A Lurker Comes out...
gibbman
Posts: 98
Hello Forum members and guests,
I've been lurking for a while since experience has taught me that it's better to know how a forum runs than to jump right in. Thanks for having me, and thanks for the info already gleaned from the content.
I'm Jim, and live on the coast of NC. I teach electronics and computer-related courses at a community college.
One reason for my being here is I am now in the position of having to teach and develop student projects with microcontrollers. Parallax was kind enough to send two great instructors to my campus for a·Basic Stamp course for educators. Thanks, Ryan and Kris! It was very helpful.· Now, I need to develop a program for microcontrollers at the school, both curriculum and continuing education. I would like your advice on a couple of things:
Any advice is welcome, and thanks for having me in your well-run Forum.
Jim (aka gibbman)
I've been lurking for a while since experience has taught me that it's better to know how a forum runs than to jump right in. Thanks for having me, and thanks for the info already gleaned from the content.
I'm Jim, and live on the coast of NC. I teach electronics and computer-related courses at a community college.
One reason for my being here is I am now in the position of having to teach and develop student projects with microcontrollers. Parallax was kind enough to send two great instructors to my campus for a·Basic Stamp course for educators. Thanks, Ryan and Kris! It was very helpful.· Now, I need to develop a program for microcontrollers at the school, both curriculum and continuing education. I would like your advice on a couple of things:
- should I stay solely with the BS2 and PBasic, or move to the SX side of the house with SX/B? Costs are a real concern, and the SX48 board for $9.95 has a lot to recommend it.
- since eventually we will be working on the data-collection side for our marine science folks, such as some passive sensors, and relaying them via RF to passing small craft, is the SX more capable with it's larger array of I/O?
- will the availability of the coming C compiler for the SX make any difference?
- any ZigBee folks out there? (see bullet 2)
Any advice is welcome, and thanks for having me in your well-run Forum.
Jim (aka gibbman)
Comments
I think our customers (particularly those in education) should answer these questions, but I'd like to address a few of them. They'll always tell you something we don't know from working at Parallax.
Regarding your first bullet about costs - this won't be the case much longer. Very soon, the tools will become less expensive along with the chips. Having internalized the SX to Parallax (we manage the fabrication and packaging of the line) our costs have decreased. I expect some decrease in SX chip prices in January, even at low volumes (and particularly for the one you use - the DIP28). And, having the chips sold from our office gives us less reason to make profit on our tools. They should follow suit as well, but it will take a bit longer. We just finished an SX Blitz redesign (it's all USB now) and we're doing the same with the SX-Key. Getting these products back from a production line can take a lot of time, but by March we should have settled on a lower tool price.
As for the RF data collection aspect, the SX will enable you to sample more sensors faster, but the basic communication via RF would be similar to the way it's done with a BASIC Stamp. The additional I/Os will be helpful for connecting more devices, though.
The C compiler? The value of this remains to be seen, as you will notice from other threads. But, if you've used the BASIC Stamp why not use SX/B? I take it that the C language is part of your ABEC standards or some other professional requirement. Please confirm.
The ZigBee circuitry and code is far from trivial, as we've discovered with our wireless Board of Education R&D. There's a hefty license fee for ZigBee products. But I think your interest is in using an off-the-shelf ZigBee solution. In your applications, what benefits do you expect ZigBee to bring you beyond what you currently have with a simple serial RF link? It must be the parent-child bonding which allows data to be relayed among ZigBee clients, is it?
Hopefully John Couture will reply to your inquiry as well - he uses the SX in his classes in San Diego.
Welcome to the forum, by the way. Makes me wonder how many other customers lurk and never pose a question. You're not the only one - I've met many customers who say they love the forums but they've never posted a question or they're afraid of the answers they may receive.
Sincerely,
Ken Gracey
Parallax, Inc.
Since this is a college level course, I would definitely suggest using the SX. The BasicStamp is a great device, but the it still provides a lot of insulation from the actual CPU and what it's doing. I personally feel you'll be doing the students a great service by using the raw SX chip. As you point out, you can teach them programming initially using SX/B, but you'll also be able to see what's happening down at the register level.
In addition, for more advanced or agressive students, they can drop down into assembly programming either by itself or from within SX/B. The upcoming C compiler support will also give you another language to teach/use if so desired. No knock on the stamp, but I think the the raw SX has some serious advantages when it comes to a college level course.
Thanks, PeterM
Thanks for the responses! I'll cross-post this to the Educator's Forum and see what comes of it. As far as the Stamp vs. SX decision, I'm leaning toward the SX with SX/B at this point, especially considering the reductions in store, especially the dev tools. And to Peter's point, it will bring the students (and myself) closer to the microprocessor. I do hope that some will move to assembly if I can stimulate them to do so with some interesting projects. C has been pretty much dropped from the college curriculum in favor of C++, Java, and VB. A pity; it's also much closer to the machine.
The reason for considering ZigBee is that we hope to outfit some crab boats to do some data collection as they travel the sounds around here. Hopefully, we can develop a system where the boats will join the sensors in an ad hoc network as they pass. Once established, the sensors will dump their data to the boats, and the boats will dump their collected data at the dock. Will eventually hope to gather salinity, oxygen levels, pH, and water temps. Glad I don't have to buy the sensors! Again, this is down the road, we will start with temp and timestamp to prove the concept of the RF links. I'm looking especially at the Maxstream Xbee products, off-the-shelf and only needing interfacing. Power consumption will be an issue, as well as maintenance, since few folks like to go tromping around the marshes here during warm weather, due to the cottonmouths and rattlers.
Again, my thanks,
Jim
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http://metroidclassic.com
=========
DMCA Sucks
RIAA Sucks
Me, I'm stuck doing a 3mbps data link with SX's, and trying to pull errors out of analog electronics.
-Dan
·
Bean.
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"SX-Video·Module" Now available from Parallax for only $28.95
http://www.parallax.com/detail.asp?product_id=30012
"SX-Video OSD module" Now available from Parallax for only·$49.95
http://www.parallax.com/detail.asp?product_id=30015
Product web site: www.sxvm.com
Forget about the past, plan for the future, and live for today.
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Cheers,
Peter (pjv)
Steve
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"SX-Video·Module" Now available from Parallax for only $28.95
http://www.parallax.com/detail.asp?product_id=30012
"SX-Video OSD module" Now available from Parallax for only·$49.95
http://www.parallax.com/detail.asp?product_id=30015
Product web site: www.sxvm.com
Forget about the past, plan for the future, and live for today.
·
I get the project because I'm writing it, and hoping to get it funded (got a little seed corn to start).
I'm sure the IT work with SQLServer pays way better than community college wages.
Bean, we had cesiums back in the day when I worked for NATO at a satcom site. Do your OCXOs use ovens to maintain stability, or are they really that stable uncovered? Thanks for all the input and discussion,
Jim
I can't believe for one second that a reasonably regular GPS receivers will provide THAT level of time precision. Some very specialized ones such as used for suveying, and then referenced differentially....possibly, but certainly not the "run of the mill"; even the "better" run of the mill.
One pico second?.....NO WAY! In fact, I would not even believe one nano second.
Cheers,
Peter (pjv)
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"OEM NMEA GPS Module" Now available on ebay for only $19.99, FREE shipping until 2006!
Product web site: http://www.allsurplus.net/Axiom/
<pounds head against wall>
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---
James Newton, Host of SXList.com
james at sxlist,com 1-619-652-0593 fax:1-208-279-8767
SX FAQ / Code / Tutorials / Documentation:
http://www.sxlist.com Pick faster!
The GPS 1pps has alot of jitter, but by averaging over a very long time (256 seconds or longer), the jitter can be "smoothed out".
We actually had plans to make this type of oscillator several years ago, but it got put on the back burner.
But we're really getting off the subject here...
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"SX-Video·Module" Now available from Parallax for only $28.95
http://www.parallax.com/detail.asp?product_id=30012
"SX-Video OSD module" Now available from Parallax for only·$49.95
http://www.parallax.com/detail.asp?product_id=30015
Product web site: www.sxvm.com
Forget about the past, plan for the future, and live for today.
·
The headline specs are:
• Less Than 40 Nanoseconds rms Accuracy to UTC
• Less Than 1 x 10-12 Frequency Accuracy
• User-Configurable Outputs
Short-term stability isn't so stunning, though -
Accuracy: 1x10-12 when tracking satellites
Stability: 1x10-9 at 1 second <-this is generally good enough for my needs - and then some.
3x10-10 at 100 seconds
1x10-12 at one day
Stability when not tracking satellites: 2x10-6 over 0° C to +50° C
Still, it's kind of nice to be able to tell the time accurate to 40nS, especially when someone else is paying for the tricky bits...
Steve