SPARCCS Spring 2016: Critical Design Review (CDR) Debrief

Posted by Mikhael Semaan (Project Manager).

Original notes taken by Eric Hanna (Design and Manufacturing).

Table of Contents

These are our notes from meeting with Mr. Hill, the instructor of EE 400D, following our CDR Presentation [1].

General Notes

  • Overall, the presentation was very polished.
  • Need to completely black out the camera to detect single-event upsets (SEUs).
  • Taking off the lens is an idea, but not realistic within the time-frame (something for next semester, perhaps?).
  • At this point we need it to work, so we can cover with electrical tape.
  • Show basic functionality.
  • Future semesters need to do further testing, especially on radiation detection and SEU/camera stuff.
  • We’re not detecting a flipped bit, we’re detecting a filled potential well (with the camera).
  • Nailed the Executive Summary.
  • Need a little more detail in System Design for the final blog post.
  • No UART or COMM on PC/104. Put this in “lessons learned” for future groups.
  • DB9 still a good idea, because it allows us not to “use up” the lifetime of the PC/104 connector with too much connecting and reconnecting. Pigtail connector in the future?

Lessons Learned

Experimental Results

  • There were lots of trade-off studies,
  • not so much “experiments.”
  • Requirements must link to higher-level requirements for trade-offs and experiments.

Interface Definition

  • Didn’t show cable routing.
    • Even though we don’t have any cables to route, we should have acknowledged that explicitly.

Fritzing / PCB

  • Fritzing diagram could have been nicer (i.e. curved wires).
  • Mention that the PC/104 bus is standardized and is a standard often used in CubeSats.

Hardware Design

  • Explain how it’ll mount in the chassis better.

Software Design

  • Nice, but could’ve seen more code.
  • Curious about different materials to block camera.
  • What constitutes an SEU?
  • Light leakage from lens? (cover with tape?)

Verification and Validation Test Plan

  • Could’ve seen distinction between “verified” versus “validated.”
  • We treated the DC-HVDC converter as an IC, but it’s not. It’s a module, and we don’t technically know what’s in the module. Lesson learned: in the future, stay away from modules unless we know what’s inside.

Project Update

  • Realistic Burn-Down on how behind we are.
  • Need to update Resource Reports to reflect the final Bill of Materials.

Demonstration

  • Paul sent an article on hot-pixel detection. Look at it [2].
  • Camera covering (this will change).

References

  1. Semaan, M., E. Hanna, C. Mediavilla, and J. Seiden (2016). “Critical Design Review.” EE 400D Spring 2016, California State University, Long Beach.
  2. Chapman, G. H., R. Thomas, R. Thomas, K. J. Coelho Silva Meneses, T. Q. Yang, I. Koren, Z. Koren (2015). “Single Event Upsets and Hot Pixels in digital imagers.” 2015 IEEE International Symposium on Defect and Fault Tolerance in VLSI and Nanotechnology Systems.