Hackaday Links: Sunday, April 21st, 2013

hackaday-links-chain

Regular reader and master hacker [Bill Porter] got married. Congratulations [Bill] and [Mara]! The two of them just couldn’t leave their soldering irons at home. The actually swore their vows by soldering together a circuit during the ceremony (blinky wedding dress, el wire tuxedo, and all).

[Kevin] sent in a link to [Red Fathom's] hacked Wacom tablet. It’s the screen from a Wacom-enabled laptop brought back to life with a Teensy and an LVDS interface module.

The Neato XV-11 is able to find its charging station when the batteries run low. [Derek] figured out that you can make a second station using some reflective tape.

If you use your drill a lot you’ll eventually break the rubber thing that holds the key to the chuck. Here’s a way to 3D print a replacement.

[Torxe] put eight floppy drives to use as a polyphonic Arduino-controlled MIDI player. And while we’re on the subject of Arduino controlled projects you should take a look at this web-interface to tell you if the foosball table is being used.

And finally [Th3 Bad Wolf] sent in this link to a milling machine built out of LEGO. It is able to mill floral foam and uses a lathe-like setup for one of the table axes.

LVDS on an FPGA could make it possible to reuse laptops LCDs and the like

Search around the Internet and you’ll find a landfill of forum threads asking how to drive the LCD screen from a dead laptop. The answer is always that there is just no way to do it. That’s because most of them use a Low-Voltage Differential Signalling protocol that just isn’t available through the hardware used in hobby projects. But the appearance of this board could signal that things are about to change. We don’t want to get your hopes up too much. This isn’t an open source project, but it is a piece of hardware that can make LVDS available for the 8, 16, and 32-bit microcontrollers you’re used to working with.

It’s a derivative of a project [Thomas Jespersen] worked on for a customer. It uses an FPGA to implement the LVDS standard used by high-pixel-count LCD displays. It contains enough memory for a full frame-buffer, and includes a Motorola-8080 communication standard. [Thomas] gives a full description of how the setup works in the video after the break. Demonstrations start about 7:30 into the video with an STM32 F4 Discovery board driving the display.

[Read more...]

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.

Laptop LCD reused in Beagleboard project

This daughterboard lets [Matt Evans] drive a laptop LCD using a Beagleboard. Apparently the Beagleboard gained a VGA header when it moved to revision C but [Matt's] working with revision B4 which is why he had to do all of that ninja soldering with the blue wires. The driver board itself is a thing of beauty, hosting a DS90C363 LVDS serialiser as well as some buffer chips that handle level conversion for it. He’s also included an ATmega48 so that he has some options for future improvements.

The LCD is mounted in a custom acrylic case, with Beagleboard and driver board taped to the back of it. There’s RS232 and a USB hub which opens up the possibility of using a WiFi dongle for communications. So far he doesn’t have much functionality other than displaying images on the screen but there is some talk about using a touchpad for control. We’d love to see a touchscreen overlay, transforming the build into a proper ARM-based tablet.