amplitude control on each output. And it’s all on one palm-sized, single-sided PCB. The main part of the code is split into two parts: the main loop gets the inputs and constructs a waveform table in SRAM, and then an ISR reads that table and outputs it to one of the timers, which produces a PWM output, which is low-pass-filtered and then passes through a potentiometer (for amplitude control) and then to an op-amp before landing on a set of terminals.

Though its not 100% perfect, trading speed for a 6 bit resolution, it should be more than enough for most electronic projects. You can pick it up in kit form from the on-line shop, but schematics, software and PCB layouts are also available for download.

Designing A Smarter RF Transceiver

February 8, 2012 by Kevin Dady 3 Comments

Two months ago we featured a transceiver based on the Microchip MRF49XA, and a lot of feedback was sent to [hpux735] requesting that some brains be added onto the system. [hpux735] decided that if he was going to do it, might as well go the distance and make a make a native USB transceiver.

The prototype model is designed for use with the Atmel AT90USBKey, and uses the LUFA USB framework. The protocol and packet format was revised, and a Hamming Code implementation was built using look-up tables to give error control. Finally once the prototype was ready to go [hpux735] created some awesome little PCB’s that contain the AVR, radio, antenna hookups, and blinky lights (no project is complete without blinky lights) are all ready to go when you are.

This project has come quite a long way, covers 3 blog pages, uses a fair bit of ribbon cable, but you just got to love when a plan comes together.

Hackaday Links: February 8, 2012

February 8, 2012 by Mike Szczys 15 Comments

Most useless machine

We love ’em, and we hope you do too. Here’s [Phase2plus’] take on the most useless machine.

Scratching like it’s 1989

[Nick] spent three bucks at the thrift store and ended up buying days worth of fun with this cassette player. He hacked it to scratch like vinyl.

3D printed jawbone

This lady now has her own 3D-printed jawbone. We’re not talking about the Bluetooth headset… it’s an actual bone replacement! And yes, the skeleton for the Terminator was 3D printed… we’re that much closer now. [Thanks Steve]

Hexbug superbowl

Why not let robots decide our sports gambling choices? [Eric] let this slew of HexBugs battle it out as an early indicator for who would win the Super Bowl. Seems he has no shortage of the little toys, all of which received an MSP430 upgrade. The firmware actually implements obstacle avoidance, but he makes a poke at the Chicago Bears who seem to have the same mission.

Foil fix for worn out remotes

[Viktor] found an interesting repair tip. If you’ve got remote controlers whose buttons are not working so well anymore you may be able to fix them with tin foil. He uses a single-hole punch to clip out circles which are attached to the underside of the misbehaving button. Worth a try!

Single Hand Keyboard For Tablets

February 8, 2012 by Mike Szczys 27 Comments

To us it makes a lot of sense to hold the tablet in one hand and type with the other. That’s exactly how [Adam Kumpf] has implemented this one-handed typing interface which was originally conceived by [Doug Engelbart].

As you can see, there’s a large contextual area for each finger on your right hand. Letters and navigational keystrokes are input through this interface based on single touches, or combinations up to and including all five digits. This offers up 32 possible combinations (including all on and all off) which is enough to cover the modern English alphabet.

[Adam’s] demo page works for most tablets so give it a whirl. Yes, it works with iDevices too which is a surprise as we would have thought this was using Flash. If you’re not near a touch-sensitive device you can get the gist of the operation from the demo video embedded after the break.

Now, who’s going to be the first to make this into a replacement keyboard on iOS 5?

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Quadcopter Build Ready For First Flight

February 8, 2012 by Mike Szczys 9 Comments

[Abhimanyu Kumar] has been hard at work building and posting about his quadcopter. So far he’s published ten installments for this build, letting us relive the adventure vicariously. But it’s number 11 that we’re really excited about as he plans to share the first free-flight footage in that one.

The bug was planted in his brain after hearing that a quadcopter was used to shoot some of the footage in Spiderman 2. He wanted one to call his very own but the cost of a ready-made unit was out of his league. So he decided to build one instead. The first version uses aluminum bracket for the cross making up the motor mounts. He added LEDs to liven things up and even made a demo video of the thing tied to a table (no IMU yet so free flight would be fatal). After this stepping stone he decided to go with a Wii Motion Plus and Wii Nunchuck as the positioning feedback sensors. There is also a body redesign with helps lighten the load.

It’s a fun project, and we can’t wait to see where he goes from here!