1. The board size should comply with the PC/104 standard. There should be mounting holes at all 4 corners of the board.
   • PC/104 connectors are not needed for Rev #1
2. An operating temperature between -40°C and 85°C should be assumed and every component constituting the OBC should be able to operate within this range
3. An onboard temperature sensor must be available to keep track of temperature changes onboard the OBC
   • One main temperature sensor and one redundant sensor
     • A redundant sensor is not needed for Rev #1
4. An external memory/storage device should be made available in order to store code, housekeeping, and telemetry data before transmission to the ground station
   • https://www.digikey.ca/en/articles/the-fundamentals-of-embedded-memory
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5. Make the board easy-to-use for developers
   • Think about flashing the MCU, debugging code, and providing power.
   • Micro USB B (5V) to provide power to the board.
   • Status LEDs, buttons, JTAG header, and male headers for breadboarding.
   • Push buttons for power-on and resets.
6. A debug probe is needed for flashing the MCU
7. Regulated voltages of 3.3V and 1.2V should be available on the local power bus
   • This will be used for development purposes. EPS will provide the 3V3 rail for Rev #2.
   • 1.2V is used as the MCU supply voltage & 3.3V is needed for everything else
     • Produce these voltages with a dual buck converter on Rev #1 to convert the 5V USB input
8. Consider how the board will interact with other subsystems
   • If we decide to use the CAN protocol, we'll need a CAN transceiver
   • The flight board must have PC/104 connector(s). We won’t be using PC/104 for REV #1.
9. An over-voltage and current protection system should be implemented in order to trip the power and reset the OBC in case of a short circuit or instability in voltage levels. We should have latch-up protection (which involves the other stuff anyway) as well.
   • Overcurrent protection with a resettable fuse and current-sense amplifier
   • Voltage supervisory circuit
   • Latch-up protection
     • Latch-up protection is not needed for Rev #1
     • https://www.doeeet.com/content/eee-components/single-event-latchup-protection-circuits/
   • Overvoltage/Undervoltage/Reverse Polarity protection
10. Create a fault-tolerant system by practicing redundancy
    • We should have duplicates of important components (Temperature sensor, etc.)
    • Redundant components are not needed for Rev #1
11. If OTA software updates are to be done, external memory (MRAM/FRAM) is needed so we can store the original and new code images. Alternatively, we can dual-partition the main FRAM/MRAM
    • Check out section 6 of https://gitlab.com/acubesat/documentation/cdr-public/-/blob/master/DDJF/DDJF_OBSW.pdf
    • It’s been decided that we won’t be implementing OTA software updates for the time being.
12. A remove-before-flight (RBF) circuit is needed to ensure that the satellite starts operation only after ejection from the launch vehicle.
    • An RBF circuit is not needed for Rev #1. I believe another subteam should be handling this. Verify this.
13. An external watchdog is needed to monitor MCU programs to see if they work
    • An external watchdog is not needed for Rev #1
      • However, we may have other components that include an optional watchdog