Emulating A Student Clicker With An Arduino

November 16, 2012 by Brian Benchoff 20 Comments

When schools and universities have hundreds of students in a lecture course, they need a way to tell alumni and other potential benefactors that faculty/student relations are just as good as they were in the 1960s, when enrollment was just a fraction of current levels. Technology solves all problems, apparently, so administrators of these universities turn to ‘clickers’ – radio frequency remotes used to take attendance and administer quizzes.These clickers have absolutely no security, so it’s no surprise [Taylor Killian] was able to emulate one of these clickers with an Arduino allowing anyone with a laptop to cheat on a quiz, or have an entire class show up with only one student in the room.

Previously [Travis Goodspeed] (thanks for sending this in, [Travis]) tore apart one of these clickers – a TurningPoint ResponseCard RF – and discovered it uses a Nordic nRF24L01 wireless transceiver, commonly available on eBay for about two dollars.

[Taylor] connected this wireless module to an Arduino and whipped up a bit of code that allows him to listen to the audience responses, respond to a question as either a single clicker or all clickers, automatically respond with the most popular answer, and even block all audience responses to each question.

Perhaps technology doesn’t solve every problem, but at least [Taylor] learned something from a glorified remote control sold at the bookstore at an insane markup.

Roomba And Virtual Walls Make Up This Theme Family Halloween Costume

November 15, 2012 by Mike Szczys 7 Comments

It figures. You spend a ton of time making a cool set of costumes and then you can’t get your kid to pose for a picture. It’s okay though, we still get the point. This themed set of costumes dresses the little one as a Roomba vacuuming robot while mom and dad are suited up as virtual walls (modules that are used to keep the bot from falling down stairs, etc.). It’s fun and unique, but had it not been for some additional electronics this would have been relegated to a links post. For safety sake each costume was outfitted with a ring of LEDs. As a challenge, the lights were given the ability to sync up patterns with each other.

Each costume has a circular frame at the top with a set of RGB LED strings attached. To get them to display synchronized patterns an IR transmitter/receiver board was designed and ordered from OSHPark. Each costume has four of these modules so no matter where the wearers are facing it should not break communications. A demo of the synchronized light rings can be seen after the break

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Directing An Alarm System Straight To The Internet

October 16, 2012 by Brian Benchoff 23 Comments

[Scott] has a pretty nice alarm system at his house – it will give the operator at his alarm company enough information to determine if it’s a fire alarm, burglary, or just a cat walking in front of a sensor. [Scott] wanted to cut out the middle man and receive notifications from his alarm system on his phone. He did just that, with the help of a trusty Arduino and the very cool Electric Imp.

[Scott]’s build began with an Arduino attach to a Raspi to monitor state changes in the alarm system. Because the designers of the alarm system included a very helpful four-wire bus between the alarm panels and the part connected to the phone line, [Scott] found it fairly easy to tap into these lines and read the current alarm status.

Dedicating a Raspberry Pi to the simple task of polling a few pins and sending data out over WiFi is a bit overkill, so [Scott] picked up an Electric Imp Arduino shield to transmit data over WiFi. We’ve played around with the Imp before, and [Scott] would be hard pressed to come up with a cleaner solution to putting his alarm monitor on the Internet.

Now [Scott] has a very tidy alarm monitor that sends updates straight to his cell phone, no middle man required. A very neat build, and an excellent use of a very cool WiFi device.

Building A Tilt Rotor UAV

October 4, 2012 by Mike Szczys 17 Comments

We see a lot of quadcopters, and even the occasional octocopter around here. But this build does it with just two propellers. It’s a tiltrotor build which allows the two upward-pointing propellers to tilt forward and backward. The real world equivalent of this UAV design that pops to mind is the V-22 Osprey.

The motors are mounted on a beam running perpendicular to the direction of travel. Each of them is mounted on a bearing which can be rotated by a servo motor. They rotate independently of each other, which allows for yaw. Of course roll is controlled by driving the propellers at different speeds and pitch is adjusted by tilting both mounts at the same time.

[Stephen] mentions that the tiltrotor design has several advantages over its relatives that use more than two props. This design costs less to build, uses less electricity, and makes for an easier autopilot implementation. If you want to see it in the air, don’t miss the clip after the break.

This is just the second tiltrotor build we remember seeing. The other one was a Halloween prop.

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200 Pound, WiFi Deploying Robot Ran Over My Foot

October 3, 2012 by Brian Benchoff 28 Comments

[Adam Bercu] and [Dan Landers] from Artisan’s Asylum in Somerville, MA brought a very, very cool toy to Maker Faire this year. It’s a two hundred pound WiFi repeater deploying robot able to amble across unforgiving terrain and my foot.

The robot is controlled through a web interface with the help of a front-mounted web cam with pan and tilt controls. All the signals are sent through a WiFi connection to a node.js web server; not the best way to communicate with a robot over long distances, but [Adam] and [Dan] have a few tricks up their sleeve.

On the back of the robot are two Pelican cases loaded up with a battery and a Linksys WRT54G wireless router. When the robot reaches the limits of its range, it activates a solenoid, dropping a WiFi repeater. This repeater has enough battery juice to stay powered for about a day and a half, meaning the robot can make multiple trips to deploy a wireless network through some very hostile terrain. Perfect for disaster and search and rescue operations.

There are two videos after the break: the first is [Dan] going over the capabilities of his tank bot and the second is a short demo of the bot tearing up the grass at Maker Faire.

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Doorbell To Internet Bridge Also Useful For Other Home Automation

September 28, 2012 by Mike Szczys 5 Comments

This wireless doorbell hack can send a text message when someone rings. Adding the hardware to the chime unit turned out to be quite simple. It shows potential for a slew of other applications.

[Martin] started the project with a breakout board he had designed for an RFM12B wireless transceiver board. This board is popular because of its low-cost, small size, and ease of operation. [Martin’s] breakout is barely larger than the RFM module itself, and merely adds an ATtiny84 to the mix. In the case of this doorbell project he uses a pin interrupt to detect when the doorbell’s LED is illuminated. This wakes the chip from sleep and sends a message back to the receiver that something has happened.

The receiver can do anything it wants with that data. In this case it uses an email-to-SMS service to send [Martin] a text message. But the home automation applications are vast for this simple hardware. We have a water heater that is not near a floor drain so we use a simple leak detector to sound an alarm if there is ever a problem (the water heater sits in a shallow tray). That works if we’re home at the time. Using [Martin’s] solution could extend that alarm’s reach worldwide.

[via Hacked Gadgets]

Wireless Upgrade For A Heathkit HERO 1 Robot

September 9, 2012 by Jeremy Cook 15 Comments

For those of you that don’t know, the Heathkit HERO (Heathkit Educational Robot) was a ‘bot built in the early 1980s. [Rick] wasn’t satisfied with his model ETW-18’s programming interface, so decided to upgrade it to be able to run Python using a hacked wireless router. We’d agree that things have advanced since then, since this little guy was originally programmed in machine code using an onboard keypad. As [Rick] points out, it’s “exactly as awful” as it sounds!

To begin restoring and upgrading his robot, a kit was obtained from [hero-1] to allow for a serial programming interface. Although an improvement, the desire was to be able to program this robot using Python, and to not have to have a cable running across the floor all the time. A router with a serial port was obtained from a thrift store, then hacked using [OpenWrt]. After fitting the components into the robot, [FR3DDY] was born, “A ~30 year old robot, accessible through wifi, capable of running Python.”

Be sure to check out his site, which has some videos we weren’t able to embed. He’s also included some Python code that he used to program it. If this has made you curious about the Python language, why not check out this recent post about learning it the hard way?