Working with very cool LCD modules from Sharp


Here’s some interesting hardware for you: Sharp came out with a very cool series of LCD displays, gong by the name Sharp Memory LCD. Not only are these displays very low power – on the order of about 5 microAmps to keep the display alive – but some of the smaller displays are reflective, making them eminently readable even in daylight. [Mike] decided he’d take a look at these displays and liked what he found.

While these displays are still pretty new, there are a few breakout boards available to make them accessible to desktop tinkerers. The folks at MakerDyne have a breakout board available and there’s one by kuzyatech over on Tindie.

While these displays are readable in daylight and are extremely low power, don’t expect to display LCD video on them anytime soon. The refresh rate is still fairly slow, but you might be able to get away with simple animations with interlacing and so forth. Still, outside of eink, you’re not going to find a better display in terms of power consumption and daylight readability.

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Tiny MAME cabinet built from Raspberry Pi

It’s been a while since we’ve seen [Sprite_tm] pull a project from thin air, and we haven’t seen him do anything with a Raspberry Pi yet. All things must pass, and finally [Sprite] has unleashed his tiny, pocket-sized MAME machine to the world.

The build uses a Raspi for all the Linux-ey and MAME goodness, but [Sprite_tm] didn’t want to fiddle around with the HDMI or analog video output. Instead, he chose to use an SPI-controlled TFT display that is only 2.4 inches across. This isn’t a new hack for [Sprite] – he figured out how to connect this display over GPIO pins with a Carambola earlier this year.

To make his cabinet portable, [Sprite] opted for using old cell phone batteries with a cleverly designed charging circuit. When the power supply is connected to +5V, the batteries charge. When this power is removed, an ATtiny85 provides 5V of power to the Raspi and display.

No arcade cabinet is complete without a marquee of some sort, so [Sprite] used an extremely tiny 128×32 white OLED to display the logo of the game currently being played. Everything in the Raspi is set up to be completely seamless when switching between games, automatically configuring the controls and marquee for the currently selected game.

You  can check out [Sprite]‘s mini MAME booting straight into Bubble Bobble after the break along with some gameplay footage and finally switching it over to Nemesis. A very awesome build from an exceedingly awesome maker.

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An Adafruit Raspberry Pi extravaganza

The folks at Adafruit are busy as a bee working on bringing some of their really cool boards to the Raspberry Pi platform. Here’s a few that came in over the last few days:

16 servos is almost too many

Servos require a PWM output but the Raspi only has hardware support for PWM on a single GPIO pin; certainly not enough to build a gigantic, city-leveling robot. [Kevin] over at Adafruit put together a tutorial for using this 16 channel servo driver with the Raspi.

12 bit DAC

With only one PWM pin and no analog out, it was only a matter of time before someone hooked up the Adafruit 12 bit DAC to the Raspberry Pi.

16×2 LCD displays

Both the servo and DAC builds use the Adafruit I2C library and a bit of Python. Of course it’s possible to treat the GPIO pins on the Raspberry Pi as digital outs, just as [Mikey] did with his Raspi LCD display tutorial.

So, what distro are you using?

Of course all these builds use Adafruit’s Occidentalis distro, a maker-friendly Linux distro we’ve posted about before. It’s too useful to languish as a single Hackaday post, so here it is again.

Digital zoetrope uses 18 LCD displays

[Jasper] sent in a project he, [Quinten], and [Mr. Stock] have been working on for a while. It’s called the Pristitrope and brings the classic 19th centrury paper-based animation device into the 21st century with 18 LCD displays.

The lazy suzan portion of the build was fabricated out of plywood cut on a CNC router and fastened together with the help of a slip ring to transfer power between the stationary and spinning portions of the device. For the electronic part of the build, eighteen LCD displays were connected together on a data bus with each display independently addressable by a microcontroller.

One really interesting feature of the Pristitrope is its ability to detect if it is currently rotating clockwise or counterclockwise. While [Quinten]‘s video doesn’t show off the full possibilities of this feature, the spin sensor makes it possible to always have an animation played in the right direction regardless of how the Pristitrope is spun.

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Reverse engineering a Nokia LCD

LCD displays taken from old Nokia phones have been a staple of the hardware makers for years now, so we’re very happy to see [Andy] reverse engineering a full color QVGA display so we can move our grayscale projects over to a full-color display.

The screen in a Nokia 2730, 5000, and 7100 cell phone is a wonder of technology – its 18-bit color with a very high-resolution piqued [Andy]‘s interest. He bought a second-hand Nokia 2730 off of eBay and started taking it apart. After checking out the schematics for the phone, [Andy] had a few breakout boards made; especially useful since he found a few connectors as well.

With a great deal of Googling, [Andy] found another lost soul who successfully broke into a similar LCD display and discovered it was command-compatible with a Magnachip LCD controller. The only way forward was to send a few of these commands over to the display and watch what happens.

[Andy] managed get pixels drawn on the screen, and found a few interesting features: hardware scrolling is enabled, as is changing between portrait or landscape orientations. From a second-hand phone on eBay, [Andy] now has a very nice QVGA display. We’re calling this a win, but you can judge the video after the break for yourself.

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Putting laptop LCDs to use with an FPGA

We’re always impressed with the number of laptop displays we’re able to pick out of the trash. Most of the time the computer is borked beyond repair so we end up with a lot of functional but unusable LCD panels. As a service to us all, [EiNSTeiN_] figured out how to control an LCD panel using a cheap homebrew FPGA board.

LCD panels don’t use a simple protocol like VGA for turning pixels on and off. Instead, the very high-speed LVDS is used. LVDS is beyond the capabilities of simple microprocessors, so [EiNSTeiN_] built himself a clone of an XuLA FPGA prototyping board and set to work. After figuring out the signal lines to the panel, [EiNSTeiN_] pored over the timing diagrams for the LVDS controller and the LCD panel. From the data sheets, he figured out data is usually sent to the panel at about 500 MHz. The homebrew FPGA board couldn’t manage that speed so [EiNSTeiN_] cut the FPGA clock in half.

While LCD’s 60 fps refresh rate was reduced to 30 fps, [EiNSTeiN_] says there’s only a little flicker. Not bad for something that could have easily been trashed.