[Pedro] had a busted laptop LCD screen on his hands, but rather than throw it out, he brainstormed what he could possibly do with what would typically be considered a worthless item. He decided to make a simple art installation using the scrapped part, so he gathered a few other supplies and got to work.

The first thing he did was pull the LCD screen from the laptop, separating the front panel from the backlight panel. He drained the liquid crystal fluid from the display, and set it inside a picture frame in place of the glass. He added spacers around the edge of the frame so that the backlight could be mounted several inches behind the LCD panel.

[Pedro] then found a few polystyrene and polycarbonate plastic items from around the house, and placed them inside the frame. As you can see in the picture above, the polarizing filter built into the LCD screen makes for some pretty cool effects.

While you could debate for hours over exactly what is art, there’s no denying that his PolFrame looks cool and is a great way to save electronics from the scrap heap. We just want to know what he did with the LC fluid he drained from the screen!

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.

This swivel arm LCD screen is [Ben Heck's] latest hack. It replaces the hinges that normally only allow one point of rotation on the screen. You can still use the laptop like normal, but when space is at a premium a second adjustment, both in rotation and linear position, has been added using the slots and screw knobs seen above. Ostensibly this is to use on an airplane, where there may not be enough space to fully open your laptop. We’ll let you decide if it’s wise to try to get your own hacks past airport security. Historically, the TSA hasn’t been impressed with hardware hackers. We like how this came out and could see ourselves using these techniques to make a convertible tablet notebook by reworking the cable routing.

We’ve embedded [Ben's] quick demo of the finished product after the break. If you want to see the whole build process it is the subject of Episode 5 of the Ben Heck Show.

[Thanks Geoffrey via Engadget]

[Ben Kurtz] is doing a little WEP cracking but in a bit of a different way than we’re used to. WEP cracking makes us think of war driving; driving around with your laptop open, looking for WiFi access points, and stopping to run some software when you find them. [Ben's] way is similar but different in one key way, he’s using an iPhone as the frontend.

This started as a way to find a use for some leftover equipment. He threw together a Linux box and loaded up Aircrack-ng, the software we often see used in penetration testing. To remove himself from shady-looking activities in public he coded a web interface using the Python package Turbogears. It uses screen, a program often used with SSH to run services concurrently in different terminals, with the option to disconnect without stopping the processes. Now it’s just a matter of parking the hardware near an AP, and doing the work in a browser on your mobile device. You can check out the script he wrote, as well as installation instructions, in his post linked above.

[Thanks Tech B.]

[Note: Banner image not directly related to this post]

When most people encounter dead pixels on an LCD text display, they figure that the display is dead and they decide to scrap it. However when the LCD display on one of [Joe]‘s cordless phones started to show dead rows and columns of pixels, [Joe] decided that he could fix it. With only a pencil eraser, a hot air gun, and a screwdriver (for disassembly), [Joe] was able to fix his phone’s screen in just under 10 minutes. His process involves heating the glue holding the LCD’s ribbon cable to the phones PCB with a hot air gun and using a pencil eraser to reattach segments of the ribbon cable to the PCB. If anyone here has a problem similar to [Joe]‘s, be sure to check out his detailed how-to complete with step-by-step pictures.

There are a ton of digital picture frame tutorials out there. Most are old laptops with crafty case reconfigurations that fit a photo frame profile.

We set out to build a 100% DIY, scratch-built digital picture frame. Our frame has a 12bit color LCD, gigabytes of storage on common, FAT-formatted microSD cards, and you can build it at home. We’ve got the details below.

Concept overview

The bitmap images are stored on common, PC-readable microSD cards. A PIC microcontroller reads the images over a three wire SPI bus. The PIC processes the image data and writes it to a color LCD over a unidirectional, 9bit SPI-like bus. A configuration file on the SD card defines the delay between images.

Hardware

Click for a full size schematic image (PNG). The circuit and PCB are designed using the freeware version of Cadsoft Eagle. All the files for this project are included in the project archive linked at the end of the article.

Microcontroller

We used a Microchip PIC24FJ64GA002 28pin SOIC microcontroller (IC1) in this project. We really like this chip because the peripheral pin select feature lets us put important features on the pins we want; this gives a smaller, simpler, more compact PCB. Each power pin has a 0.1uF bypass capacitor to ground (C1,2). The internal 2.5volt regulator requires a 10uF tantalum capacitor (C12). The chip is programmed through a five pin header, SV1. R1 is a pull-up resistor for the MCLR function on pin 1. Read more about this chip in our PIC24F introduction.

A 32.768kHz crystal (Q1) and two 27pF capacitors (C10,11) provide an oscillator for the real-time clock calendar (RTCC). These parts are optional, the initial firmware doesn’t use them. The RTCC could be used as part of a function that superimposes the current time on the screen. Buttons connected to the programming header could be used to set the time.

SD card

MicroSD cards are completely compatible with regular SD cards, microSD cards can be used in an SD card reader/writer with an adapter. We tested several microSD card holders, and settled on one from SparkFun Electronics. The microSD card requires a bypass capacitor between the power pin and ground (C3). An LED indicates microSD read activity, but its also useful for general debugging (LED1, R2).

Color LCD 128×128 Nokia knock-off

This project is designed around SparkFun’s $20 color LCD panel. The LCD logic runs at 3.3volts and requires a decoupling capacitor (C4). The LED backlight requires a separate 7volt supply, and appears to have an internal current limiter because example designs don’t use external resistors.

The LCD has a separate input for the 3.3volt display supply. Many report noise in the display if this voltage isn’t clean. We used a ferrite bead (L1) and 0.1uF capacitor (C5) to filter the supply, and haven’t experienced any problems. This even worked on a dirty home-etched prototype. The ferrite bead type isn’t important, we used one left over from our tiny web server project.

The small connector is easy to solder on a professional board with a solder mask, but buy several as insurance. SparkFun has a PCB footprint for this part in their Eagle parts library, but the spacing between the pads is smaller than Olimex or BatchPCB will manufacture. We fudged it by decreasing the pad size to get more space between.  Don’t depend on the connector to hold the LCD in place, use tape to hold it down. We used sticky-tack to attach the LCD temporarily.

We prototyped an LCD carrier board prior to sending the final design for manufacture. We recommend against using a ground fill under the connector without a solder mask.

Power supply

A 3.3volt supply, provided by an LD1117S33 (IC2), powers the PIC, microSD card, LCD logic, and LCD display. IC2 requires a 0.1uF bypass capacitor (C6) on the supply side, and a 10uF capacitor (C13) on the output. We used the same tantalum capacitor that we used for the PIC internal regulator.

The LCD backlight is powered by an LM317 adjustable regulator (IC3) configured to 7volts with 240 (R5) and 1100 (R6) ohm resistors. C7 and C8 are 0.1uF bypass capacitors for the LM317.

J1 is a SMD power jack for a common 2.1mm DC barrel plug. C11 is a 10uF electrolytic capacitor that smooths any lag in the supply voltage. C11 has a maximum 16volt input rating, so the supply voltage is best kept under 12volts. 9-12 volts is probably the idea power supply range.

PCB

Click for a full size placement diagram (PNG). L1, C5, and the LCD are on the opposite side. We can’t prototype two-sided boards in mom’s basement, so we sent this design to BatchPCB. Next week we’ll show you how we did it.

Partslist

Firmware

The firmware is written in C using the free demonstration version of the PIC C30 compiler. Learn all about working with this PIC in our introduction to the PIC 24F series. The firmware is included in the project archive at the end of the article.

FAT12/16/32 disk library

Microchip’s FAT 12/16/32 library gives us easy access to files stored on SD cards. We gave a detailed description of this library in our web server on a business card project. If you’re having trouble reading a card with the library, check that it was formatted in a digital camera or using Panasonic’s SD card formatter.

Nokia 6100 LCD driver

SparkFun has a basic 8bit color driver (ZIP) for the Nokia 6100. We ported it to the PIC, and updated it for the 2byte-per-pixel 12bit color mode. With a small amount of added complexity, the pixel write rate could easily be increased by using a different 12bit mode that delivers two pixels using 3 bytes.

The LCD uses a 9bit protocol, one bit more than most SPI hardware will handle. The first bit tells the LCD whether the next 8bits are data or a command. On the PIC 24F it’s impossible to manually bang in the first bit, and then use the SPI peripheral to send the remaining 8bits. We lose direct control of the pins when hardware SPI is enabled. The data entry has to be completely bit-banged, which dramatically reduces the screen refresh rate.

Reading Bitmaps

There are a ton of bitmap formats.  Windows compatibility keeps everyone using the ancient Windows v3 format. We created two C structs to read the V3 bitmap data.

Bitmap files start with a 14byte file header. The first two bytes are the letters ‘BM’, indicating a bitmap.  If the first two bytes are correct, the firmware loads the information header. The last four bytes indicate the beginning of bitmap data, but the current firmware just assumes it will begin at the end of the headers.

A Windows V3 bitmap information header is 40bytes long. The firmware verifies that the header length (offset 14) is 40, indicating a V3 bitmap. If the width (132), height (132), color depth (24), and compression (0) all check out, the image data is processed and output to the screen.

Bitmap images have uncompressed, 1:1 representations of pixel data stored in three byte sequences.  The data starts at the lower right-hand corner of the image; first the red value, then green and blue. Wikipedia has a complete bitmap walk through.

If the color depth of a bitmap image (24bits) is greater than the LCD can display (12bits), we need to discard the least significant bits of color data. To convert from 24bit color to 12bit color, we just chuck half the color data; an 8bit value of 11110011 is pushed four bits to the right, giving 1111.

Firmware walk-through

1. Init PIC, SD, LCD.
2. Read config.ini, create if it does not exist.
3. Use first character of config.ini to set between image delay.
4. Look for images, open next image.
5. Read and check bitmap file header for proper format.
6. Read and check bitmap information header for version, size, color.
7. Read and display each pixel value. Adjust bit depth as needed.
8. Delay, then repeat from 4.

Preparing images

To keep this demo simple, the photo frame only displays the most common bitmap format. Images must be sized to 132x132pixels, with 24bit color.

1. Open a picture with an image editing program.
2. Draw a square selection box over the part of the image you want to use, usually using shift and drag.
3. Crop the image.
4. Size the image to 132x132pixels.
5. Save the image as a windows bitmap, 24bits of color depth.

Other image sizes and formats could be supported with a firmware upgrade (PNG, JPG), especially with a pin-compatible microcontroller upgrade to a giant dsPIC 33F.

Using it

Put images in the root directory of a FAT formatted SD card. Depending on the last device to format the card, it might need to be formatted with a digital camera or the Panasonic SD formatter.

Optional: make a config.ini file with a text editor. Enter a single digit, from 0-9, to set the between picture delay. Save the file. If you don’t create your own config.ini file, one will be created for you with a 1 second delay.

Put the card in the socket, and plug in the digital picture frame. Images will cycle on the screen with the defined delay.

Taking it further

We see a lot of potential in this simple digital picture frame. Many features can be added with a firmware upgrade, some are the basis for future hardware.

• Display other image formats, scale images
• Random fades and wipes
• Display time and date over image, set with buttons connected to programming pins
• Extend the configuration options in config.ini to include longer delays, fade or wipe type
• Use a sub directory for images because there are some file limitations to the root directory of a FAT formatted SD card.
• Add an ethernet connection for networked display updates.

Download: dpf.v1.zip It has moved to here.