• Ready for review
  • Backplane

    Overview:

    Jus a big ole ethernet switch

    History

    Backplane:

    Rev 1.1.0→ RE @Billy S 22-23. Ethernet did not work because no magnetics. Rev 1.1.1 → @Ben Hyman 23-24. Before this revision we needed to determine if the ethernet issue was the lack of magnetics so with @James May we tested magnetics with Kludge, and it worked. Made rev 1.1.1 which added magnetics, USBc power, and new 30 pin keying. Note on USBc power; if another rev is needed implement a proper power mux current (1.1.1 is power after power mux, rationale was we are only going to use USBc power for testing). Main take away from this revission was look at reference schematics.

    Radio Module:

    Rev 1.1.0 → RE @Dante Sivo 22-23. Miraculously works. One module has a broken GPS

    Power Module:

    Rev 1.1.0 → RE @James May 22-23. Basically worked but had a slight volatge sag on the 3.3V rail. Rev 1.1.1 → RE @James May 23-24. Works really well.

    Autopilot Module:

    Rev 1.1.0 → RE @Ben Hyman 22-23. Mostly functional but there are a few issues. Buzzer not working (same as Grim Reefer need to swap out transistor). Ethernet works! Haven't fully tested to give good feedback 

    Sensor Module: 

    Rev 1.1.0 → RE @Mary Dertinger (RIT Student) @Louis Fleisher (RIT Student) and @Alex Moczarski (RIT Student) 22-23. Ethernet didn't work. MS5601/BMP address conflict. 2 layer..... caused some design decisions that could have been avoided. Bodged around Effuse wrong calcs for rising edge trigger  - voltage from power mod was 3.26 instead of 3.3.

    Rev 1.2.0 → RE @Mary Dertinger (RIT Student) @Louis Fleisher (RIT Student) and @Alex Moczarski (RIT Student) 23-24. Ethernet still doesn't work - we changed 30 pin to same but with shroud so part in Altium changed, footprint looked same but was different, so it was oriented incorrectly. MS5611 wired up wrong - connected main I2c clock to wrong pin was a copy paste error. Had DNP resistors but got populated (happened on 1.1.0 too) 3 bootstrapping for Wiznet and another for a sensor (R1). The issue was they were 0 ohm resistor so you had a short from power to gnd. No Effuse problems. I2c problems: too many transactions; bus will lock up. Same with 400 kHz will also lock up. thought it was because of LSM16

    Rev 1.2.1 → RE @Mary Dertinger (RIT Student) @Louis Fleisher (RIT Student) and @Alex Moczarski (RIT Student) 23-24 (Mostly @Louis Fleisher (RIT Student)). Ethernet works and overall functional but still testing.

     

    Requirements

    Requirement

    Rationale

    Satisfaction

    Requirement

    Rationale

    Satisfaction

    The backplane shall provide a method of communication between all modules

    Adding simple boards to the system should be relatively easy

    SwitchBlox Nano switch

    Each module shall be able to function independently to the best of its ability

    Allows computer to be in modular configurations depending on flight needs

    Sensor, Radio, Auto Pilot and Power - questionable because you need power mod

    The backplane shall route power to every board (from power mod)

    Boards need power

    Power mod but backplane routes rails to each module, 3.3V and 5V

    The backplane architecture shall define a standard width and height for each module

    Easier to mechanically integrate

    See backplane Standards

    The backplane shall survive launch operations

    A flight computer should be able to survive a flight

    Tested in 2 IREC flights

    Modules shall be individually mechanically accessible

    Speeds up prototyping/troubleshooting/repair

    NA

    The modules shall be drop-in interchangeable

    Speeds up prototyping/troubleshooting/repair

    See backplane Standards

    Each module should limit the amount of external I/O

    Prevents a rats nest in the avionics bay/payload

    See backplane Standards

    Flight History

    IREC 22-23 KONG → Flew with no power
    IREC 23-24 OMEN → Flew fully assembled but not fully functional, received one packet on from the pad but was useless because we plugged in wrong connector for radio.

     

    Highlights

    IREC 22-23 KONG podium session!! @Yevgeniy Gorbachev (RIT Student) presented → see attached presentation