Throughout the 1960s, the management at RCA thought LCD
displays were too difficult to commercialize and sent their engineers and researchers involved in LCDs off into the hinterlands. After watching [Ben Krasnow]’s efforts to build a liquid crystal display, we can easily see why the suits thought what they did. It’s an amazing engineering feat.
Before building his own version of an LCD (seen above in action), he goes through the mechanics of how LCDs operate. Light enters the display, goes through a polarizer, and is twisted by a liquid crystal material. The first successful LCDs used two types of liquid crystals – chiral and nematic. By combining these two types of molecules in the right proportion, the display can ‘twist’ the polarized light exactly 90 degrees so it is blocked by the second piece of polarizing film in the display.
Besides getting the right crystals and engineering processes, another major hurdle for the development of LCDs
displays is transparent electrically conductive traces. [Ben], along with every other LCD manufacturer, uses a thin layer of indium tin oxide, or ITO. By embedding these clear electrodes in the display, segments can be built up, like the seven segment displays of a calculator or a bunch of tiny dots as found in a TV or computer monitor.
In the end, [Ben] was able to build an extremely simple single-segment LCD
display out of a pair of microscope slides. It does modulate light, just barely. With a lot of work it could be made in to a calculator type display but for now it’s an awesome demonstration of how LCDs actually work. Continue reading “Crafting A Liquid Crystal Display”
In our opinion, reverse engineering may be one of the best ways to tease your brain. [Andy] just did that by reverse engineering the Sony Ericsson Vivaz high resolution LCD (cached copy here). In his (very) nicely written article, [Andy] explains all the steps that led him to the result shown in the picture above. He started by finding the repair manual of the Vivaz, to discover that the display could be interfaced with 8080 type parallel signals. That meant that he could use a standard microcontroller without high speed buses to interface with it, in this case the STM32F4. Next in his adventure, [Andy] ordered the appropriate connector and took a more educated guess for the onboard microcontroller. A long Google search brought up the R61523 from Renesas. So he designed his breakout board, got it produced and a few hours later a nice picture was being shown on the LCD. He even took the time to compare the original display with the clone he found on the webs, and modified his graphics library to support this display.
Security researcher [Fran Brown] sent us this tip about his Tastic RFID Thief, which can stealthily snag the information off an RFID card at long range. If you’ve worked with passive RFID before, you know that most readers only work within inches of the card. In [Fran’s] DEFCON talk this summer he calls it the “ass-grabbing method” of trying to get a hidden antenna close enough to a target’s wallet.
His solution takes an off-the-shelf high-powered reader, (such as the HID MaxiProx 5375), and makes it amazingly portable by embedding 12 AA batteries and a custom PCB using an Arduino Nano to interpret the reader’s output. When the reader sees a nearby card, the information is parsed through the Nano and the data is both sent to an LCD screen and stored to a .txt file on a removable microSD card for later retrieval.
There are two short videos after the break: a demonstration of the Tastic RFID Thief and a quick look at its guts. If you’re considering reproducing this tool and you’re picking your jaw off the floor over the price of the reader, you can always try building your own…
Continue reading “RFID Reader Snoops Cards from 3 Feet Away”
[Art] has done some amazing work with character LCDs. He started with a classic character LCD. These LCDs are typically controlled by Hitachi HD447XXX compatible controllers. Hitachi’s controllers allow several custom characters to be defined. We’ve used those characters in the past for applications like spinners and bar graphs. [Art] took things to a whole new level. He created a double buffered LCD graphics library which allows these old LCDs to perform tricks usually reserved for graphical LCDs. Even more impressive is the fact the whole thing runs on a Microchip PIC16F628A programmed mostly in PICBASIC.
According to [Art’s] thread on the PICBASIC forum, he is using the custom character memory as a framebuffer. The LCD is set to display all 8 custom characters. Each frame is then in the PIC’s RAM. The completed frames are then pushed to the custom character memory of the Hitachi LCD controller. The result is a very smooth update rate on the LCD. [Art] wrapped the whole example up in a video reminiscent of the C64 demoscene.
Continue reading “Teach an Old LCD New Tricks”
As the creator of the Gameduino, a shield that adds a VGA port and graphics capability to any Arduino, [James] knows a little something about generating high quality video with a microcontroller. His latest project, the Gameduino 2, blows his previous projects out of the water. He’s created an Arduino shield with a built-in touchscreen that has the same graphics performance as the Quake box you had in the late 1990s.
The power behind this shield comes from a single-chip graphics solution called the FTDI EVE. This isn’t the first time we’ve heard about the FTDI EVE, but this is the first instance of a project or product using this very cool embedded graphics engine. The Gameduino 2 uses an FT800 graphics chip over an SPI connection to give a 480×272 TFT touch panel the same graphical capabilities as a Voodoo 2 graphics card. From the video, [James] is able to put thousands of sprites on a screen, as well as simple 3D animation, and extremely impressive 2D animations using only an Arduino.
While the Gameduino 2 is designed to be a game console you program yourself, we’re thinking this would be even more useful as a display for standalone projects.
The old Fluke 8050a multimeter from the 80s is an awesome piece of lab equipment. It’s built like a tank, and thanks to the newer more portable models, this old meter is available for a pittance on eBay. [Ken] picked up a few of these meters and decided to give one of them a little upgrade – a 2.2″ 320×240 LCD display that is a vast improvement on the old stock seven-segment numerical display.
Inside the Fluke 8050a is a 40-pin DIP processor that handles all the computations inside the unit. [Ken]’s solution to tap into this processor was to take a 40-pin PIC microcontroller, bend some of the pins backwards, and use the remaining pins to drive the new LCD display. It’s actually somewhat brilliant in its simplicity and looks really cool to boot.
The rest of the circuitry consists of a level converter and a few wires going directly to the LCD display. [Ken] already has another Fluke 8050a on the bench waiting for a facelift and some plans for a few improvements that include a bar graph, histogram, and possibly even a touch display.
[Ibrahim] picked this little LCD module out because of its price point and resolution. In single units you can grab one of the 128×32 pixel displays for just $11. The only problem is that the pinout is too small to use with a breadboard. He whipped up a breakout board for it that throws in some extras.
First off, we like it that the board doesn’t add much to the part’s outline. What it does add is a Low-DropOut voltage regulator and a level converter. The upper range of the LCD’s input voltage is 3.3V, and these added parts make it possible to drive the device using 5V hardware like the Arduino Uno pictured above. While he was adding in parts he included a MOSFET to switch the backlight. This way he can use PWM for dimming as well.
We usually hit eBay when looking for LCD screens. A search for the NHD-C12832 part number didn’t turn it up. We tried out FindChips for the first time (owned by Supply Frame who just bought Hackaday) and it works just as well as Octopart which we’re more familiar with since we’ve seen some hacking of that site before.