Better Remote Desktop Resolutions on Linux

Did you know you can remote desktop into a linux machine and have the remote desktop resolution be much larger than the physical screen attached to the actual linux machine? I have a linux machine with an old 14" LCD that could only go up to 1024x768. My main development machine has 1600x1200 monitors. I found it was possible to have the remote desktop session be at the full 1600x1200 even though the monitor connected to the linux machine could only go up to 1024x768.

Simply use the following command:

xrandr --output VGA-0 --panning 1600x1200

Now your remote desktop session will be displayed as if it were on a 1600x1200 monitor. Development bliss...

If you primary monitor is not "VGA-0", replace "VGA-0" with your monitor. To find out the names of your monitors, just run xrandr without any parameters

xrandr

Creating a Production Rails 3.1 Server (Ubuntu 10.04 LTS)

The following are instructions on how to create a production Rails 3.1 Server using Ubuntu 10.04 LTS

Download the Ubuntu 10.04.3 LTS 64 bit Server ISO from here and install it. Install the "LAMP Server" and "OpenSSH Server" packages when prompted.

Install prerequisites

sudo apt-get install build-essential libyaml-dev zlib1g-dev libcurl4-openssl-dev libssl-dev libopenssl-ruby apache2-prefork-dev libapr1-dev libaprutil1-dev

Download the Ruby source code and compile it

cd ~
mkdir ruby_src
cd ruby_src
wget http://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.3-p0.tar.gz
tar -zxvf ruby-1.9.3-p0.tar.gz
cd ruby-1.9.3-p0
./configure
make
sudo make install

Verify Ruby installed correctly

ruby -v

Expected output is "ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]"

Download the RubyGems source code and compile it

cd ~
mkdir rubygems_src
cd rubygems_src
wget http://rubyforge.org/frs/download.php/75573/rubygems-1.8.12.tgz
tar -zxvf rubygems-1.8.12.tgz
cd rubygems-1.8.12
sudo ruby setup.rb

Verify RubyGems installed correctly

gem -v

Expected output is "1.8.12"

Install Rails

sudo gem install rails

Verify Rails installed correctly

rails -v

Expected output is "Rails 3.1.3"

Install Phusion Passenger

sudo gem install passenger
sudo passenger-install-apache2-module

Configure Apache by adding these lines to /etc/apache2/apache2.conf

LoadModule passenger_module /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.11/ext/apache2/mod_passenger.so
PassengerRoot /usr/local/lib/ruby/gems/1.9.1/gems/passenger-3.0.11
PassengerRuby /usr/local/bin/ruby

Configure your rails application by adding these lines to /etc/apache2/apache2.conf, assuming the name of your app is Mytest. Make sure to change the ServerName to the name of the server.

      <VirtualHost *:80>
        ServerName www.yourhost.com
        DocumentRoot /usr/local/mytest/public
        <Directory /usr/local/mytest/public>
           AllowOverride all
           Options -MultiViews
        </Directory>
      </VirtualHost>
    

Restart Apache

sudo /etc/init.d/apache2 restart

Modify the Gemfile to include execjs and therubyracer if needed. Then run "sudo bundle install"

Rails application housekeeping

sudo bundle update
RAILS_ENV=production rake db:create db:schema:load
rake assets:precompile
sudo /etc/init.d/apache2 restart

Ruby On Rails 3.1 Cheat Sheet

* To create a new application use the rails new command. Replace MyApp with the actual name of your application.

rails new MyApp

---

* If running Ruby On Rails 3.1 on Ubuntu, you will encounter an error stating " Could not find a JavaScript runtime". To fix this locate the Gemfile in the root of your application and append the following two lines

gem 'execjs'
gem 'therubyracer'

then, to update the bundles run the following command

bundle install

---

* To run the development webserver for your application use the following command

rails server

Then from any web browser, navigate to port 3000 of your Ruby on Rails server. In my case the machine name is testror. Substitute with your server name or ip address.

http://testror:3000

---

* To manually work with the sqlite database, use the sqlite3 command followed by the name of the database file

sqlite3 development.sqlite3

To show a list of tables while inside sqlite use the .tables command

.tables

To exit sqlite use the .exit command

.exit

---

* To search for the first record which matches in a database table bound to a model use

@info = Info.find(:first, :conditions => [ "name = ?", "a"])

---

* Variable Scoping

$ - a global variable
@ - an instance variable
[a-z] - local variable
[A-Z] - constant
@@ - class static variable

How to shutdown ubuntu server properly

The right way to shutdown an ubuntu server is simply

sudo shutdown -h now

Notice the -h option. Without that the system doesn't really shutdown and you end up at the Recovery Menu which is really annoying on a headless server.

2.3 Drill Format in Eagle

Just a tidbit for anyone else who runs into this problem. To change EAGLE 4.16r2 to use a 2.3 leading zero drill format modify the following sections of the eagle.def file in your installation of eagle.  The eagle.def file is located in the bin directory of your eagle installation.  Relevant changes are shown highlighted in red.

[EXCELLON]

Type     = DrillStation
Long     = "Excellon drill station"
Init     = "%%\nM48\nM72\n"
Reset    = "M30\n"
ResX     = 1000
ResY     = 1000
;Rack     = ""
DrillSize  = "%sC%0.4f\n"        ; (Tool code, tool size)
AutoDrill  = "T%02d"             ; (Tool number)
FirstDrill = 1
BeginData  = "%%\n"
Units    = Inch
Select   = "%s\n"                ; (Drill code)
Drill    = "X%05.0fY%05.0f\n"      ; (x, y)
Info     = "Drill File Info:\n"\
           "\n"\
           " Data Mode         : Absolute\n"\
           " Units             : 1/1000 Inch\n"\
           "\n"

Just Why does 2.3 leading zero even matter?  I'm not sure it really even does anymore.  Many years ago when batchpcb and golden phoenix PCB first hit the scene they were pretty stringent on the drill file being a specific format.  I think the process of submitting PCBs has advanced far enough now that nobody may even care how screwed up the drill file is, but since I have always had good success sending it in the required 2.3 leading zero format, i figure why change a good thing.  I did recently send some boards to SeeedStudio in a quite messed up drill format and they processed it just fine so maybe nobody really does care anymore.

CGCC now at version 1.01

CGCC v1.01 is now available

small bug fixes

• Fixed a problem with postfix decrementor i.e. "x--" not working
• Added instructions in README to create symbolic link for CGCC.py

Link: CGCC v1.01

Some CGCC Features and Examples

Some features of CGCC
If it works in C or C99 give it a try in CGCC

See the original posting for more info on what CGCC is
Link: Original CGCC Post

This page should give some examples of the capabilities that CGCC already supports.

C Style comments
Multiline block comments can be used to comment out large sections of GCode

// Single Line Comment
/*
Multiline Comment
*/

Declare functions with return values

float AddFive(float i) {
return i + 5
}

Evaluate expressions inside GCode

float x = 1;
float r = 2;
G00 X[x + r / 4]

#Include is supported
Useful for making libraries of functions in header files and including them in your GCode programs.

#include "lib.h"

Assignment from native GCode numbered variables
This is useful in probing operations

x = #1

Directly Emit GCode with the __gcode__ keyword
Useful if you run into a situation where CGCC doesn't handle exactly what you need. You can just emit the correct GCode manually.

__gcode__("(DEBUG, THIS IS A TEST)");

The const keyword to declare constants

const float Radius = 5;

Comparison Operators

== != < <= >= >

Arithmatic Operators

+ - * /

Compiler detects the use of uninitialized variables

Compiler detects use of undeclared variables

Postfix Increment and Decrement

x++
x--

If else statements

if (x == y) {
} else {
}

While statements

while (x != y) {
}