SCAT Electronic News 6 October 1999
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SCAT Electronic News 6 October 1999
"SCAT - 40 Year's of FAI Free Flight Competition"
Table of Contents
=================
Editorial appology
Microcontrollers
Palm Pilot News
Free RCDT design? And DIY electronic timers - Jensen
Chill Out Chuck, RCDT is not all black & white! - Davis
Editorial appology
==================
I seem to be doing this too much lately - but the funny
attachment in the last message was the plan of Bauer's XXD/T,
encrypted so the "againsts" could not see it - but rather
one of correspondent's logo that MS outlook had attached
to the message he sent me - and I overlooked and
did not strip it from the newsletter.
microcontrollers
================
Klaus Salzer is correct in that the advent of the microcontroller
has made the construction of an electronic timer much easier.
It really a computer programming task rather than pure
electronics design and it sounds from Klaus's other mail
that he is familar with computers. Be aware that
writing a program for an embedded system like this is
not always an easy task. A reason why I do not publish
any source code is because I'm not prepared to spend time
helping other modellers write programs. I've spent too
much time professionaly managing/teaching bad programmers
[none of the people who currently work for me. of course !]
to want to do it for fun! ... and I would never get any
motors done then. Like Torlief below most of my programming
is done in C.
It's fairly easy to program a timer for oneself but much harder
to do a commerical product that has to be 'easy to use'. As I mentioned
before there are a number people such as Jim Parker who
have been very sucessful in programming their own timers.
It's rather like building any aspect of your model. If
you can build it well it is an advantage because you get
it exactly the way you want. If you cannot do it then you can be
in deep trouble.
One of the most difficult parts of any of the commerial
electronic timers is the method of setting your flight times.
For the timer to be easy to use by a wide cross
section of the modelling community this has to be fairly
simple. There are a number of different approaches -
separate programmer box, program on a PC, program on a
HP hand held, program on a PalmPilot or a Casio organizer.
The programming of any user interface is a non
trivial matter, everyone is an expert and has their own
opinion. If you make your own timer you can make short cuts
in this area as the only person you have to satisfy is yourself.
The Stamp makes it easy because there some electronic
[inspite of what Klaus says!] aspects to
be taken care of .. and the Stamp does that. Parallax
have introduced more models, including the Stamp on Steroids,
the latter is very fast but has a much higher current draw.
There are some issues where people who use the Stamp differ
in approach/opinion. For example in Allard van Wallene's article
in the 1999 NFFS Symposium be uses an extra crystal to provide
the clock, not trusting the Stamp's Ceramic Resonator, while
other user's are quite happy with the Ceramic Resonator.
Incidently Allard's article does include the BASIC source
code for his timer. In looking at the program you will
see some instructions that you might think are not
necessary - I suspect that Allard had to put these
in to deal with some quirks of the Stamp. He probably
found them to be necessary over a prolonged testing
period.
For the BlackMagic timers I use some chips of the PIC family
in their native mode. PIC Micro controllers
form the basis of the original Stamp and the Stamp 2.
Microchip, the company that makes the PIC family
has risen from being the 6th largest 8 bit microcontroller
maker just a few years ago to the second position.
The PIC is very suited to our applications as it is both
physically and electrically robust.
There are other good choices of8-bit microcontrollers Intel,
Motorola, Zilog, National,...
Palm Pilot News
===============
3-Com have announced 3 new models
*PALM Vx(TM) ORGANIZER*
*PALM IIIe(TM) ORGANIZER SPECIAL EDITION*
*PALM VII(TM) ORGANIZER*
The Palm IIIe special edition is the new bottom of the line model,
it has the better screen of the IIIx and IIIe with less memory
an a lower price.
This was probably launched to combat the about-to-appear
Visor. The Visor is PP compatible and comes from a new
company founded by the original creators of the Palm Pilot.
The Visor should appear "real soon now". All of this
should help the Black Magic timer user by driving down
the prices of the PalmPilot.
Free RCDT design? And DIY electronic timers
===========================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Hi all.
Just a few comments to the somewhat emotional RCDT discussion.
I agree with Ken, RCDT should be kept in F1C for security reasons. There
has been lots of dangerous events that could have been avoided. The
worst in Denmark so far is a woman that was hit in the head by a F1C
model.
Although in favor of RCDT, I share the resistance against any other uses
of RC than TERMINATION of the flight.
Since I originally posted my opinion on the subject and suggested an
implementation, I have had a few requests for an add-on for mechanical
timers or for other brands of electronic timers. I have problems enough
keeping up with my timer deliveries, so I can't offer to sell this
product.
I might find time to do a free design, that will be posted on my
homepage, if there is a general interest for it. It will consist of a
small microprocessor board at each end and some C code in source and
compiled format. I will not do the assembly, but I might be willing to
supply preprogrammed microprocessors.
For electronic timers, it could be fitted between the timer and the
servo and for mechanical timers, it would require a servo and a battery.
Would there be general interest in such a design? Or would a set of
design guidelines do?
Then a comment to Klaus regarding DIY electronic timers: If you like the
challenge, do it, it can be done. Be aware that there is a lot of
experience to be gathered, I think you'll revise your attitude (at lease
if you build a F1C timer). And by the way, lots of people are selling
timers at close to the cost, so why not just buy one of those and then
build models instead?
Thermals,
Torleif.
Chill Out Chuck, RCDT is not all black & white!
===============================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Adding more fuel to the RCDT fire I feel that the addition of the RCDT
function to a timer is not all that big a deal and makes sense for a
number of reasons. Those who want to remain pure and untainted by the RC
curse can simply not push the button if they want a pure "free flight"
experience. While I like the ability to DT the model in order to save
some chasing and cut the risk of losing the model one of the most
compelling arguments for using it is in trimming models and in
preventing catastrophic crashes where much time and money goes up in one
big cloud of dust, carbon fiber shreds and balsa splinters.
Regarding the purity of chasing models on foot at contests with rounds I
find it just about as pleasant as having splinters pushed up underneath
my fingernails. Sure, we have all had that wonderful high experience of
walking back with our model after the last round, the air is dead clam,
the sunset beautiful, the flight so perfect that we feel on top of the
world, a day well done and the glow of that self righteousness that we
free flighters feel in knowing that we are the "pure" model flyers,
ahhh, a perfect moment in time. I've had that experience too! For every
one time I felt like that I've had ten where the chase was done in high
winds, there is 10 minutes before the next round starts, I've just spent
15 minutes running around in circles trying to find lift, I've hit two
gopher holes, slipped on one slimy busted F1B motor, got poked in the
eye from my walston antenna as I was getting out of the gopher hole, and
then had to run for two miles in 95 degree heat. There are times that a
"good healthy chase" in these conditions is just about as pleasant as
pushing your car to the gas station when you run out of gas and your in
a polyester suit with a real tight neck tie. If you enjoyed boot camp
you'll love chasing models on foot! Have any of you had the experience
of offering your chase bike to a fellow modeler on a contest flight and
having them answered " oh, no thanks, I much prefer to run my guts out
and hyperventilate while I chase my model on foot, that way I can feel
good and delusional by the time the fly-off starts"? As a modeler who
has to travel to contests and can't get his dirt bike to fit in the
overhead luggage bin there is no question that the locals who have chase
bike have a huge advantage. Take a poll, what percentage of modeler's
who fly at Lost Hills use chase bikes if they live within driving
distance of the field? I'll speculate that it's 90% or more. In my
opinion the noisy din of dirt bike engines and exhaust is a lot less
"pure" than RCDT. Try to outlaw chase bikes and see how far you get,
competition free flight would die a quick death! To level the playing
I'm considering a rent-a-kangaroo (rent-a-roo as the Aussies say) for
the next world champs. They don't need gas (they make their own) no one
will ever ask you to borrow it to chase their model, and they can can be
quite smart when you get to know them. The downside of course is the
occasional punch in the face from the roo and a tendency to step on the
models (and us to step in the Roo Doo) but even that beats chasing on
foot.
At the latest Nats I recall during one of the longer chases I had on the
first day, (when it was still hotter than hell and humid as a swamp and
I was about to go into heat stroke) that chasing on foot in those
conditions was about as close to suffering as anything I had ever
voluntarily done in my life. I much prefer a "modest" chase in free
flight. I'm for RCDT so that I can have some choice in the matter. I
might very well choose to cut a flight short and lose a contest (not
that I ever win any) rather than lose a model or spend my day plowing
through cornfields looking for a model. The pros of RCDT far outweigh
the cons and it doesn't debase the purity of our sport and hobby anymore
than a bra debases the natural shape of a woman's body (crummy analogy
but I couldn't think of anything else). Let's get some prototype
systems in place and experiment with them and see what happens. As one
of the e-mails on this topic pointed out the logical place to
incorporate the RCDT is into the existing electronic timers (go Roger,
go!) It's not a big technical leap to give it a good try. I volunteer to
try it in my models, I've had enough boot camp!
One last thought on how to make changing the rules easier, how about
this! Let's go to cafeteria style rules, you can have a chase bike or
RCDT but not both, or you can have bicycle and walston retrieval system
but not RCDT, or you can have all three but you can't look at the model
until it is on the ground, or you can have a purchased model with full
RC control but none of your scores count. I am amazing, what a fountain
of prolific and creative ideas. I need to stop now before I overwhelm
myself with my genius. See you at the Livotto contest , and by the
way........... can I borrow your chase bike?
Mac the Bigot
This email address is being protected from spambots. You need JavaScript enabled to view it.
[ Sure Jon, which bike do you want - The 180cc rocket that can get
you in big trouble or the 70cc CT70 - or I still have that FatCat
for sale.. But I'm not sure if I can loan one to Evan, he is getting too good
and too much competition for us old F1B flyers -Also get up with Ken Bauer
and me, you never know what we might be able organize on the Timer and D/T]
......................
Roger Morrell
