Hackaday Links: April 18, 2012

Sandcasting at the beach

[mkb] sent in a video he found of [Max Lamb] sandcasting a stool at a beach in England. The material is pewter, or >90% tin with a little bit copper and antimony thrown in for good measure. While we’re sure there will be a few complaints from environmentalists, it’s still a cool video to see.

Your project needs an OLED display

Here’s a Kickstarter for a tiny 96×16 OLED display. Connect this thing to any I2C bus and you get a 15×2 character display (or a graphic display if that’s your inclination) very easily. Thanks to [Chris] for sending this one in.

Here’s one for a larf

[Ryan Inman] is suing 20 companies because he got mercury poisoning from vacuum tubes. Read that last line again. Most of the companies that sell antique/repro/hard-to-find components like Angela Instruments, Antique Electronic Supply, and even eBay are listed as defendants in the case. This might put at least one company out of business even though they never sold [Ryan] a vacuum tube edit: they did sell him a neon bulb, and courts are generally idiotic when it comes to technological issues. It’s hilarious and sad, so we’ll keep you updated if we get more info.

Nostalgia, the pain from an old wound

The Adafruit blog posted an excellent piece on the Apple ][ game Rocky's Boots, an educational game from 1982 that teaches kids how to connect logic gates. You can play this game in your browser, but we'd like to hear our stories of ancient video games that teach you engineering concepts like The Incredible Machine or Widget Workshop. Leave a note in the comments if we're leaving any out.

A question posed to the community

A company is giving away credit card readers that plug into the headphone jack of an iDevice. [J Smith] writes in to ask us if anyone has gotten one of these and opened them up. Like [J Smith] we’re expecting something a repeat of the CueCat where free hardware is opened up to everybody. If you’ve done a teardown of one of these card readers, send it in.

3DS homebrew

[Mike] sent us a link to [neimod]‘s Flickr photostream. It looks like we’re on the cusp of tearing open the Nintendo 3DS for homebrew apps. Someone who uses this much hot glue must know what they’re doing, right?

Reverse Geocache box looks great and packed with features

[Ranger Bob] crafted this great looking Reverse Geocache box. Our favorite feature is the black piece of acrylic on top. It’s laser cut (not sure if the letters are engraved or not) and gives a great finished look while hiding a couple of things at the same time.

The orange box is a metal cash box, and there’s a smooth indentation in the lid where the handle resides when not being carried. [Bob] removed the handle and mounted the GPS module in that void. But there’s also an OLED display mounted next to it. As you can see in the demo video after the break, the screen is bright enough to be seen clearly through the smoky acrylic covering that depression.

This project gave [Bob] the chance to order his first professionally made circuit board. He did the design in Eagle, managing to keep within the 5cmx5cm limits of Seeed Studio’s least expensive Fusion PCB option. The board hosts the PIC 18F87J50 responsible for handing the screen, GPS module, input button, and USB port. Power comes from an internal Lithium battery.

We’ve featured a lot of Reverse Geocache boxes and they’re still one of our favorite projects because so much love goes into the design and build process. Here’s another one that we chose randomly for your amusement.

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Cheap OLED display for your TI Launchpad

The guys over at the 43oh forums have been working on an OLED display booster pack for the TI Launchpad. The booster pack is now available in the 43oh store and is pretty cheap to boot.

The TI Launchpad is an awesome little dev board with a ravenous fan base. We’ve seen a lot of projects on Hack a Day use a Launchpad – everything from intervalometers to chicken coops. Unfortunately, the MSP430 doesn’t have the market penetration of the ‘board that shall remained unnamed,’ so it’s not very common to see a new Launchpad “shield.”

[bluehash] on the 43oh forums has been hard at work for the past month to put together his OLED booster pack. The display is 128×64 pixels with an incredible amount of brightness that we would expect from an OLED display. The software for the display is based on the SSD1306 driver with two font packs – Courier New large and small. Not a bad little piece of kit for an under appreciated dev board.

Working with the µOLED-128-G1 display

If you’re not already familiar with the 4D Systems µOLED-128-G1 display, [Gary] put together a project that shows some of the features it offers. This is a smart display, having its own onboard microcontroller and a microSD slot. The SD card stores image and video data, while the microcontroller takes care of displaying them based on simple serial commands it receives. This means you can hook it up to a computer or microcontroller and show still or animated sequences with minimal programming effort. We’ve embedded a video after the break, or you can look in on this slot machine project from last year that used the same module.

[Gary] is using a PIC microcontroller programmed with PIC Basic Pro. But most of the work is done with a 4D Systems program called Graphics Composer. You build out the images and animations you want to see on the screen, which are then formatted for the display and written to the SD card. [Gary] mentions that the card is not written using a traditional filesystem, so if you know of another way to write data to and from this card we’d love to hear about it in the comments. The image editing software will also spit out the serial commands necessary to pull your freshly minted graphics up on the display.

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Monitoring the Engine Control Unit

Is there a place in the dashboard of your high performance automobile for this Engine Control Unit feedback panel? There’s several methods of showing information at work here. The row of LEDs at the top of the bezel provide RPM feedback. The two red LEDs with chrome bezels are alarm indicators. But that big OLED display is the centerpiece of the unit. Not only can you scroll through a myriad of display options, but the screen packs more than enough contrast to be readable during the day. It looks like [Mathieu] is selling these units and has decided not to release source code because of this, but there’s a schematic available and a video after the break shows the menu system from which you can draw inspiration.

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OLED displays and small microcontrollers

If you’ve ever thought of utilizing a small and inexpensive OLED display in your project [Rossum] has the details you need to get started. In the past we’ve seen him take a tour of available LCD screens and this is much the same, detailing his look at three different models. In the video after the break each is connected to a driver board that he made. The boards have two important components, the first is a boost driver for the 12-16V input the screens need, the second is an octal buffer necessary if you are using a 5V microcontroller. These take care of the hardware considerations, making it simple to drive them with a chip of your choosing.

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DIY OLEDs

[Jeri Ellsworth] has put together a couple of videos that cover how she made her own organic light emitting diodes, or OLEDs. In the first video, after the break, it discusses the difference between regular, rigid semiconductor LEDs and organic LEDs. The video then goes on to show how to make an OLED as successive layers of materials. Indium tin oxide (ITO) on glass forms a transparent anode. That is then coated with PEDOT:PSS, a conductive polymer mix that is used as a hole transport layer. Then a red diamond ruthenium complex is added to create the emissive layer. The cathode layer is a low work function metal, initially, gallium indium eutectic alloy then later other metals were shown to work. The second video, shows how to juice a glowstick and make OLEDs with the liquid. The dye in blue glowsticks, 9,10-Diphenylanthracene, is an organic semiconductor and will emit light as an electric current is passed through it. The glow stick method seems to have some problems as the ITO coated glass plate is degraded by the glowstick chemicals. It would be interesting to see if using the porous aluminum or similar technique from [Jeri]‘s flexible electroluminescent displays could be used as an electrode.

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