Touchscreen on Raspberry Pi

A friend has a few Elo Touchscreens from a past venture, and I have racked my brain trying to figure out a use for them. After giving up on Android PCs, I took a stab with a Raspberry Pi Model B running the Raspbian image from Noobs.  Two obstacles presented themselves:

1. The Raspberry Pi only outputs HDMI.  For now, I'm going to try an HDMI to VGA converter. Better to get this thing off the ground than hem and haw about a 'better' solution.
2. The touchscreen is inverted.  For this, I installed the xinput-calibrator tool per the instructions on the Raspberry Pi forums given by msmithy12 and a helpful config guide:

sudo apt-get install libx11-dev
sudo apt-get install libxext-dev
sudo apt-get install libxi-dev
sudo apt-get install x11proto-input-dev

download http://github.com/downloads/tias/xinput_calibrator/xinput_calibrator-0.7.5.tar.gz 

tar xvzf (downloaded file)
cd (downloaded file)
./configure
make
sudo make install

Then, from the menu: Preferences/Calibrate Touchscreen

3.  Do not immediately follow the instructions given when you run calibration (place the calibration in a /etc/Xll/...).  Doing so borked my Raspbian install.  Instead, create the file specified in /usr/share/X11/xorg.conf.d/.  I ran "sudo leafpad 99-calibration.conf" to create and edit the file.  After dropping in the calibration indicated, I restarted and found out it stuck.  Woo hoo!

 I will update this space with my progress.  Currently, the setup is:

• Raspberry Pi Model B ($35)
• Elo Touchscreen ET1939L (Pre-owned)
• BYTECC HM-VGA005 HDMI-A to VGA Female Adapter/Converter ($20)
• 1 x WiFi Dongle (Ralink RT5370 chipset) ($10)

Lessons Learned

• Single User Mode could have beenused to save my Raspbian install.  It can be entered by adding init=/bin/sh to cmdline.txt.  I was using Noobs, so holding Shift while the PI boots got me into the editor.
• I like Linux more and more each project.

OFBC: Inspiration and Research

Note: This is part of the Project Write-up for OFBC: One Fluorescent Beer Coaster

The Idea

As night descended at Toxic Barbecue at DEF CON 21, everyone was working through the meat and alcohol they'd consumed much too fast and in much too large a quantity.  Rather than move the party somewhere else (Las Vegas' Sunset Park is safe at night, right?), we began to experiment with cell phone screens, then their flashes.  The lights were bright, but they were also extremely narrow in focus.  

The Liter of Light project gave us an idea to use a liquid to diffuse the light.  As there was still copious amounts of alcohol left behind, we started experimenting.  This 'research' lead us to decide that Smirnoff Ice was the best diffuser.  Filtered beers were awful due to both the dark bottles absorbing light as well as the liquid having no solids to scatter any that was left. Smirnoff had the clear bottle and label as well as a ton of solids from the included fruit juice.  As this was a hacker party and not for frat boys, we had plenty left. The misogynists among us named them 'Bitch Lights' after the colloquial term for Smirnoff Ice: Bitch Drinks.  We had our product; now we needed to separate it from the phones.

Research

DEF CON 22 planning made us realize that we needed to make good on our promises made while too intoxicated to realize we knew nothing about how LEDs actually work.  First stop?  The local Hackerspace, of course.  SYN Shop is in downtown Las Vegas.  Multiple forum members are lighting and electronics techs on The Strip.  They pointed me towards specific packages, drivers and batteries.  I took this foundation and boiled it down to specifics.  I wanted the light to be composed of the following elements:

1. Super Bright LED (1W, 100 lumens)
2. LED driving circuit
3. Battery (3-4 hours of time)
4. Charging circuit (USB)
5. Switch to turn it on
6. 3D Printed Body

Armed with search terms from the forum, I found a wealth of helpful links.  I found LED packages that fit the "Super Bright" definition all over the web.  I learned a ton about batteries and chargers (did you know Sears still exists and has an online store?).  The most helpful site was Instructables.  There, I found several LED driver circuits that I actually understood.  After a trip to Frys left me bewildered with options, I learned to better read datasheets.  Finally, I had a working circuit design.

My Github

https://github.com/RangerDan

And my first project:
https://github.com/RangerDan/rainbow-guess

The work in progress shots from the Misc Electronics post are for this repository.  Need to restore some changes lost after a kernel panic on my raspberry pi dev station and then it is a hop, skip and jump to release.

Warhammer: Age of Reckoning Orc Warboss

Above Miniature Points: 2
Current Point Total: -250

I'm painting this miniature for a friend. It is the Orc Warboss miniature from Warhammer: Age of Reckoning's Collector's Edition. I converted it from it's static pose by standing him atop an Empire Cavalryman that has been unhorsed and stood on. I added the shield shaped like an Orc head, and the scenic base is from cork. Pics as I take them.