Wolfmans Howlings

A programmers Blog about Programming solutions and a few other issues

A Makerslide based delta 3D printer

Posted by Jim Morris on Sun Dec 16 16:47:33 -0800 2012

UPDATE the project is currently hosted on Github

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Posted in Robotics,3D Printing,Reprap  |  Tags makerslide,delta,kossel,rostock,reprap  |  4 comments

Openbeam self balancing robot

Posted by Jim Morris on Mon Dec 03 02:26:22 -0800 2012

Having some time on my hands I have taken up several hobbies. One is 3D printing, and the other is restarting my robot hobby.

The 3D printing is a whole other story, and I'll probably blog about my adventures in modifying and building a Delta printer soon.

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Posted in Robotics  |  Tags robot,balancing,openbeam  |  3 comments

Groovy bean dialogs

Posted by Jim Morris on Tue Feb 21 16:36:46 -0800 2012

I really wanted to share this one as it is so cool.

I have been writing some database GUI admin tools using Groovy and I use SwingBuilder to build the UI as it tends to be easier than using Swing directly.

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Posted in Java,Groovy,SwingBuilder  |  Tags groovy,swingbuilder  |  1 comments

How to implement Polymorphic protocol buffers in Java

Posted by Jim Morris on Wed Nov 23 00:08:34 -0800 2011

I decided to use Googles Protocol Buffers for a new server. I have been writing custom binary protocols for over 15 years for my various servers, as well as using XML and JSON on occasions.

I prefer binary protocols as they tend to be lean and mean when it comes to bandwidth.

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Posted in Java  |  Tags netty,protocolbuffers  |  6 comments

How to setup SyntaxHighlighter in Rails 3.1.1

Posted by Jim Morris on Sat Nov 12 01:36:29 -0800 2011

Or how to get Rails 3.1.1 assets in vendor/assets to work in production.

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Posted in Rails  |  Tags rails,syntaxhighlighter,assets  |  2 comments

Turn off forgery protection when using caching

Posted by Jim Morris on Sat Dec 18 01:04:06 -0800 2010

This one does not seem to be documented, and I just got bit.

After porting my blog engine to Rails 3, I noticed that after a while comments were being rejected with an ActionController::InvalidAuthenticityToken error.

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Posted in Rails  |  Tags rails,authenticity  |  4 comments

Upgrading a Rails 2.2.2 app to Rails 3

Posted by Jim Morris on Fri Dec 17 15:27:17 -0800 2010

After porting my blog engine from Merb to Rails3 code here I thought I'd upgrade my Snow Dogs R Us Site (aka dogz.us) to Rails 3.

It was written in Rails 2.2.2 so I figured it would not be too hard, well it was easier to port my Merb App than it was my Rails app!

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Posted in Rails  |  Tags upgrade,rails3  |  3 comments

Upgrading a Ubuntu Dapper 6.06 server to Lucid 10.06 with software RAID 1

Posted by Jim Morris on Mon Nov 29 23:06:57 -0800 2010

I needed to upgrade a remote server that was running Dapper to Lucid, as Dapper is no longer supported (or will soon be EOL'd). This server uses a software RAID 1, and that seems to be the problem.

I tried to do this over the network via ssh in a screen, however after it upgraded to Hardy it failed to boot.

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Posted in Linux  |  Tags ubuntu,dapper,lucid,upgrade,raid  |  no comments

A Simple Challenge Response authentication scheme for Rails3

Posted by Jim Morris on Mon Nov 29 23:06:41 -0800 2010

UPDATE the following is for pre rails 3.1, there is an addendum at the end for rails 3.1+

I have ported my blog engine (that hosts this site), from Merb to Rails 3. You would expect it to be fairly simple as Rails 3 is meant to be the next version of Merb.

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Posted in Rails  |  Tags authentication,javascript  |  no comments

Running Erlang OTP applications as Daemons on Ubuntu Servers

Posted by Jim Morris on Sun Sep 19 17:26:42 -0700 2010

Recently I needed to deploy an Erlang OTP application to a production server, and was surprised at the lack of official documentation on how to do that. My requirements are to have the application run on system startup, and if the application crashes to have it automatically be restarted, some optional requirements are to have rotated logs and to get email notifications if the application does crash.

Erlang itself has several layers of supervision to keep its processes running, however on occasion the VM itself may crash, if it runs out of memory for instance. I would want the entire appliction to be restarted in that case.

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Posted in Erlang  |  Tags erlang,OTP,daemon  |  2 comments