times and they always work well.
Next, power-up the board and watch the four
indicator LEDs. All will be on for a second test, with a
double chirp from the piezo buzzer. They will all be off.
The green heartbeat LED (labelled HB) should begin
pulsing with a two second period, indicating the program
is running. The red SD LED will come on briefly, then
quickly go off if the SD card is mounted successfully.
The red FXQ LED will be on for a minute or so while
the controller is acquiring contact with GPS satellites. It
will go off after four or more satellites are acquired. It
may blink on and off several times if you are in an area
with a limited sky view.
The red MBX LED will initially be on. After the
satellites are acquired, it will stay on if you are outside the
mission box, or go off if inside.
The red LED next to the big cutter relay should be
off. If it is on, watch out! There is a problem. That means
the real contact is closed and power
is being sent to the nichrome cutter.
If so, there will also be an audible
warning from the piezo buzzer.
Be sure to delete all of the files
on the SD card before each flight. A
new file is created — to a maximum
of 99 — every time you boot-up the
controller. This can happen quickly if
you do a lot of pre-flight testing. The
controller will freeze when the file
limit is reached.
The serial terminal is a
convenient way to evaluate pre-flight
sensor and program performance.
Simply start the Parallax Serial
Terminal quickly after the controller
is started. Sensor data and program
function information will be
The original goal for the 2013
mission was to capture an image of
the aurora borealis from 100,000
feet. Although that was not
successful, the project was successful
in many other ways. We all learned a
lot, and for several students the
project motivated changes in college
and career plans.
I would enjoy hearing from you if
you decide to build and launch one
of these. Please send your thoughts
to me at rlevergood@london
22 July 2017
Project SMART is a month
long summer program for talented
incoming junior and senior high
school students (visit http://project
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