Rocket Robot - Miscellaneous
Bruce Bates
Posts: 3,045
Mark -
The cover I had in mind is a dome, so I doubt that would work very well. I'll see what else I can locate for you.
Regards,
Bruce Bates
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"Genius is one percent inspiration and ninety-nine percent perspiration."
Thomas Alva Edison
The cover I had in mind is a dome, so I doubt that would work very well. I'll see what else I can locate for you.
Regards,
Bruce Bates
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"Genius is one percent inspiration and ninety-nine percent perspiration."
Thomas Alva Edison
Comments
I am concerned about the thumb drive. It is a mechanical issue about the way it sticks out like a potentially sore thumb in a system that is bound to receive shakes and shocks as it ascends, frees itself from the rocket, descends and hits the ground and then bounces around in its travels over uncertain terrain. How will it be secured?
Here is the photo Andrew kindly provided...
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Tracy Allen
www.emesystems.com
(Yes, I routinely fly electronics in high power rockets)
Post Edited (sylvie369) : 2/27/2008 10:35:50 AM GMT
·· Thanks for your post. There's not much room in the payload bay for a USB cable, nor much of anywhere else to mount the flash drive on the robot. We're using Public Missiles 4" diameter phenolic tubing and the robot is right at 4" wide...!
Any other suggestions on how to do it? What do you launch for rockets? How are you integrating electronics (and/or a Parallax board)? It seems fairly·straightforward to make a dual deployment system using Parallax accelerometers (though it would be bigger than a PerfectFlite, Black Sky Altcc, etc.)
Regards from NH,
Mark (and the Rocketeers)
www.cyberguys.com/templates/SearchDetail.asp?productID=4632
It should easily fit in your tight space and do the job. Only $2.60
phil
Post Edited (phil kenny) : 2/28/2008 5:56:22 AM GMT
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"A complex design is the sign of an inferior designer." - Jamie Hyneman, Myth Buster
DGSwaner
I'd think that you could plug an extension cable into the USB port where you currently have the thumb drive, then put the thumb drive into the other end, curl it over into that space above the robot and below the green cables (wires?) you're using to hold the robot under the parachute and attach it there.
Are you detaching the parachute somehow after landing? Or are you expecting to drag it along behind the robot? If so, you'd better have some extra kind of wire to make sure that the robot is pointing away from the parachute when you land. You know that the robot will land first, and the parachute will continue downwind until it has draped over whatever is there.
I haven't flown a Stamp yet, but I'm working on telemetry using a Stamp and XBee modules. I did fly a much larger device last year, a Vernier Labpro with a 25G accelerometer and a rapid response external temperature probe. It worked great, but was WAY larger and heavier than·it needed to be. I got the idea from the University School of Milwaukee SLI team, who I flew with regularly over the last few years.
I'm on my second year of Special Initiatives Grants from the Space Grant Consortium. Last year was the data recording project. This year we're doing radio tracking using a Big Red Bee, and since last Saturday we completed what I promised to do with that, we're moving on to transmit GPS location to a 2-meter handheld Kenwood on the ground. Hopefully that will fly in late April.
You might be interested to know that this year's Space Grant Consortium contest requires teams to do something that resembles what you're doing:
http://people.msoe.edu/~farroww/WSGC_rocket_comp/Rocket_Competition_08_params_rev2007-11-07.pdf
I hope to see what they come up with when they fly in early May. These contests are always interesting. I had a team last year and the year before. We won $500 two years ago for a rocket that deployed parachutes by radio control. Last year we crashed and took dead last.
Post Edited (sylvie369) : 2/27/2008 6:53:59 PM GMT
-Phil
·Sounds like you're quite the rocketeer too. Where do you launch (we're in New Hampshire.) Yes, it's essentially a piston ejection system. The piston mounts 'upside down' in the payload bay (bulkhead end down) and the robot rides inside of it. At ejection: "Pop goes the weasel! (or the robot, in this case.)
The Space Consortium challenge looks real interesting. I'd love to sink my teeth into it, but I mentor three rocket teams already (two TARC and one NASA-SLI team.) I'm also a Boy Scout leader and a science teacher (if you hadn't figured.)
Thanks for your reply. And be sure to check our project out at www.wearerocketry.org ('Weare' is the name of our town--sort of a double entendre, n'est-ce pas?) "Weare rocketry ... we are rocketry...!)
Regards,
Mark
"I have a 4" USB cable I'll donate to the cause. PM me your address if interested."
I don't know what PM means, but "We're interested!"····
Thanks and regards,
L. Mark Kibler
8 Ray Road
Dunbarton, NH 03046
mkibler@unity.edu
Look at the top of the forum web page (this one is fine), and you will see the following buttons:
LOG OFF | CONTROL PANEL | PRIVATE MESSAGE on the left-hand side
The "private message" is what we mean by PM. Now you can go check how may PM's there are waiting for you that have never been answered
Regards,
Bruce Bates
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"Genius is one percent inspiration and ninety-nine percent perspiration."
Thomas Alva Edison
Oh, PM as in 'Private Messaging' (duh!) I was thinking 'AM vs. PM' as in, "I'll e-mail you in the AM." I takes a rocket scientist, I suppose... I'll check the 'PM' section (this evening!)
Mark
What do you think of the following low profile, clear dome as a cover for the robot?
http://www.goldmine-elec-products.com/prodinfo.asp?number=G15775
Regards,
Bruce Bates
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"Genius is one percent inspiration and ninety-nine percent perspiration."
Thomas Alva Edison
···· Thanks for the link and the information. It looks interesting, and I like the idea of a see-through shell. Any idea what size it is or how flat it is. Is the diameter large enough that we could cut a 2" x 4" rectangle out of it? Recall that the robot is rectangular: it'd be like putting a square peg in a round hole.
The only idea· ·
Regards,
Mark
I guess you didn't click on the catalog number or the picture. If you had, you'd have seen the detailed description, which follows:
"Giant crystal low profile clear dome is 3.6" in diameter and about .35" high in the center. Made of heavy duty acrylic plastic. Great for robots."
I doubt you'll have much success cutting it, but why not mount it with short hex stand-offs? Take a look at the ones in the link below. You could stack them if you wanted to make them higher, to fit this round hole just above your square peg
http://www.goldmine-elec-products.com/prodinfo.asp?number=G14946
In browsing the Electronic Goldmine, I ran across a rather interesting, lever/pressure switch with a "large metal lever". I wonder if it could be adapted to replace the dowel-in-the-jack method of applying power to the robot. It has SPDT (single pole double throw) contacts so it can be used as a normally open or normally closed switch. The only issue with it might be contact bounce and that can be dealt with in the Rocket Robot Program. Here is a link to the switch:
http://www.goldmine-elec-products.com/prodinfo.asp?number=G16647
You will probably have to meet minimum billing requirements, so these items may help a little.
Don't drop that crystal on a rug, you'll never find it again! If you need help wiring it, just give a shout. I'm sure there are plenty of volunteers here to assist you with that task.
Regards,
Bruce Bates
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"Genius is one percent inspiration and ninety-nine percent perspiration."
Thomas Alva Edison
-Phil
Be sure you have the Parallax application notes for the DS1302, from this link: =http://www.parallax.com/Portals/0/Downloads/docs/prod/appkit/ds1302Rtc.pdf.
Yes, the tiny crystal has me a bit worried for your project. It works best if its two electrical wires can be soldered directly to the two pins X1 and X2 of the DS1302 chip. I will send you a photo of how that looks. The crystal itself is held with foam tape or rubbery glue on top of the DS1302. Not plugged into the white plugboard. There are several reasons, both mechanical and electrical, for doing it that way.
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Tracy Allen
www.emesystems.com
··· Thanks for the suggestion that we solder the crystal directly to the RTC chip. That is what you meant, yes? It's so small that I'm afraid to sneeze around it for fear that we'll lose it! I'm downloading the Parallax application notes as we 'speak'; I'll read them and get back to everyone (*they failed to download, three times.)
Andrew researched·the wiring schematic·before the parts·arrived and·forwarded a nice, detailed schematic of the wiring.·I connected the wires temporarily just before bedtime last night and did get a readout of 0:00:00:00:00 (or something like that.) We also located some preliminary program code to start with. Do you have any suggestions on where to browse for other code for the RTC. Are there are any important 'do's and dont's' we should know about so we don't fry anything?
Good morning,
Mark
·· Thanks for the post.·I guess I didn't go deep enough into the link you posted·to get the dome's dimensions···
We can definitely use your help wiring and programming the RTC. We only have a handful of Sunday practices left before we make our Flight Readiness Review video teleconference (and report) with NASA on March 31st. So we·really need to be (for all intents and purposes) "flight ready." We can do some last minute fine-tuning as needed after the teleconference, but these first few weeks of March·are·'crunch time' for sure.·Then, three weeks later, we launch!
We go back to school on Monday (we've had this week off for 'February vacation') and I'll try to keep up with everyone's posts. As always, I certainly appreciate your time and expertise······
Good morning,
Mark
OK, I finally got the Parallax application notes for the DS1302 downloaded and printed. Is there a simple sample program we should start with just to get the RTC to read out? Attached as a file is one of three I found last night. It seems to be for a stamp other than the BS2 because the LOOP sequence does not use a DO ---> LOOP command.
Mark
I notice there is only one Comment within the code section of the program. That might suggest to you how not to write your own programs.
If you want to figure out what that program is trying to do, you might go through the code, adding comments in all sections of the code.
PAR
· Thanks for the links to the acrylic domes! Who would have thought that there were so many different sizes and types available? Any idea where we can get a 2" x 4" (approx.) rectangular 'dome'?
Regards,
Mark and the Rocketeers
I don't recall if you ever said anything about having a soldering iron or any equipment of that sort. But I think this is pretty important.
Note also that the ends of the leads of pins 2 and 3 are chopped off. That is on purpose. They only want to be electrically connected to the crystal, NOT plugged into the white proto-board socket. The reason is that the protoboard socket has "parasitic" capacitance that can prevent the crystal from oscillating as it should.
Yes the Parallax application note is almost 10 years old and came out before the DO:LOOP syntax was included in the Stamp IDE. But it is meant for the BS2. That code can be simplified quite a bit as it has many bells and whistles you will not need.
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Tracy Allen
www.emesystems.com
·· So we should essentially attach the crystal to the top of the RTC chip (with epoxy,etc.) and then solder the two crystal wires 'down the side', onto the X1 and X2 ('middle') chip pins? I read in the tech specs that installing the crystal close to the chip, and not running the signal through wires, gives the chip greater time-keeping accuracy. Is that accurate?
Regards (I smell chicken for dinner!),··
(*the burger is faux chicken. Maybe it's a chicken burger...?)
Mark
······ Now·THAT was lightning-speed (300,000 km/sec.) response time...! Thanks for the details and jpegs.
Mark
Handle the assembly with care, i.e. let the team know that the crystal inside the tiny can is a delicate little tuning fork.
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Tracy Allen
www.emesystems.com
Post Edited (Tracy Allen) : 3/1/2008 11:28:13 PM GMT
·· Mark again. Looking down, bird's-eye view, which is the·'top' and 'bottom' of the RTC chip? The tech spec diagram·shows a small round dimple as the 'top', with the X1 and X2 pins on the left-hand side. The actual chip has a small round indentation on it's black 'surface. Is that the top 'dimple' (figure 1.0,·page·1·in the tech specs)? Does the crystal have polarity; does it matter which wire is soldered to which pin?
I bought a new soldering iron today,·one with·medium and small tips. (I should have bought a microscope, too...!) My old soldering iron has too large of a tip. Once I get the chip anc crystal soldered and installed, and once·we run the program, how do we get the RTC timer to 'run'? I had it wired just before bedtime last night and I did get it to output 00:00:00:00, etc. When the program is running, does it automatically start at 00:00:01 when the program boots?
How's the weather in California? You can't believe the snow we have here in NH!
Regards,
Mark
···· A telepathic forum; now doesn't that beat all. It must be a Zen thing. I can see the next best seller (telepathically, of course!): "Zen and the Art of Telepathic Programming". Who needs hardware...?
Mark
FLASH.... The RTC is working ....!· Tracy, the crystal mounted like a dream. Thanks for your photo. It was most helpful. I started a new thread "RTC_ROCKET_ROBOT" and attached the program that we're running·the RTC·on (I mean, on which the RTC is running. Pardon my sloppy grammar.)·I'll keep trying to post the wiring schematic as a JPEG; it wouldn't post the first time.
We have our first hurdle:·P0 and P1 are already being used by the humidity sensor, but the RTC also needs them... Is the fix as simple as putting both wires in both holes? See you at "RTC_ROCKET_ROBOT"
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Mark and the Rocketeers
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-Phil