[islandlabs] Balloon Cameras Info

Joe toolfox at gmail.com
Fri Mar 11 02:41:52 UTC 2011

On Mon, 7 Mar 2011 21:38:48 -0600
Joe <toolfox at gmail.com> wrote:

> It looks like I need to wire up the second camera for remote control
> and rig both cameras for external supplemental power. 

Both cameras are currently wired for remote control. No external power
is wired as yet

> What do we have around in terms of small connectors that can be
> soldered to a prototype board and take 30-gauge wires?

Well, I found some connectors at work that, with a bit of whittling
with an Xacto knife, will do the job.

> At what supply level does the ATTiny brownout?

I found the datasheet for the ATTiny 45; 2.7 volts is the lowest for
higher clock speeds. We can decrease that to 1.8 volts if we drop the
clock lower. Both voltages are far below the point where the cameras
will shut down.

> These are some of the ground tests we need to start performing before
> we can declare the system flight-ready.

Bill, we need to get together and complete the camera software so we
can start ground testing for longevity of operation, low-temperature
operation, and a combination of the two. I'm spoken for tomorrow and
Saturday; Sunday will be my first possible open day/evening.

In terms of hardware, I see the Atmel chip running directly off the
camera's external battery pack; I'm going to connect that pack to the
PC board for power distribution to the two cameras. A dropping diode
will be in series with each camera power feed so we don't roast the
internal battery. There will also be pins for the various connectors.

I can build this protoboard; I have the skills and have done so many
times in the past, so that's not a problem. What we need is the
software, which I think is the second-to-last bottleneck to an APRS

I'm still waiting for the flight radio, which could be arriving within
the next few business days...maybe a week at most?

We'll also need a new balloon. When I weighed the components of the
APRS system two weeks ago, I came up with about 590 grams. I should do
a new weigh-in with the newest revisions and additions (cameras,
photography bay, battery pack) and get weights for the TinCan itself
and the parachute.

"TinCan" is the new nickname for our payload container: A Direct
Descendant of TunaCan.

Which is not to say that TunaCan won't fly in a future mission...


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