cutdown is an Arduino-based launch stack cutdown system for HackPittsburgh's high-altitude balloon.
HackPittsburgh is working on a high-altitude balloon project. Tonight I was pressed into service to develop a launch stack cutdown system that would switch voltage to a nichrome wire after passing a target altitude to separate the payload from the balloon. With not a single bit of hardware in sight, I hacked together this monstrosity.
Balloon launch photos should be available at the HackPittsburgh Flickr Pool.
- Arduino 0018 (http://arduino.cc)
- NewSoftSerial 10c (http://arduiniana.org/libraries/newsoftserial)
- TinyGPS 9 (http://arduiniana.org/libraries/tinygps)
Refer to the installation instructions on the Arduino website to install the development environment. To install the required libraries, assuming you are using a modern Arduino environment, simply unzip them to their own directories within:
There should be plenty of online documentation describing this process.
To use cutdown in your project, you must ensure that a few preprocessor definitions are accurate, and you must of course wire up the proper circuit. The best place to see what is required is in the code itself. If you have any questions, email me.
cutdown is completely and utterly untested. The code compiles, and that's all. I tried to be careful with the coding and design, I read the TinyGPS and NewSoftSerial documentation and examined the library code, and I did a code walkthrough with a peer. Nevertheless, I haven't actually run this thing, as hardware was unavailable and time was tight. Caveat emptor.
- Initial release (totally untested)
- Fix a bug where cutdown target altitude was specified in feet but TinyGPS returns altitude in meters
- Still totally untested :)
Jon Speicher (firstname.lastname@example.org)
cutdown is pretty dumb. For the most part, it just ties together existing software, and so credit is due to the author of NewSoftSerial and TinyGPS, Mikal Hart.
The MIT License Copyright (c) 2010 Jonathan Speicher Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.