JOURACA_SP_2017

Software Infrastructure
for Cubesat
Brent Greenwald
This paper describes the development of the
Command & Data Handling System
(C&DH) for the "JAGSAT-1", a CubeSat
created by the CubeSat Team at the University
of South Alabama. The C&DH is designed
to receive status messages from other
components of the CubeSat, receive commands
and code updates from ground control,
and issue commands to components of
the CubeSat in order to carry out the scientific
mission and perform important housekeeping
functions. Using a "software ecosystem,"
which is being developed to enable
multiple microprocessors to connect and
communicate with each other each other,
the C&DH will receive events, interpret
them, then generate commands to issue back
with the use of real-time queuing. Our team
is creating a probe for measuring the frequency-dependent
behavior of ionic plasma
in the magnetosphere. The team successfully
launched its first prototype in a suborbital
mission in March 2016, and is still analyzing
the data from the launch. Now moving
on to stage two, we plan to create a complete
satellite (called a "Cubesat") that will
orbit the planet collecting measurements
that we will receive throughout the mission's
life span. The first step was to purchase
two "Tower" development systems
for the microprocessor that has been selected
for most of the CubeSat boards. The
processor is an NXP Kinetis processor,
Department of Electrical and
Computer Engineering
Electrical and
Computer Engineering
Mentor: Dr. Samuel Russ
which features low power consumption and
a usable software development environment.
After learning to use the environment,
a simple "hello world" program was
developed and tested using PuTTY (a serialport
debugger). The next step was to get two
development systems to communicate over
a CAN interface. This was accomplished
by, first, configuring the Kinetis processors
to enable CAN pins for transmitting and
receiving and, second, sending and receiving
messages over CAN. In conclusion, we
have developed a software environment for
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