WEther Balloon (WEB) Project – Antennas

Original Dipole design with BNC connector.
There are many different antenna designs that I considered for this project. After considering a dipole mounted on the payload tie line I eventually found a major problem with this design. A dipole antenna transmits in all directions except for the poles. So my transmitter would be wasting power transmitting out into space and stations directly below the balloon would have limited reception. I eventually decided on an inverted quarter wave ground plane (QWGP) antenna. The QWGP is perfect because when inverted it will direct all of its power in a hemispherical  direction toward the ground. The antenna I came up with was based on a SMA connector, music wire (.025″ dia.) and square brass tube. I soldered the brass tube to the connector to create the framework for inserting the music wire elements. This makes for a super light weight flexible ground plane antenna. It only weights 16 grams!

The ground plane antenna that I cobbled together was found to have a SWR of 1.10 at 144.39MHz and a minimum SWR of 1.04 at 102.00MHz. We also tested the output of the HX1 and found that it’s actual frequency spectrum was within the values stated on the spec sheet. These steps were not critical but it is good to know that the antenna system is functioning at a optimum level and that the HX1 is working as stated in the spec sheet.

All of the analysis was all done at the Conejo Valley Amateur Radio Club Headquarters. The club has been extremely knowledgeable and eager to help out. Special thanks to Rob Hanson (W6RH), Hugh Bosma (AE6YC) and Terry Graves (K7FE) for the technical consult and analysis. Another useful resource is the Antenna Myths Presentation Slides by Terry Graves (K7FE)

WEther Balloon (WEB) Project – Payload Enclosure (Part 2)

The enclosure was a bit uneven so I shaved the corners smooth with a sharp razor blade. The camera hole was cut into the side of the box. I chamfered the area around the hole to allow an unobstructed  view by the camera. After shaping the styrofoam the  external surfaces were sprayed with contact cement. I adhered a space blanket to the outside of the enclosure. Finally taping the corners with orange duct tape for stability and to aid in visually locating the payload.

I came across a problem. The camera and styrofoam created a ghost image on the lexan window. So I ended up gluing black felt to the aperture as well as painting the chrome bits on the camera flat black.

To mount the camera I used velcro strapping glued to the camera and enclosure. This firmly mounted the camera to the enclosure without adding the weight of extra hardware.

WEther Balloon (WEB) Project – Payload Enclosure (Part 1)

I started work on the payload capsule today. Using a 2 inch thick Styrofoam sheet I found I cut out panels with a long x-acto knife. I will join the panels together with Gorilla Glue. Now, usually I hate this particular brand of glue. It is messy and while curing it foams to many times its original volume. But the key for this project is its non-solvent nature and the foaming.  Non-solvent means that it won’t eat up the foam like other adhesives. The foaming is a huge benefit in this application because it will fill in any curved cuts or misalignments. I would have to say that for this particular application Gorilla Glue is perfect. The glue is as simple as wetting one side of the mating panels and applying a generous amount of glue to the other.  After the glue was no longer tacky one can just peel the foam that ran out of the gaps off. It makes an airtight seal that appears to be part of the styrene.  Lastly I shaved the edges off the box so that the corners weren’t as sharp. 

WEther Balloon (WEB) Project – Trackuino

For about a year now I have been researching the hobby of high altitude ballooning (HAB). It all started with some photos I stumbled upon by a Brit named Robert Harrison (The Icarus Project). After researching many different tracking methods I discovered the most common was the Automatic Position Reporting Systems (APRS). This tracking method requires an amateur radio license in the United States as well as many other countries.  So I went out and earned my Technician Class license which permits me to utilize the 2 meter VHF band where the standard APRS frequency lies, 144.39MHz in the U.S. Right after this time I began looking for a suitable APRS transmitter for a HAB. After becoming frustrated with the proprietary closed source offerings available the market I turned to looking for an open source alternative.

This is when I found the Trackuino project. It was started by Javier Martin (blog). It is an open source APRS tracking module based on the popular Arduino platform complete with onboard transmitter, GPS module, cut-down control and two LM60 thermometers. He had the schematic and source code to run the module completed and ready to run but was looking for someone to help with designing the circuit board. I had done a few boards before so I offered up my services.

We used Sparkfun’s batchPCB circuit board prototyping service to supply the boards and Javier was very kind to supply me with a few boards for testing and my own HAB project. The Trackuino works like a charm. It is fairly simple to re-flash with new software and the source code is easily edited because of liberal comments describing the design and use of each function.

I will continue to update this post as the project progresses.

Soldering Surface Mount Components

Using a electric skillet I bought from Target I have been experimenting with soldering SMD components. Using a thermocouple on my multimeter, stopwatch and skillet I have been manually emulating a standard reflow profile.

By first marking the average temperature at each of the knobs settings, LOW, MED, HIGH, I am able to predict the approximate dial setting for the desired temperature. Then using the stopwatch the correct time duration can be waited before moving on to the next temperature.

Open Source?

I have been thinking of making this site based on open source hardware for awhile. With the development of the canduino I have decided to shift the focus of this site to one of opensource development. I am hoping to demonstrate the value of the controller area network protocol for many projects with a simple easy to use shield and library.

As for the boostbrick…

The development of the boostbrick has been delayed indefinitely because of my schedule. I just don’t have the time right now to finish the project to my satisfaction. I am going to continue work on this project when I can. I will release the schematics and code once a reliable device is finished.

Canduino update

The canduino shield I have been thinking about for a while is about to become reality.
I am hoping to start this project to bring controller area network communications to beginner arduino users.

http://code.google.com/p/canduino/

Controller Area Network for Arduino based projects…

Canduino V2 Controller Area Network For Arduino
Canduino V2 Controller Area Network For Arduino

Canduino V2 Controller Area Network For Arduino

Bus Pirate Pinout

Color code chart for the sparkfun bus pirate pigtail. Not much else to say…

enjoy!

BoostBrick First Look

Here it is…

The first  BoostBricks are here and almost ready to go.

BoostBrick

Canduino

One side project I have been working on is an easy way to use CAN 2.0 on a Arduino.

The Project page can be found here.

Not much going on yet but I hope to have a prototype shield done soon.
Any help designing the software library would be appreciated. This particular is designed to be an open source project to help beginners and experienced electronic enthusiasts promote one of my favourite communications protocols. CAN is highly useful but seems to be bypassed in place of other slower methods like TTL serial.

  • What are we about?

    Crockett Engineering's mission is to manufacture the finest in aftermarket controller electronics. Our products find the ever elusive balance between form and function.

    As well as to create innovations, not inventions, but to greatly improve on existing technologies through open source, community based projects.

    And to add value by educating.

  • Philosophy

    Crockett Engineering was founded on the belief that the best control systems don't have to be the most expensive.

  • Tags