Robot Dares You To Snatch The Pebble From This Flower

June 29, 2012 by Mike Szczys 27 Comments

This pleasant-looking plant may try to take your hand off if you’re not careful. The robot flower (translated) includes sensors that cause the petals to move in reaction to external stimuli.

You can just make out the distance sensors as black rectangles on two of the petals. These let the flower track an object by rotating the flower stem. But if they determine the object is getting a bit too close for comfort, the servo motor on the back of each petal will cause the flower to suddenly clamp shut.

The video after the break starts off with an in-depth look at the hardware that went into the project. An Arduino clone called the GRoboduino makes this project a lot easier since it has a bunch of extras on the board aimed at things like sensors and servo motors. The mounting technique for the petal-powering-servos is quite attractive, and we enjoy the Snapple lid (probably not the actual brand but you get the picture) which has been coated with yellow felt for the center of the bloom. The final look is normal enough to fit in with home decor, but it still has enough geek in it to melt our hacker hearts.

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Electric Bike (earplugs Not Included)

June 29, 2012 by Mike Szczys 29 Comments

It’s obvious this bike has some extra parts. But look closely and you’ll see the chainring has no chain connecting to it. Pedaling will get you nowhere since [PJ Allen] rerouted the chain in order to drive this bicycle using an electric motor.

He’s got beefy motor which pulls 350 Watts at 24 Volts. For speed control he opted to use an Arduino, pumping out PWM signals to some MOSFETs. This results in an incredibly noisy setup, as you can hear in the bench test video after the break. But once this is installed on the bike it doesn’t quiet down at all. You can hear the thing a block away.

The original road test fried the first set of 7A MOSFETs when trying to start the motor from a standstill. It sounds like the 40A replacements he chose did the trick through. We didn’t see any information on the battery life, but if he runs out of juice on the other side of town we bet he’ll be wishing he had left the chain connected to the crankset.

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Fighting Over The Frat’s TV Remote

June 29, 2012 by Mike Szczys 11 Comments

[Colin Bookman] lives in a Fraternity house and apparently the remote for the cable box has a way of walking off. He figured out a method to give everyone control of the TV channel in one form or another.

The cable box can be seen perched on that shelf, and [Colin’s] addition is the wooden box sitting on the floor. Inside is an Arduino board, and the cable snaking out of the enclosure is an IR LED. This give the Arduino the ability to send remote control commands to the TV box. The two arcade buttons on the front will switch the channel up or down.

But this is hardly a remote control replacement since you have to get up to use it, so he went a few steps further. The Arduino board was paired with an Ethernet shield. It serves up a web page that has a virtual keypad. So anyone with a smart phone or laptop can log into the server and start changing the channels. We’re not sure if this provides relief from a missing remote, or promotes impromptu fist fights when brothers can’t agree on what to watch. It certainly opens up the possibility of long-distance trolling as you could be sitting in class and decide to change the channel to Lifetime every ten minutes or so.

If you don’t have an Ethernet shield handy we’ve seen a similar setup that uses Bluetooth instead the network.

Turning An Arduino Into A USB Keyboard

June 29, 2012 by Brian Benchoff 23 Comments

The newly released Arduino Leonardo has a few very interesting features, most notably the ability to act as a USB keyboard and mouse thanks to the new ATmega 32U4 microcontroller. This feature isn’t exclusive to the Leonoardo, as [Michael] explains in a build he sent in – the lowly Arduino Uno can also serve as a USB HID keyboard with just a firmware update.

The Arduino Uno (and Mega) communicate to your computer through a separate ATmega8U2 microcontroller. Simply by uploading new firmware with the Arduino Device Firmware Upgrade, it’s easy to have your old Arduino board gain some of the features of newer boards such as the Teensy or Leonardo.

[Michael] goes through the steps required to make this upgrade work and ends his build by showing off an Arduinofied ‘cut, copy and paste’ button project as well as a few multimedia controls. You can check those builds out in the video after the break.

If emulating a USB keyboard isn’t your thing, it’s also possible to install LUFA firmware to emulate everything from joysticks to USB audio devices. Very cool, and very useful.

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Bench Power Supply Resetting Thingy

June 25, 2012 by Jake W 14 Comments

As is common among some hackers, [Henry] re-purposed an ATX power supply unit to function as a bench power supply for testing circuits on a breadboard (much like this fancy example).

However, safety mechanisms on some modern PC PSUs do not automatically reset after over-current protection has kicked in, which soon became annoying for [Henry]. In order to make his power supply more hacker-friendly, he wired up and programmed an ATtiny85V, using some Arduino libraries, to do that for him. This simple project is a great example of using a hack to improve a pre-existing hack.

Printing And Programming A Self-balancer

June 25, 2012 by Mike Szczys 2 Comments

The Hackaday staff isn’t in agreement on 3d printers. Some of us are very enthusiastic, some are indifferent, and some wonder what if they’re as widely useful as the hype makes them sound. But we think [Jason Dorweiler’s] self balancing robot is as strong a case as any that 3d printing should be for everyone!

Don’t get us wrong. We love the robot project just for being a cool self-balancer. Seeing the thing stand on its own (video after the break) using an Arduino with accelerometer and gyroscope sensors is pure win. But whenever we see these we always think of all the mechanical fabrication that goes into it. But look at the thing. It’s just printed parts and some wooden dowels! How easy is that?

Sure, sure, you’ve got to have access to the printer, it needs to be well calibrated, and then you’ve got to make the designs to be printed out. But these hurdles are getting easier to overcome every day. After all, there’s no shortage of people to befriend who want nothing more than to show off their Makerbot/RepRap/etc.

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Using The Raspi As An Ethernet Shield

June 24, 2012 by Brian Benchoff 47 Comments

[Alexandre] wanted to set up a web-based temperature logger with his Arduino, but found the Arduino Ethernet shield a little finicky. Since his Raspberry pi was just delivered, he figured he could use the Raspi as an Ethernet shield with just a little bit of coding.

After [Alexandre] set up his Arduino to send a thermocouple through the USB, the only thing left to do was to add node.js to the Raspi’s Debian installation. Every five minutes, the Arduino wakes up, takes a temperature reading, and sends it over to the Raspberry pi. From there, it’s easy parse the Arduino’s JSON output and serve it up on the web.

In the end, [Alexandre] successfully set up his Raspberry pi as an Ethernet shield to serve a web page displaying the current temperature (don’t F5 that link, btw). One interesting thing we have to point out is the cost of setting up this online temperature logger: the Arduino Ethernet shield sells for $45 USD, while the Raspberry pi is available for $35. Yes, it’s actually less expensive to use a Raspberry pi as an Ethernet shield than the current Arduino offerings. There you have it, just in case you were still on the fence about this whole Raspi thing.