My Personal Blog

Using Arduino to Transmit and Receive RF

2012-01-14T22:32:00.001-05:00

I have been playing around with a 434MHz RF Transmitter and 434MHz RF Receiver from Sparkfun so that I can transmit and receive RF signals between two Arduino micro controllers. After a couple of unsuccessful attempts using the tutorials from the product page, I finally managed got the equipment to work using the transmitter.pde and receiver.pde code from the Arduino Library. I modified the receiver code to receive ASCII intend of HEX responses from the receiver.

The equipment I needed:
1 Arduino Uno R3
1 Arduino Duemilanove
1 RWS-371-6 Wireless Hi Sensitivity Receiver Module (434MHz)
1 TWS-BS Wireless Hi Power Transmitter Module (434MHz)
1 Breadboard
11 Wires
2 USB cables to connect to the Arduinos

I experimented with some different configurations but I managed to get results connecting the transmitter to the 3.3V or 5V power supply and connecting the data lead to pin 12 on the Arduino. The receiver could only be connected to the 5V power supply and the data lead to pin 11 on the Arduino.

XSL Transformations for Blogger and Delicious RSS feeds using Coldfusion behind a proxy at Godaddy.com

2010-06-20T15:50:00.002-04:00

The process for syndicating an RSS feed from Blogger or Delicious was a little more complicated than I had imagined. I thought others might benefit from seeing the Coldfusion code that enables me to share content from these services in an effort to increase search engine optimization of my website by reusing keywords and content that would otherwise be lost on the hosted websites.

Coldfusion Environment
The Coldfusion 7 hosting service at Godaddy.com has been excellent since it provides many other programming languages such as PHP, Java, Perl, Microsoft .net, and Ruby on Rails for me to work with. The only problem I have had so far is to remember to work around their proxy and not being able to upgrade to Coldfusion 9.

Blogger.com Syndication
Here is a function I created to consume my blog hosted on blogger to create my blog webpage, notice the proxy server and proxy port variables:

This function needs the Extensible Stylesheet Language (XSL) file referenced in the code as blog.xsl (just look at the source of the this webpage) to style the Atom RSS feed. I added a test for summary or full output of the blog which is set in blogger at Settings > Site Feed > Allow Blog Feeds.

The results of the of this function are stored in the displayXML variable and can be displayed on the page using this command: #displayXML# surrounded by cfoutput tags.

Delicious.com Syndication
This function is identical to the one above but it references link.xsl (click here and view the source) and powers my links page.

If you have any questions please comment or contact me.

VNC Server Setup

2010-06-19T20:44:00.026-04:00

I recently set up an Enterprise Linux environment on a server I have running at home. One of the first things I wanted to set up was a VNC Server so I can remotely manage the box without having to physically be logged into the machine. Setting this up this service didn't seem to be a problem at first, following this guide got me going but I soon found that using a VNC client over an SSH tunnel wouldn't work unless my account was logged in.

The problem: I would log into the service using the VNC client and receive my login screen from the server, but after inputting my password the screen would go black and nothing else would happen.

I found many potential answers by Googling but all seemed to point at the firewall to solve the issue. I opened up internal firewall ports 5900 and 5901 as indicated by this guide in an attempt to find a quick solution but this didn't seem to help. After talking with a colleague he suggested that I check what account I had started the VNC service from to ensure the proper permissions were being accessed during the transaction.

Solution: In my case the VNC server was started under the account that I had planned on using to access the VNC Server, however I needed to start the service under the root account instead. After changing to the root account everything worked correctly.

Server Configuration Steps:
1) Set up VNC Server
sudo vi /etc/sysconfig/vncservers

2) Change the default configuration to add the users that will run the service
VNCSERVERS="1:username"
VNCSERVERARGS[1]="-geometry 1024x768 -depth 16 -AlwaysShared"

3) Edit the user home directory xstartup file
vi /home/username/.vnc/xstartup

4) Uncomment the following two lines for normal desktop:
unset SESSION_MANAGER
exec /etc/X11/xinit/xinitrc

5) Open internal firewall port 5901

6) Set VNC Server password
vncpasswd

7) Start the VNC Service as the root user
sudo vncserver :1

Connection Steps:
1)Open a shell client and tunnel the VNC port through the local session:
ssh -L 5900:localhost:5901 username@xxx.xx.x.xxx

2)Start the VNC Client
home:127.0.0.1:0

SSH Encryption For Your Web Connections

2010-06-16T06:18:00.003-04:00

The latest episode of Hak5 inspired me to set up a SSH proxy to encrypt my web traffic to prevent anyone from seeing my data. The tutorial on the page was very helpful, here is what I had to do to get it to work on my MacBook Pro running OSX 10.6.4:

1) Run the command below in the terminal
ssh -ND 9999 username@xxx.xx.x.xxx

2) Open "Network" under Apple > "System Preferences..."

3) From the "Location" drop-down, select "Edit Locations", then select the gear sign and "Duplicate Location." In my case I duplicated my "Automatic" location and named it "Secure Proxy".

4) Click "Done" to close the "Edit Locations" dialog box.

5) Select your new location from the Location drop-down.

6) Click the "Advanced..." button in the lower right.

7) Click "Proxies" and select the "SOCKS Proxy" checkbox.

8) Fill in "localhost" for the SOCKS Proxy Server value and port 9999 in the box after the ":" symbol.

9) Select "OK" to close the "Advanced..." dialog box, then click "Apply".

10 In Firefox, go to Firefox > "Preferences... > Advanced > Network > Settings and select "Use System Proxy Settings" option box.

11) Select "Ok"

12) Safari automatically uses the System Preferences so you don't need to worry about that browser.

Now whenever you want to switch to proxy mode, just start your client and select your "Secure Proxy" location.

Maiden Voyage

2008-06-06T04:42:00.000-04:00

Today I completed the first successful maiden voyage in my sailboat. The plan was to launch from a boat ramp in Port Orange and sail to disappearing island but after gaining enough courage to venture out of launching area I shortly found that I do not know how to read the channel indicators in the intercoastal waterway and was soon scraping the bottom on oysters. Rigging the boat took about two hours to get everything hoisted, tied, and situated.

Painting the Boat Trailer

2008-06-02T04:40:00.001-04:00

My first project for the boat will be to fix the lighting on the trailer as well as sand off all the rust and paint it with Rust-Oleum. I have chosen the smoke grey enamel color (Number 7786402) that comes in a can so I can brush it onto the trailer. I also bought an LED light kit and side markers to replace the current non-working lights.

The light kit was easy to install but I am not satisfied with the brightness of the lights so I will need to research ways to make it brighter.

Painting the trailer is a slow and tiring process since the trailer is covered in rust each section takes nearly 2 hours to get to the bare metal. I went ahead and bought an electric sander for the project but I soon found that it was not designed for this type of sanding.

Sailboat Naming

2008-06-01T04:37:00.001-04:00

As everyone knows you must name your boat so I have compiled a list of possible names ranked from the most desirable.

She's almost 18 - This is funny because the boat is 17 ft. 9in. long...
One Ping Only - From the movie "Hunt for the Red October".
iBoat - The latest Apple gadget!
AFK - Stands for away from keyboard but mostly used by nerds so I doubt anyone would get it.
The Pearl - From the movie "Pirates of the Caribbean".
PWNED - Another nerd reference.
Giggidy Giggidy - From the TV show "Family Guy".
The Other Woman
SpaceBall 1 - From the movie "Space Balls".
88 knots per hour - A reference from the movie "Back to the Future".
Kelly - My friend Kelly suggested that I name it after her.
Cupcake - Some girl asked me to name it this a long time ago.

Bought an O'Day Sailboat

2008-05-30T04:36:00.007-04:00

Today I picked up my O'Day sailboat from Sebastian, FL. The boat is much bigger than I had pictured it from the photos that were posted on Ebay. The boat is 17 feet long and has a mainsail, jib, and a spinnicker. I am really excited to take her out on the water and see what she can do.

Pictures of the boat on Flickr

Memorial Day Activities

2008-05-27T12:22:00.005-04:00

This Memorial Day turned out to be a lot of fun. I saw the latest Indiana Jones movie with some friends, attended two parties, traveled to Jupiter FL, met an old friend at the beach, and bought a sailboat. I am hoping that the sailboat will give me a new love for living so close to the water and give me an opportunity to meet some new friends along the way. I am thinking up some names for her and have started a blog for all of the projects, trips, and adventures I will have with her along the way. I will soon link all of my blogs within my website.

Relaxing

2008-05-15T16:24:00.006-04:00

Relaxing
Originally uploaded by Stephen Kropp

The past week I have been relaxing in my hometown, Kansas City and it has been great. Seeing my friends and family made me want to take another week off and delay the inevitable trip back to Daytona. I have noticed that the people my age in Kansas City are much nicer than those I meet in Daytona. For now I am going back to the daily grind I have fallen into in Daytona Beach.

Slideshow of pictures

Process Optimization by Design

2008-04-27T10:16:00.004-04:00

I have been looking for a thesis topic and started a research project with two local companies in Melbourne. We are interested in optimizing the software development processes currently employed at one of the companies. The project has been pretty interesting so far and will be expanded in the future.

Bike Week 2008

2008-03-14T12:39:00.001-04:00

Bike Week 2008
Originally uploaded by Stephen Kropp

I recently acquired an intro sport bike that has proven to be a lot of fun around the area, especially during Bike Week. I have never really enjoyed this week of loud exhausts and crazy bikers in the 8 years I have spent in Daytona but going around with friends has been a lot better behind my own motorcycle. My friends and I all took off the day from work and rode all around to see the sights of bike week. We started at the Cabbage Patch where we saw women's coleslaw wrestling at its finest, then headed to main street to see the hundreds of bikes and people all gathered for the yearly event.

Sileshow of Pictures

Leopard Install Issues

2007-12-21T00:58:00.002-05:00

After attempting to install Mac OS 10.5 (Leopard) my computer has me locked out of my own user profile. I have managed to recover the encrypted data but I had to restore my user account.

Drew Graduation Photos

2007-06-16T13:00:00.002-04:00

Lora, Drew, and Mom
Originally uploaded by Stephen Kropp

Drews graduation photos from Ray-Pec High School

View Slideshow of Photos

Lora Graduation Photos

2007-06-16T04:41:00.002-04:00

Mom is Proud
Originally uploaded by Stephen Kropp

View photos from my sister's graduation from the University of Tulsa.

View Slideshow of Photos

Oracle Open World Trip

2006-10-19T20:40:00.003-04:00

Oracle Open World was a great experience. The conference was huge with nearly 40,000 attendees, all of which were looking to learn more about the latest and greatest Oracle has to offer their company. My reason for attending the event was to get up to speed on the Oracle technology that found in my workplace (Embry-Riddle). I packed each day starting at 8 full of interesting classes and presentations on the latest technology which would usually extend a little beyond 5:30pm. It was unbelievable how the city was transformed with Oracle buses, posters, displays, and anything else that could be painted red. It seemed that nothing was too over the top for this event, one of the singers for the event turned out to be Sir Elton John. I learned a lot from the entire experience and really got me excited to explore all that Oracle could offer.

Photos from the trip.