Flight Computers Redux

[Warren B. MusselmanModerator]

I’ve been working for some time on a fully programmable data acquisition and telemetry downlink package that will eventually contain full flight controls for complex rockets. After much fiddling about and research, I’ve finally settled on the gumstix SBC – a full featured Linux single board computer the size of a stick of Wrigleys gum that weighs 8 grams. (http://www.gumstix.com) Aside from the fact that it is a fully linux computer, it also has bluetooth and Wifi options as well as full wired Ethernet and the capacity to add an arbitrary amount of on-board memory via Compact Flash and SD memory cards.

My initial implementation will be for GPS acquisition in binary mode from a SirF based 20 channel GPS chip (USGlobalSAT ET-301). The RS-232 wireless chipset is the Radiotronix RK-Wi.232FHSS-250 which is a 250 mW full-duplex RS-232 wire replacement interface with a range of up to 7 miles LOS. Testing has shown I can maintain 2400 baud out to 7 miles LOS with the rubber ducky antennas and substantially higher baud rates with directional antennas. (Up to 256K baud within 2m).

What I’m looking for is anyone who has hands on experience developing for the Gumstix line of SBC’s or who has experience designing and laying out PCB’s for surface mount. I’d like to team up with someone to push this project further down the road towards a packaged product. In addition to integrating these three packages, I also want to develop a 3 axis accelerometer module, an absolute pressure barometric sensor, and input signal conditioning for a pull-pin and/or first-motion detector. On the output side, I want to develop an 8 to 12 channel high current output module to allow for igniter and/or ematch firing.

Anyone interested in joining the team?

Warren

[MikeSModerator]

My Lord! 😯

[Jeffrey Joe HintonModerator]

Isn’t it great when geek speak leaves one breathless; it’s like a O4500 in an upscaled Alpha. What kind of power source and how much would be necessary to activate all the bells and whistles? I’m no electronics wizard but could probably help with funding or grant searching.

[Doug GerrardParticipant]

Warren, I’ll forward your posting on the a couple of guys I work with that might be interested it joining your project. They have talked about doing the same sort of thing for a while now but not with chewing gum 😉 Still they have a lot of experience designing and laying out high speed data boards. I’ll let you know.

Doug

[Doug GerrardParticipant]

Warren, I got a favorable response. I sent you an e-mail with some details.

Doug

[Bret PackardParticipant]

I have no idea what all that meant, but it sounds very cool! Good luck with the development Warren.

[Bruce R. Schaefer]

Sorry, Warren. 4-5 years ago, I could have done everything myself. While I still have the software to design and provide the correct Gerber files, that was too long ago now. I still plan to pick the lifelong hobby of electronics up again and use that software, but too much going on now. I think Doug put you in touch with the right people. It’s a wonderful project, absolute best of luck, and keep us informed!

[Warren B. MusselmanModerator]

I’m in touch with a buddy of Doug’s and moving forward. Other folks, particularly math-involved programmers or sensor involved hardware guys are welcome to step up to the plate and will be much appreciated.

Warren

[Bruce R. Schaefer]

I used to program firmware in C, and that’s what you’ll need. I know there has to be a few geeks in the club who do it. The guys that Doug suggested surely know how to use digital sensors, and there has to be a C programmer in there somewhere. The thing is bring your software guy in soon enough so he can plan things out as this goes along. He’ll need to know what addresses are being used and for what, specific math algorithms he’ll be using, he’ll write small test scripts so you can check things out, etc. Most of what he’ll need will come with the hardware fact sheets. This really sounds like fun. I wish I had the time.

[Mike Bennett]

So I have no experience with the gumstix, the fun part is the two different data streams. GPS data and live telemetry at the same time over the same serial downlink unless you plan to do them separate the downlinks with 2 transmitter/receivers.

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