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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[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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In-button display for your car’s dashboard

OLED display in a dashboard button

Here’s an interesting take on augmenting a car’s dashboard. [Daniel] is using a button blank to house a 1″ OLED display in his Jetta. It shows auxiliary data such as boost pressure and several sets of temperature readings. The display itself has a tiny little circuit board with a PIC 24 to drive it. A larger board, seen above, collects the temperature data from some sensors that [Daniel] added as part of the hack. There are some pictures of the installed display inside of the dark car and it looks really easy to read. It also sounds like there’s some dimming functionality built into the firmware. This is the easiest way we’ve seen to add a display to your dashboard as it just requires you to pop out a button blank, rather than disassembling the entire console or patching into what’s already there.

Todays Arduino Moment

We have gotten a number of Arduino tips in the last couple days, and we thought we would combine them for your convenience. The first tip we received was for some hints provided by [Bill] on some digitalWrite() alternatives. Similar to some previous research we covered, this tip also includes some tips on how to make the direct register writing a little easier by using #define to simplify things. Obviously this wont be as idiot-proof as digitalWrite() is, but we think you can handle it.

Our second tip is for a set of OLED displays from 4dsystems sold as Arduino Shields. They have a couple of different sizes from .96″ to 1.7″, depending on your needs and budget. There is no official display library for them yet, but 4dsystems have been kind enough to provide a few resources to work from. Hopefully we’ll see a few great applications from this, maybe a much bigger pixel Mario? A much smaller Game of Life? Feel free to send us your projects, or leave your ideas in the comments!

OLED hack saves juice on Nexus One

Want to really stretch the battery life on your phone? If you have an OLED display [Jeff Sharkey] may have the answer. He did some testing with his Nexus One to see if color alterations can save on current. Darker colors draw less amperage and he found that the red pixels are the most efficient. He did a little work with SurfaceFlinger, which handles the display on Android devices to make this easy, but what will you get by going red? He measured that using only the red pixels dropped the current use down to 35% of what the full color display was pulling. This reminds us of those efforts to save energy by running a black background with Google. Whether you use it or not his post is an interesting read.