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A water rocket is a type of model rocket using water as its reaction mass. The pressure vessel (the engine of the rocket) is constructed from thin plastic or other non metallic materials (usually a used plastic soft drink bottle) weighing 1,500 grams or less. The water is forced out by compressed air. It is an example of Newton's third law of motion.

Electronic Safety Measures

Discussion about deployment systems including altimeters, timers, air speed flaps, servo systems, and chemical reactions.
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Mark Chen
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Electronic Safety Measures

Post by Mark Chen » Mon Jan 07, 2008 11:50 pm

Hey does anyone out there know much about electronics? We're looking for a circuit that we can use to control our rocket payload from a distance. We just need to turn on the altimeter and start up our camera. We thought about cannibalizing a R/C toy, but there must be a better answer. Anyone have any suggestions?


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Re: Electronic Safety Measures

Post by Spaceman Spiff » Tue Jan 08, 2008 3:15 pm

Mark Chen wrote:Hey does anyone out there know much about electronics? We're looking for a circuit that we can use to control our rocket payload from a distance. We just need to turn on the altimeter and start up our camera. We thought about cannibalizing a R/C toy, but there must be a better answer. Anyone have any suggestions?
Maybe you can get the guys from USWR to give some tips because they're the ones who basically invented the remotely operated rocket computer. I remember reading about it on their site.

Ah... here it is. Google is my friend!

http://www.uswaterrockets.com/science/s ... ory_04.htm

You don't need all the features but I bet it would be easy to simplify their idea!


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Post by Mark Chen » Tue Jan 08, 2008 6:20 pm

I sent them a PM and linked to this topic. I tried to use google to find something similar and nobody else out there has done this kind of thing before. It's hard to find anything about rocket controller electronics much less remote operated ones. The only thing I can find is deploy timers and pin pullers.


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Post by Tim Chen » Tue Jan 08, 2008 10:16 pm

Mark Chen wrote:I sent them a PM and linked to this topic. I tried to use google to find something similar and nobody else out there has done this kind of thing before. It's hard to find anything about rocket controller electronics much less remote operated ones. The only thing I can find is deploy timers and pin pullers.
If you guys are reading this, I've been taking some programming classes, so I know Visual Basic, and some Java. Is there anything I should be studying in addition to this?


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Post by U.S. Water Rockets » Thu Jan 10, 2008 9:47 pm

Hello Tim and Mark,

If you can program in the C language you have your choice of many options. There are literally dozens of small experimenter kits and robotics kits for you to pick from.

If you're comfortable with BASIC, a company called Parallax makes a series of project kits called the "BASIC Stamp". The stamp kits are very small and have been around for a long time so they're probably well made and easy to use. There should be plenty of online help in the community for this line. Don't expect any high performance code with these because it's BASIC, after all, and the CPU that powers these things is a little (really a lot) long in the tooth and was considered very weak and quirky when it was new.

Parallax is pushing a new CPU with multiple cores which looks interesting, but it's not as popular as other offerings in the same price range. There's not nearly as much out there for it.

You should easily be able to find a kit that does what you need and this will enable you to come up with the software to control your rocket on your desktop. Once you have that worked out, you can then take the schematics of the kit and reduce them down to the bare minimum components you need and assemble your own board.

You could also opt to just come up with a schematic on your own and breadboarding the design yourselves. You don't sound like you need the kind of R/F remote we use, so you have a lot of options for easier and less touchy alternatives. R/F design can be rather tricky and so you might want to just use something simple like mechanical switches with pull-strings or magnetic switches or even light sensors to control your payload. There's plenty of designs out there for this sort of thing.

The good news is that there's a ton of work out there to draw from and there are other areas which you have not ever mentioned which may apply to your Payload Controller. For example, you could use servomotors to control your deploy system. Loads of examples and code exist for this exact type of thing in the R/C and robotics communities.

Good luck with your project, and thanks for writing!



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Post by Mark Chen » Fri Jan 11, 2008 1:06 pm

Wow! Thanks a whole bunch for the info USWR! I have heard of the BASIC Stamp before and I'm looking at their site right now. This looks like it could be just what the doctor ordered! Thanks for the input!

What do you guys use for your rocket computer, if you don't mind my asking?


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Post by Tim Chen » Sun Jan 13, 2008 11:37 am

U.S. Water Rockets wrote:Hello Tim and Mark,

If you can program in the C language you have your choice of many options. There are literally dozens of small experimenter kits and robotics kits for you to pick from.

If you're comfortable with BASIC, a company called Parallax makes a series of project kits called the "BASIC Stamp". The stamp kits are very small and have been around for a long time so they're probably well made and easy to use. There should be plenty of online help in the community for this line. Don't expect any high performance code with these because it's BASIC, after all, and the CPU that powers these things is a little (really a lot) long in the tooth and was considered very weak and quirky when it was new.

Parallax is pushing a new CPU with multiple cores which looks interesting, but it's not as popular as other offerings in the same price range. There's not nearly as much out there for it.

You should easily be able to find a kit that does what you need and this will enable you to come up with the software to control your rocket on your desktop. Once you have that worked out, you can then take the schematics of the kit and reduce them down to the bare minimum components you need and assemble your own board.

You could also opt to just come up with a schematic on your own and breadboarding the design yourselves. You don't sound like you need the kind of R/F remote we use, so you have a lot of options for easier and less touchy alternatives. R/F design can be rather tricky and so you might want to just use something simple like mechanical switches with pull-strings or magnetic switches or even light sensors to control your payload. There's plenty of designs out there for this sort of thing.

The good news is that there's a ton of work out there to draw from and there are other areas which you have not ever mentioned which may apply to your Payload Controller. For example, you could use servomotors to control your deploy system. Loads of examples and code exist for this exact type of thing in the R/C and robotics communities.

Good luck with your project, and thanks for writing!
Thanks for the help. I have a module on order and also some of these really tiny servomotors. They weigh only 10g and will possibly be the lightest deploy system we've ever made. I'm going to try and put all the functions in one computer like you do.


Tim Chen
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