Serious rocket hobbyists aren’t content with merely launching their rockets into the air. [wwgd] wants to have an on board computer to control his flights and log the data. He doesn’t quite know how to do it all yet, so he’s starting with the basics. He has built the basic GPS data logger using an accelerometer, a GPS unit, and a BS2P microcontroller. The overall weight is 62 grams and it can record for the whole 5 minute flight. At roughly $200 though, we’d be thinking twice before launching it into the stratosphere.
stratosphere? geez what kind of rocket are we talking about?
but still, it’s cool. too bad he’s using a basic stamp. could stick a pressure sensor in there yet to get more accurate altitude data.
Wii nunchuck ($10) + Arduino nano ($50) + Sparkfun GPS ($60ish)…
easy to use, arduino has a small amount of flash and eeprom memory you can access, lightweight, and cheap(er).
I’ve been thinking about doing something similar, except I’d use just an AVR instead of a full arduino. Power it off some supercaps for quick charging between flights, and saving weight. Goldmine elec has some cheap.
He could use an XBee with it so the GPS data can be recorded remotely so he can find his $200+ rocket if he loses it.
this kinda makes me wish i were born 20 years later. it’s one of the few memories i have created with my dad, model rocketry.
Just don’t lie to it about the mission.
Trust me, it would be bad.
I think this is OK, but I believe that reporting data during flight (as with an xbee) actually violates some sort of FAA rule or something. like tracking systems count as guided missiles and require a permit. I only barely remember it from my rocketry days.
rt (panzer time!) :
I bet it’s illegal much in the way silencers on paintball guns are illegal. It’s against the law, you could get serious time, but nobody’s ever been in major trouble because of it, and likely won’t be in the future. I like to think that the US legal system at least typically distinguishes between what is against the law in a literal sense, and what is against the spirit of the law (as well as literally).
But then things like the Boston ATHF terrorist attacks make me lose hope…
It is actually perfectly legal to log data on the flight, even transmit it down to ground, although transmitting guidance info back up is starting to get into a gray zone.
In any case, this project looks like a great start on the way to a decent logging GPS tracker, although I would really recommend moving away from the many flying leads and tons of connectors his system has, I have found the number 1 cause of failures in my trackers if glitches caused by connectors coming loose during the motor burn and more often the ejection charge. I am currently working on a 4th revision of my tracker, which has all of the components (including the gps receiver, battery, 500mw 900mhz downlink, and all of the sensors) soldered down to the board to eliminate this problem.
see my sig or http://krazerlasers.com/gps for my system
I assume the ITAR restrictions of the gps
are not a big issue here?
http://www.fas.org/spp/starwars/offdocs/itar/p121.htm
Lots of good first hand info about gps tracking (with weather baloon instead of rocket) to altitudes of more than 30 km.
http://www.natrium42.com/halo/flight2/
Yeah, i remember that. I saw it about a yr ago.
but it’s still fucking awsum! :)
I would suggest not letting off model rockets wearing a turban as wearing one seems to mean you are a terrorist these days. The last thing you want is being called a terrorist when you are out launching rockets with your kids for fun.
I like this…but the same low cost telemetry in a stable model aircraft would have more appeal
Someone needs to introduce my man to Arduino: the BASIC stamp killer. Cut that price in half. Not to mention faster/more efficient and who really likes writing BASIC anyway?
>who really likes writing BASIC anyway?
people who dont know programming and just start learning
in response to cyrozap, i kinda had some idea on this a while back, sort of a low cost lojack system using an arduino, gps logger and xbee. have the gps logger use the xbee to report to any open access points and basically use a twitter account to track the GPS location of say a stolen motorcycle in my case… maybe i’m crazy, but i want to do it…
Given the parts list, this is stupid. Last I checked the same GPS sensor thats in my Garmin 60csx is like $15 or something, I can get a tracfone with the battery and some other parts, for $10. You dont put expensive crap in anything you dont expect to perhaps never see again.
I should draw something up…
I notice it too, he spend a way more than can for something what have a 50% chance of being lost or burned
While not illegal to make this setup, it is illegal to make a rocket controllable in more than 2-axes. Also depending on the G-Load in flight his GPS (at least) will fail. most crap out at about 5 Gs some at 20Gs. You need gov’t grade quartz crystals and the system needs to be potted in epoxy to prevent damage in flight.
Also, to prevent missiles from using GPS; the system wont help you if youre over say, 400 ft/s (not sure about that value anymore)
I have never heard of “crystals” being required to run GPS at higher velocities. There are many commercial grade GPS datalogger/telemetry products on the market specifically for rocketry and they do not mention anything about “special crystals.” ?? I will look more into this, later tonite.
In order to cut cost and raise performance, I plan on using a cheaper/lighter antennae ($40) and a Propellor chip. I know of no other company that offers a multi-core microcontroller for $18. ?? I have never worked with the Spin object oriented language that runs it, I assume it is a bastard child of Java much like PBasic is a bastard child of Basic.
For those of you who are familiar with the performance of the Stamp series microcontrollers, a Propellor in-a-nutshell is equivalent to controlling 8 Stamps simultaneously.
Muti-tasking is so 20th century.–Particularly for a microcontroller.
After a casual search, the velocity cutoff for GPS data sentences is 1000 knots or 1150 MPH or 1688 fps. Anything that travels below this threshold can recieve GPS signals sucessfully. USA made GPS receivers must be limited to the above threshold if exported to another country.–So theoretically, My USA made receiver can perform above the threshold because it never left the country. ??
Unfortunately, my time and pocketbook dictate I stick to toiletpaper tube airframes. I wonder how well a BT-60 would hold up at 1150+ MPH?
The threshold also explains the need for epoxying the circuit.–At 1150+ MPH it would be needed.
The threshold is designed to eliminate civilian GPS receiver use in improvised ICBMs.
I am at the end of my TL-96 rocket build which will carry my GPSDL into the Troposhere at well under 1150 MPH.
If I have to I could always facet my own crystals overcoming the government export restriction! I think I read an article about it on makezine.com
Really cool blog. I found it on yahoo. I am looking forward to read more posts.
Can anybody tell me what�s the best hotel in Paris for my honey moon? I going to married next month..
Thank you