Hackaday RBC team finished!

Our Project: “Minotaur’s Revenge”

We built two giant marble mazes. The maze itself is all mechanical, with a 2 person team controlling x and y axis. The fun happens though when you hit buttons to activate magnets and traps on the other team’s table.

Check out the Live Stream. Nothing is happening at the moment, but a couple of dedicated Hackaday fans are checking out an empty couch. We have a very strange readership.

[sonofabit] recorded the last 8 hours of the build at 1fps and made a time lapse video. It’s an hour long, and we thank [sonofabit]‘s CPU for all its hard work. You can also check out the video after the break.

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Reclaiming the numpad for laptop users everywhere

We have to agree with NYCResistor, the exclusion of numeric pads from laptops is a real loss for productivity. Ever try to working with a huge spreadsheet ledger without a 10-key? Sure, there are usually function key alternatives hiding somewhere on those reduced keyboards. But that’s hardly the same thing. We think it’s time to take back the numpad. This project shows you how easy it is by using some old time lab equipment to replace the missing keys.

They’re using a Teensy microcontroller board to translate the key matrix into USB inputs. Most of the work is already done for you because of the USB HID Keyboard library available for the development board. Scanning your own key matrix, or decoding the buttons from some rad hardware like this Walters 600E is up to you. A demo of the rig in action can be found after the jump.

Is there anyone else who wishes the 10-key had an ‘X’ on it for coding hex values? Perhaps that will be a future project for us.

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RC PVC bot

This hunk of PVC pipe is radio controlled. The wheels on the ends provide the locomotion, but it wouldn’t be going anywhere if it weren’t for that little tail strapped to the center of the tube.

When the motors are turning the body of the bot needs something to push against. In this case the tail hits the ground and keeps the chassis from spinning. We have seen attempts to go without a tail by using lopsided wheels to provide angular momentum, but this method is much more reliable.

The control for the bot is scrapped from a toy RC car. Once hooked up to the gearhead motors it’s ready to roll. The real difficulty of the build came in fitting everything into the pipe. A frame was built from a few disks used as mounting platforms which were separated by threaded rod. See it making its way around a gravel road in the clip after the break.

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Defense Against the Dog Arts

It’s possible that it was [Matt Meerian]‘s awesome pun that won us over, not his ultrasonic bicycle dog defense system, but that would be silly. [Matt] wanted an elegant solution to a common problem when riding a bicycle, dogs. While, obscenities, ammonia, water, pepper spray, and others were suggested, they all had cons that just didn’t appeal to [Matt]. He liked the idea of using C02 powered high pressure sound waves to chase the dogs away with, but decided to choose a more electronic approach.  He used a Atmel ATmega644 as the MCU, four 25kHz transmitters, and two 40kHz transmitters. When the rider sees a dog he simply flips a switch and it activates the transducers (along with, cleverly, a human audible horn so he doesn’t have to look down to know it’s working). So far [Matt] has not had a dog chase him in order to test it’s efficacy, but his cat clearly seems unaffected by the device as you can see after the break. Continue reading “Defense Against the Dog Arts”

From 0 to C: teaching programming without a computer

It’s no secret that learning how to program is very hard, and teaching it doubly so, requiring the student to wrap their head around very unorthodox concepts. [Ubi de Feo] over at the Amsterdam tech collective Hello, Savants! has a unique solution for taking someone who knows nothing of programming and turning them into a computer aficionado capable of deftly wielding semicolons and parens. It’s called From 0 to C, and aims to teach students programming in an environment without computers.

For his class, [Ubi] made up a lot of wooden boxes with eight subdivisions representing the bits in a byte. By putting ping-pong balls in each slot, [Ubi]‘s students can grasp the concept of counting by powers of two and quickly move on to hexidecimal and more advanced concepts like bit shifting.

After learning the ins and outs of how stupid computers actually are, [Ubi]‘s students then learn the syntax of a language of their choice (C, JavaScript, or Python, for example), and write a few programs.

Although we’re sure most of our readers are far past the ‘learning programming from a blank slate’ portion of their hacker and maker career, anything that gets more people solving their own problems is okay in our book. [Ubi] has a pretty neat take on the pedagogy of teaching programming, and we’d really like to see his work expand outside his Amsterdam collective.

Comparing Altium and Cadence PCB layout tools

We see a lot of projects using Eagle for the schematics and PCB layout. There are a few that use Kicad, but we hear very little about other alternatives. Recently, [Limpkin] has been working with Altium and Cadence and wrote about how they compare when it comes to PCB layout. Neither are free packages so it’s good to know what you’re getting into before taking the plunge.

[Limpkin] begins his overview by mentioning that the schematic editors are comparable; the differences start to show themselves in the PCB layout tools. Here you can see that Altium always labels the pads so you know what net each of them belongs to. Cadence (whose PCB layout tool is called Allegro) will display the net if you hover over the pad with your mouse. Both have 3D rendering, with Altium’s looking a bit more pleasant but what real use is it anyway? Okay, we will admit we love a good photorealistic board rendering, but we digress. The most interesting differences show themselves once traces are all on the board and need to be rejiggered. Cadence will actually move traces on other layers automatically to avoid collision with a via that is late to the party, and Altium shows some strange behavior when dragging traces. [Limpkin] doesn’t register a final judgement, but the comparison alone is worth the read.

Flip-dot display is an advertising experience we can get behind

This huge and mesmerizing interactive display is just a big piece of advertising. It is a flip-dot display. Each pixel is a mechanical disk, white on one side and black on the other. The team over at BreakfastNY hacked the display modules and wrote their own software so that it can be refreshed with lighting quickness. To the left you can see the high contrast text, but on the right it’s showing the camera-based interactivity. A few seconds later this gentleman sweeps his arm to the side and all the pixels scatter as if blown away by a forceful wind. You might as well just skip down to the video after the break right now.

The display is an advertisement for a new show on the TNT network called Perception. We’ve got to say, if you’re going to advertise this is the way to do it. Make something cool, then share the details. We get to enjoy the clickity-clack of all those dots flipping into place and they got us to at least recognize the network and say the name of the show. Everyone wins.

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