On Sun, 25 Apr 2004 01:55:31 -0400, "Michael Simpson"
Looks nice, but if it were me I would want S1 to be spring return too.
The way you have it means that once the unit is armed, the relay is
under software control alone.
Also, how much current does it put through the igniters, while testing
Darren J Longhorn http://www.geocities.com/darrenlonghorn /
NSRG #005 http://www.northstarrocketry.org.uk /
Interesting, and very well documented.
With many igniters drawing more than 9amps for 2 seconds or more (there's a
plasma created when the thing goes off that keeps a 'short' circuit even
after the igniter has 'opened up') it seems like you might get a bad voltage
drop on VDD... which will reset your processor.
Seems like the batteries might be a pain to get to...
I would humbly suggest the following for "Launch Controller II"
1. Add a "Battery Test" indicator for the Internal Batteries.
2. Add battery charge circuitry for the internal batteries charge with
12vdc or a wall-wart.
3. Consider using an easily accessible External Battery(s) for the
4. Consider adding a "Battery Test" indicator for the External Battery(s).
(If you decide on a standard 9volt battery for the external igniter battery,
you could also test other rocketeers batteries before they attempt launch...
you'd become VERY popular!!!)
You might also consider using Li-Poly or Li-Ion battery's... no memory
problem, more available currant, more environmentally friendly, (and yeah,
much more expensive).
This launcher was designd for Small engines up to C size. We have yet to
have a problem. If you get a dead short and the power drops below 2.5v the
proccessor resets and kills the relay. A small routine at the keeps the
unit from arming againd if the button is still pressed,
Later I may build a launch unit that has small batt for logic controll and
larger battery for igniter but wont do it until I get my electroinc launch
pad finished. It's going to have servos for leveling and wind dir and speed
Speaking of BASIC Stamps...
Is anyone here doing anything rocketry related with stamps? I've
recently started playing with them and have a few ideas developing but
I'd like to hear what others have done (are doing) with them.
NAR #22012 Sr. L2
for email drop the planet
"X-ray-Delta-One, this is Mission Control, two-one-five-six, transmission
Very similar syntax. Much of it has been simplified. It not a stamp
clone. There are two chips The Dios which is the flagship. This chip was
developed for engineers and robotics tinkerers. It runs about 10 times
faster than the stamp and has floating point variables and strings. While
the language is Basic like the stamp its more like VB because you can have
functions and libraries.
The Athena was developed to get people started into microcontrollers. It
has the same kind of program model as the stamp but costs a lot less. The
compile is also free was designed for beginners as well,
We are releasing a new chip in the next month called the Perseus. This chip
is much like the Athena but has an 8 channel AtoD. It also has commands for
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