Oscar Updates Your Grocery List From The Trash

November 23, 2013 by 26 Comments

grocerylist

[Dan] has come up with a novel solution to the age old problem of keeping your grocery list up to date. He’s added a bar code scanner and a Raspberry Pi under a kitchen cabinet. He calls the system “Oscar”, though we don’t see any grouchiness in his trash can. When [Dan] runs out of a product, he simply throws it away. Just above his garbage and recycling bin is a low cost barcode scanner. [Dan] holds the item until the scanner reads, then sends it on it’s way to recycling or the landfill. The decoded bar code is processed by a Raspberry Pi also hiding under the cabinet. The Raspberry Pi sends the data to Trello.comusing the Trello api.

If a product isn’t recognized by Trello’s database, trello dispatches a text message to [Dan’s] phone. He can then add the product information via a web interface. We think the user interface is what’s great here. Once products are in the database, the only thing that has to be done day to day is pause for a moment before throwing a package away. [Dan] has all his code up on github, and has also created a reddit thread for Oscar.

http://www.youtube.com/watch?v=9_MNOOgFDg4

[via reddit.com]

Raspi Mini Laser Engraver

November 23, 2013 by 9 Comments

If you’ve got a lot of spare parts lying around, you may be able to cobble together your own laser engraver without too much trouble. We’ve already seen small engraver builds that use an Arduino, but [Jeremy] tipped us off to [Xiang Zhai’s] version, which provides an in-depth guide to building one with a Raspberry Pi.

[Xiang] began by opening up two spare DVD writeable drives, salvaging not only their laser diodes but the stepper motors and their accompanying hardware, as well as a handful of small magnets near each diode. To assemble the laser, he sourced an inexpensive laser diode module from eBay and used a vise to push the diode into the head of the housing. With the laser snugly in place and the appropriate connecting wires soldered on, [Xiang] whipped up a laser driver circuit, which the Raspi will later control. [Xiang] worked out the stepper motors’ configuration by following [Groover’s] engraver build-(we featured it a few years back)-attaching the plate that holds the material to be engraved onto one axis and the laser assembly to the other.

Check out [Xiang’s] project blog for details explaining the h-bridge circuits as well as the Python code for the Raspi. As always, if you’re attempting any build involving a laser, please use all necessary precautions! And if you need more information on using DVD burners for their diodes, check out this hack from earlier in the summer

Solder Sucker Meets Industrial Vacuum Pump

November 22, 2013 by 19 Comments

[borgartank] is starting a hackerspace with a few guys, and being the resident electronics guru, the task of setting up a half-decent electronics lab fell on his shoulders. They already have a few soldering stations, but [borgar] is addicted to the awesome vacuum desolderers he has at his job. Luckily, [bogar]’s employer is keen to donate one of these vacuum desolderers, a very old model that has been sitting in a junk pile since before he arrived. The pump was shot, but no matter; it’s nothing a few modifications can’t fix.

The vacuum pump in the old desoldering station was completely broken, and word around the workplace is the old unit didn’t work quite well when it was new. After finding a 350 Watt vacuum pump – again, in the company junk pile – [bogar] hooked it up to the old soldering station. Everything worked like a charm.

After bolting the new and outrageously large pump to the back of the desoldering station, [bogar] wired up a relay to turn on the pump with the station’s 24V line. Everything worked as planned, netting the new hackerspace a 18 kg soldering station.

DIY Filament: The Filabot Wee

November 22, 2013 by 24 Comments

filabotwee

Now there’s yet another option for making your own 3D printer filament: the Filabot Wee. It looks like their once open source model that they pulled from Thinigiverse earlier this year has received a significant makeover, though we aren’t sure what parts may have changed. (EDIT: Filabot says the Wee is still open source, and that once they’ve updated the files they will be available again.)

As you would expect, the Wee has a PID temperature controller and is capable of extruding both ABS and PLA pellets into either 1.75mm or 3mm-diameter filament. Speed varies depending on materials and thickness, but can reach 5 to 20 inches per minute of filament extrusion. Though the Filabot gang is selling the extruder as a kit, you can probably save a few bucks if you have access to a laser cutter and some other basic materials.

You should expect to spend more for Filabot parts ($649) than you would for the original Lyman extruder, though perhaps a more fair comparison would be the new third version of the Lyman extruder, whose bill of materials approaches $900. Considering Lyman’s recent comments that indicate an extrusion rate of 40-50 inches per minute, the extra bucks may be worth it. You can check out a demonstration video of the Filabot Wee after the break.

Continue reading “DIY Filament: The Filabot Wee” →

Hack Your Stove In The Name Of Homebrewing

November 22, 2013 by 10 Comments

stovehack

[Tim] is a homebrewer. Temperature profiling during the mashing process is apparently even more critical than the temperature curve of a solder reflow oven. His stove just wasn’t giving him the level of control he needed, so [Tim] added a PID temperature controller to his stove. Electric stoves generally use an “infinite switch” to control their burners. Infinite switches are little more than a resistor and a bimetallic strip in a single package. Not very good for accurate temperature control. The tricky part of this hack was to make it reversible and to have little visual impact on the stove. A stove top with wires hanging out would not only be dangerous electrically, it would also create a hazardous situation between [Tim] and his wife.

[Tim’s] brewpot only fit on the stove’s largest burner, so that was the only one that needed PID control. To keep things simple, he kept the commercial PID controller outside the stove’s enclosure. Inside the stove, [Tim] added a solid state relay. The relay is mounted to a metal plate, which screws to the back of the stove. The relay control lines run to an audio jack on the left side of the stove. Everything can be bypassed with a switch hidden on the right side of the stove. In normal operation, the switch is in “bypass” mode, and the stove works as it always has. When mashing time comes along, [Tim] flips the switch and plugs the jack into his PID controller. The temperature sensor goes into the brewpot itself, so no stove modification was needed there.

The end result is a very clean install that both [Tim] and his wife can enjoy.  Save a few bottles for us, [Tim]!

If You Own A Camera You Need To Try Light Graffiti

November 22, 2013 by 24 Comments

Do you have a camera that’s capable of controlling how long of an exposure it takes?  With this and any small light source, you can make a really awesome illuminated image like the one featured above.  Combine this with the hacking skills that you’ve hopefully learned from reading Hackaday, and the visual possibilities are endless.

Let’s look at the background of this entertaining light hacking technique, and how you can make images like this yourself!

Continue reading “If You Own A Camera You Need To Try Light Graffiti” →

Learn Engineering And Draw Narwhals

November 22, 2013 by 23 Comments

narwhals

Using LEGO robots and other ‘intro to robotics’ platforms is a great introduction to kinematics and programming, but if you’re teaching a classroom of people who don’t know what a 1/4-20 screw is, perhaps it’s not the right introduction to engineering. That’s the thinking behind NarwhalEdu’s upcoming, Kickstarted online course: give kids a bunch of servos, bolts, and a microcontroller, and they’ll be able to build anything, and not just what the instructions for a Mindstorm’s robot says.

Robots, Drawing, and Engineering is an online course built around a simple SCARA arm robot. It’s made out of laser cut hardboard and powered by three servos and an Arduino Nano with an extension shield. After building this robot in the first hour of the online class, students then learn a little programming and get their robot drawing everything from narwhals to nyan cats and faces.

In the second part of the course, students then tear apart their robot kit and start making other, cooler interesting devices. There’s a contest for the coolest project that will hopefully go a long way to show how creative engineering can be.

Two videos below of the NarwhalEdu SCARA arm in action.

Continue reading “Learn Engineering And Draw Narwhals” →