Electrical and software subsystems

CubETH is now at the end of its phase B development, which means that the satellite Electrical Model shall validate the majority of embedded functionalities. During the past semesters, the electrical subsystems were independently implemented by the students, based mainly on the SwissCube heritage.

Most recently, master student Adrien Corne could combine all subsystems together and validate inter-board communication capabilities. As seen in the diagram below, the Electronic Model architecture embeds most of the subsystems.

 

Block diagram of CubETH electrical subsystem

 

 

 

Subsystem Abbreviation Description
CubETH electrical subsystems
Attitude Determination and Control System ADCS Sensor fusion between accelerometers, magnetometers and sun sensors. Control driving electronics for magnetic control.
Battery Board BB Contains the batteries necessary to power the satellite during eclipse, as well as thermal control and unlocking electronics.
Command and Data Management System CDMS On-board computer. Data centralization, processing and storage.
Communication System COM Radio link with ground station. RF electronics for modulation and decoding. Llinked to the satellite antennas.
Electrical Power System EPS Power generation and management system. Batteries control. Sensor to monitor voltage, current and temperature for every solar panel.  Power distribution unit.

 

The CDMS is linked via UART to a computer to facilitate debugging and data gathering. The figure below shows the setup. A standard 104-pin interface exists on each board so they may be plugged to a FlatSat platform.

 

Optical photo of CubETH flatsat

 

The inter-board communication protocol is I2C. The CDMS acts as master and requests flight data from the other subsystems. At this stage of the development, relevant data to gather is typically housekeeping parameters, as board current consumption, temperature, status flags, or battery voltage. Such data acquisition and I2C communication were implemented on all present subsystems.

 

Past students projects on CubETH electrical subsystem

Recent Master thesis

  • Spring 2015, Adrien Corne, CubETH Electronic Model Upgrade

 

Recent Semester projects

  • Spring 2015, Daria Stepanova, CubETH communication drivers implementation
  • Spring 2015, Lianel Pierre Etienne, Housekeeping data generation and transmission from COM subsystem to CDMS
  • Fall 2014, Nawaaz Gujja Shaik, Software driver for ADCS peripherals
  • Fall 2014, Adrien Corne, CDMS board hardware iteration
  • Fall 2014, Jean-Noël Pittet, CubETH flight software
  • Fall 2014, Jérôme Amiguet, CubETH B-dot Controller Implementation
  • Fall 2014, Marcel Starein, Thermal characterization for pico-satellites attitude determination sensors
  • Fall 2014, Raphaël Valceschini, Analog sun sensors tests characterizations for picosatellites
  • Fall 2014, Valentin Richoz, CubETH: Communication Board Software
  • Fall 2014, Mathieu Bresciani, Software for CubETH
  • Fall 2014, Lianel Pierre Etienne, CubETH COM board flight model design and test
  • Fall 2014, Beat Geissmann, Testing and validation of attitude determination control subsystem for pico-satellites
  • Fall 2014, Raphael Zufferey, Digital sun sensors integration and characterization for pico-satellites
  • Fall 2014, Alessandro Fichera, CubETH – Antennas
  • Fall 2014, Rémi Laure, Sat I2C Bus communication protocol design
  • Fall 2014, Dimitri Mazourenko, Model-Based design of nanosatellite flight software
  • Fall 2014, Pasquale Longobardi, CubETH EPS software