David is this possibly a XBEE module? The XBEE modules could
accomplish exactly what Richard's dream system would need. I have some
experience with these too. Richard Dierking I can put together a
couple of concepts both "dream system" and "partial dream system" The
biggest problem I see would be batteries(one per pad). I won't be at
ROCtober but will be at ROCstock.
Richard C. Hall
TRA 11515
-----Original Message-----
From: David Erbas-White
Sent: Oct 7, 2012 7:14 PM
To: roc-chat@xxxxxxxxxxxxx
Subject: [roc-chat] Re: ROC Launch Control System
On 10/7/2012 6:03 PM, Richard Dierking wrote:
In my 'real life' job I'm working with some wireless systems
(actually, using a wireless module with our own proprietary
control circuitry -- but as the module is FCC approved, don't need
to worry about that end of it). I have tested this system on the
lakebed to over a mile, reliably. If we were to come up with some
definitions of exactly such a 'wireless dream system' were to do,
I could perhaps cobble something up that would be extensible.
Effectively, the system I'm working with is a single-master,
multiple-slave system, which would be ideal for what we're doing.
To avoid interference from other sources, we would have to use
secure encoding, along with timing, to ensure safety (i.e., a
secure code to arm the system, system disarms if it either times
out or loses signal from the master, etc.).
If we design a modular system (i.e., a relay box with batteries
for doing the actual firing, and a 'receiver section' that handles
the wireless and intelligence, we should be good to go. Current
systems (as I envision them using these components) would require
a PC to act as the launch controller. If we really wanted to, we
could simply build a wireless box that 'looks' like the current
launch controller, but sends the proper signals via the wireless
master -- but I'm just kind of thinking out loud...
What might be the more difficult aspect (possibly) would be the
continuity detection (wirelessly), as we would need to have the
circuitry in the range-head box to 'tell' the wireless unit if
continuity was present, etc. And this circuitry would need to
work in conjunction with the current system of the
push-button/buzzer for the pad area itself. We'd also need to
ensure that we can handle the wider-range of igniter firing levels
(like the new Quest igniters) with such a system..
Love to hear what other folks might think...
David Erbas-White
*Wireless System:*
These types of systems (particularly multi pad systems) are just
being developed and there's not a lot of experience using them.
If we had to obtain a new system today, I would suggest a
wireless system because of the savings on the weight and cable
cost. But we don't need a new system currently, so let's see
what's developed over the next couple of years and listen to
their experiences. In the meantime, we can save for a system so
when ROC's ready, we'll have the money for a safe and reliable
system.
For me, my 'dream system' would look something like this: A
small control box would be located at each launch pad that would
be the receiver for a computer based wireless system. The LCO
would launch rockets using a computer and daylight monitor
connected to a powerful (over 2,500' range) wireless transmitter.
The pad control box would have a shunt and power switch
controlled by the person loading the rocket and be located on a
ground stake that would also have the pad number sign. There
would be both audible and visual arm signal on the box and it
would also have a connection for a larger battery if necessary
(i.e. more firing amps). So, no central control boxes, just
place the launch control box with the pad number sign were you
want a pad, attach the launch leads with clips, and away you go.
This would allow for any kind of spacing on rows.
Richard Dierking
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