Learning Letters, Particularly R, F, I, & D

June 10, 2013 by Brian Benchoff 12 Comments

8993376562_55ff3846b3

After [yohanes] picked up a toy at a yard sale – a Leap Frog Letter Factory Phonics – he thought he could do better. The toy originally asked a child to find a letter, and after digging one of 26 plastic characters out of a plastic tub and placing them on the Letter Factory’s sensor, would play a short musical ditty. [yohanes]’ version does the same, but because he made it himself it is infinitely more expandable.

The letters for [yohanes]’ version are RFID tagged. This, combined with a cheap RFID module and a bluetooth module means a Raspberry Pi can read RFID cards from across the room. From there, it’s a simple matter of writing up some Python to ask his toddler for a letter, reading the bits coming from a bluetooth, and keeping score.

The build isn’t over by a long shot. [yohanes] still needs to make his build multilingual by adding Indonesian and Thai. There’s also a possibility of adding a spelling game to make it more interesting.

Hackaday Links: Sunday, June 9th, 2013

June 9, 2013 by Mike Szczys 25 Comments

This week we saw an interesting animated motorcycle tail light over on Reddit. But there wasn’t really enough background to get its own feature.

The NeuroKnitting project captures brainwaves by weaving them into a scarf.

On Semiconductor is showing off an 8x8x8 LED cube which they claim as 12,000 LEDs. We can’t figure out where all those LEDs are used in the design, but maybe you can. Here’s one that we know has 4096 LEDs in its matrix.

[Jeff] used hard drive platters as the disc section of his original Enterprise desk model.

Play around with an SNES controller and Arduino by following [Damon’s] guide.

Hackaday Alum [Jeremy Cook] posted an update of his laser graffiti project. His earlier effort used camera tricks to capture the image but this time around he’s exciting phosphorescent glow material to make a persistent display visible to the human eye.

This server hides in plain sight after being wrapped in a hard cover book binding. Hopefully this won’t cause heat dissipation problems.

[Trumpkin] built his own Nixie tube wristwatch which we think has the potential to be as neat as the one [Woz] wears.

Super-cap Powered Blinky Jewelry Charged By The Sun Or USB

June 9, 2013 by Mike Szczys 16 Comments

blinky-jewelry-solar-supercap

We don’t see ourselves wearing these pendants around, but we still enjoyed taking a look at the design. These are just two from a wide range of offerings meant to be worn around and recharged by the sun. But a cloudy day won’t ruing the fun; they can be topped off via USB as well. Parts lists and schematics are included in the assembly Instructables for both the Owl and the Heart.

[Marty] and [Robin], a brother and sister developement/design team, were showing them off at the Sector67 hackerspace in Madison, WI. The single integrated circuit used in both is an OpAmp responsible for managing the blinking. The heart board has a calculator-style solar cell which charges that 0.5F supercap. The Owl has just a 0.022F coin-type capacitor and features a different style of solar harvester. The six components around the cap are each individual solar cells. [Marty] told us that they pump out a ton of juice in direct sunlight, outperforming the calculator-style cell. The opposite is true indoors. But as we’ve seen before, indoor solar harvesting is a tough game.

Need even more bling around your neck? Check out these LED matrix pendants.

Open Source PLC

June 9, 2013 by Brian Benchoff 60 Comments

In industrial applications, controlling relays, servos, solenoids, and the like isn’t just a matter of wiring in an Arduino and plugging in some code. No, for reliable operation you’ll need a PLC – a programmable logic controller – to automate all your hardware. PLCs are usually pretty expensive pieces of hardware, which led [Warwick] to come up with his own. He built two versions, one large and one small that can handle just about any task thrown at them.

Both devices are powered by an ATMEL SAM7S ARM chip running at 48 MHz. The smaller of the two devices has 10 digital inputs, 4 analog inputs, and 8 digital outputs able to sink 200 mA each. The larger PLC has 22 digital ins, 6 analog ins, and 16 digital outputs. Both of these devices have a ton of connectivity with USB, RS-232 and RS-485 ports

Below you can see the large PLC being used as a barcode scanner and as a strange device using compressed air to levitate a ping-pong ball. There’s also a demo of the smaller PLC lighting up some LEDs.

Continue reading “Open Source PLC” →

This Week On HANDMADE.hackaday

June 9, 2013 by Caleb Kraft 7 Comments

This week on HANDMADE.hackaday we’ve seen a pretty good variety of skills.

HANDMADE.hackaday.com is growing quickly. Keep sending in those good tips! We have some videos of our own planned as well, keep an eye out for those!

1,200 Hours Of Work Results In The Smallest V12 Engine

June 9, 2013 by Caleb Kraft 41 Comments

[José Manuel Hermo Barreiro] has spent many many hours crafting these tiny engines from hand. Every single piece is custom made specifically for the engine it is going onto. He has created aircraft engines, car engines, and marine engines that all actually run and are the smallest of their kind in the world.

At one point in this video he stands in a room with several engines lined up, all running smoothly and considers that there are possibly over 15,000 hours of work right there in front of him.

Here’s a video specifically about the 12 cylinder construction.

[Thanks Staskazz]

Echolocation Pinpoints Where A Gunshot Came From

June 9, 2013 by Mike Szczys 50 Comments

echolocating-gunshots

[Kripthor] suspected that hunters were getting too near his house. When thinking of a way to quantify this belief he set out to build a triangulation system based on the sound of gunshots. The theory behind it is acoustic location, which is a specialized type echolocation.

The most common example of echolocation is in Bats, who emit ultrasonic noise and listen for its return (echo) to judge the location of objects. [Kripthor] doesn’t need to generate the sound himself, he just needs to pick it up at different points. The time difference from the three samples can be used to triangulate coordinates as seen in the image above.

He first tried using a PC sound card to collect the samples. The stereo input only provides two channels so he tinkered around with a 555-based multiplexing circuit to sample from three. The circuit noise created was just too great so he transitioned to using an Arduino. The ADC samples from each microphone via an NPN transistor which is used as a simple amplifier.

This brings to mind a homebrew sonar hack from way back.