Hi all -
I'm making my own ematches with about 6 wraps of 40ga nichrome around
some scrap cat5 pairs, soldered. The primary pyrogen is dark flash,
secondary is Shimizu's H3 with a final coat of NC lacquer. The
resistance is around 8 ohms nominal. My first attempts at firing these
with the telemetrum were a complete failure. The LiPo battery fired
them just fine but the altimeter didn't. So I went digging.
I built the tool chain under Gentoo x86 and grabbed the sources from the
latest 1/19/11 git snapshot. The sdcc sources did require patching to
compile with gcc4.4.4 on my system.
ao_ignite.c has the define:
#define AO_IGNITER_FIRE_TIME AO_MS_TO_TICKS(50)
There's no way that my ematches will fire in 50ms. I've redeclared it
to:
#define AO_IGNITER_FIRE_TIME AO_MS_TO_TICKS(2000)
While it only takes perhaps 150ms to fire, I figured 2000ms would
definitely do the trick. I flashed my device and that value seems to
work fine.
Does anyone see any unknown side effects to this change? Aside from
this file, I haven't looked much further into the code.
What would be very nice is to allow this value to be specified as a
parameter in a setup menu. I may look into adding that code if any one
is interested.
Also, before making the change, I compiled the firmware and compared it
to the distributed versions. They don't match. Any ideas why?
Perhaps I grabbed the wrong snapshot?
Thanks!
--
~Don
------------
Hi folks,
I finally got my Ham license last weekend, mostly so I can fly a Telemetrum.
Although I studied the licensing manuals, they didn't imbue me with much
practical understanding of antennas. Indeed, they just made me realize how
little I actually understand about RF, so I'd appreciate some advice.
I'm planning to put a Telemetrum in the fiberglass avionics bay of a
Performance Rocketry Little Dog Dual Deploy, but the bay is only 7" long,
which poses a packing issue with regards to fully extending the Telemetrum's
~7" UHF wire antenna.
My first thought was to just mount the Telemetrum on a plate towards the
forward end of the bay, then bend the antenna back 180 degrees to the other
side of the plate and run it back the length of the bay. However, I'd
prefer to mount the telemetrum further back in the bay.
My second thought was to mount the SMA version of the Telemetrum (which
seems like it might be beneficial in other rockets anyhow) in the back of
the bay, then run a short piece of coax to the front, bend the coax back,
and connect an antenna there. In this case, I could buy a pre-built SMA
wire antenna (BigRedBee, $6), but I'm also wondering if I could simply strip
the last 7" of shielding off the piece of coax and let the center conductor
radiate through the dielectric.
Any thoughts?
Thanks,
Casey Barker
AG6CE
I had my first and last flight with this system yesterday. I got a GPS
posn for the launch pad, but no data during the flight or landing. The
ex motor I mixed burned great, very fast lift off, then never to be seen
again. I believe it came in ballistic and was never found, visually or
with GPS. Its buried somewhere in a cow pasture. Maybe I can find it
next month.
Bruce
---------- Forwarded message ----------
From: w9ya <w9ya(a)qrparci.net>
Date: Mon, Feb 21, 2011 at 5:17 PM
Subject: Re: [altusmetrum] TeleMetrum and Giant Leap's Mariah-38
To: Bdale Garbee <bdale(a)gag.com>
Dunno anything more specific *Bdale *other than the thickness of the sled
and the standoffs necessary to allow the usb and so forth to clear the sled
(with some additional margin of "safety" added in) seems sufficient. I
lucked into a 'good enuf' clearance just doing the mounting as I would do
normally.
More specifically my notes are too meager to know exactly what was at
issue.....or I cannot find anything more specific in my notes at this time.
Sigh.
On a cool note .... I just snagged C6AKQ on 14.0225 MC with 4 watts !! ....
Made my afternoon.
Vy 72 de;
- Bob F.
(w9ya)
P.S.... There might be something more specific if'n you have an irc "dump"
and you care to peruse it for any info I might have spouted out when I was
doing the 'flight' testing ala my brake-bleeder/altitude chamber goodie.
On Mon, Feb 21, 2011 at 4:46 PM, Bdale Garbee <bdale(a)gag.com> wrote:
> On Mon, 21 Feb 2011 16:38:08 -0700, w9ya <w9ya(a)qrparci.net> wrote:
> > One thing I have noticed with my v1.0 tm .... the battery cannot be
> located
> > immediately against the tm. I had to space mine away form the tm a bit to
> > avoid "issues" with operation. I discovered this when placing the battery
> > and the tm into my "altitude chamber" for some testing last summer. The
> > chamber is awfully small but this turned into a blessing as I discovered
> > this operational constraint.
>
> That's .. interesting. Any idea what the actual problem was? I've had
> batteries all around boards in fairly close proximity without seeing any
> problems on the bench, and I recently put them just on the other side of
> the sled from the board. Very curious what the mechanism might be, here!
>
> Bdale
>
I just got the Telemetrum starter kit from Apogee and now trying to get
it to run. I am unclear on how/where to install the Linux packages. I am
running Kunbutu 10.10. I tried the Debian install, but got an errors:
demigod@Behemoth:~$ sudo apt-get install altos
[sudo] password for demigod:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
altos : Depends: freetts but it is not installable
E: Broken packages
So I got
http://www.altusmetrum.org/AltOS/releases/0.9/Altos-Linux-0.9.tar.bz2
I unpacked and left in my home directory, limited luck, the moved it to
root.
ao-list does not work. Sound does not work. I get limited and unreliable
connectivity between TeleMetrum and TeleDongle.
I am use to apt-get and installing from source, ./configure, make make
install. But this install has me baffled.
Thanks
Bruce
