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• Meeting Minuteses

• Version 2

Decisions since Schematic Review

• Replace LSM6DSL+ADXL375 with LSM6DSO32

• uhh Jlelyebans in the circuits? nat help

Schematic Review 1 Updates

• ADXL375 runs at Bus speeds. Higher bus speed → higher data rate

• Maybe getting jimfluenced into using a +/- 32 g accelerometer so we have the same high g low g acc. After boost happens, drop range to +/- 4g for higher precision https://www.st.com/en/mems-and-sensors/lsm6dso32.html

• Need bisexual ESD protection - was screwing with rs485 + ethernet

• Update buzzer schematic. (Choose a passive buzzer, P chanel switching or charge pump with n channel to make sure it actually switches)

• Grim pins float on flashing/bootup? might explode the rocket

  • and gate with delayed power? i think thats what jim said

  • check for FUSA AEQ rating for functional safety: pins dont go high until you tell them

• Bens Deployment schematic works but we got lost in the sauce and lost it in altium

Updates since presentation

• Using stm32f7 - easier to integrate + still has all the features we need

• QSPI flash to mitigate data storage rate worries from grim

• STLink MINIE instead of STLink MODS. Less space taken up on board technically less features but covers the features we were planning to use on mods. Maintains compatibility with j-links as theres stdc14 to jtag connectors.

• Selected LAN8742A for PHY transceiver. Used on the nucleo for the f7 and we’re going to steal their circuit1

• Move BME280, LSM6DSL, ADXL375 to SPI (they all have zephyr drivers and have proven to lock up our i2c bus). MS5611 and INA260 stay on i2c bc we either sample them very slowly or don’t wanna write a SPI driver for MS5611.

Presentation Notes

• Do we want to make the 2 P-IO pins on i2c pins or PWM pins (routing)

• Old temperature Requirements (10F-110F) were silly

  • 0C-50C is prolly good

• Pick requirements for sensors more betterly

  • Gyro: Small angular random walk

• How would it work if we lost power? -dean

  • Altimeter boost detect would probably still work

  • IMU boost detect wouldnt

  • Just dont loose power lol

• Configurability in field

  • really vague requirement (telling aaron to reflash them is configurabililty in field)

  • has a console to reconfigure - better way to say that

• Don’t need arming switch

• Make boost detect requirement verify by test

• Conops was not a conops

  • wiring was a little nasty

• DE9 Pin shenanigans

  • 2x ematch
    2x rs48
    2x PIO
    5v
    GND
    ematch bypass

  • breaking out kinda sketchy

    • but we need to break it out anyways so

• BMP388 vs 390. which one is available

• board space might be tight

• make a harness diagram for a de9

• Little plane whats the deal with that

  • Image Added

  • sketchy header thingy to power mod would work

• stlink cut first

  • takes up a lot of space

  • dont have compatibility with jlink

  • is convenient tho

• Leds should run at 3.3V

• Double check buzzer stuff

  • can it actually make music

History

The first era. Deployment Mod

Originally, we were under the impression that Brain Board was non functional. We know now that it was untested.

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TLDR; a more flexible RRC3 that could also act as a backplane module.

The second era. Brainsor Mod

At the beginning of the 2024-2025 school year, the project was brought up to the powers that be.

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• Use tested sensors - As of Irec 2024, all of sensor mod sensors were working from Aarons assesment and theres a good overlap there with grim sensors we were already planning on using

• use an stm32h series chip. Allows us to use new launch libraries w/ zephyr but with greater power and dual cores.

• Keep the ability to deploy charges

• Drop the dual power sources from the board itself. They provided a lot of complication and with more sensors (sensor mod has more than grim) and the components for deployment, space was at a premium on the board.

  1. In order to still have the ability to do test flights in L1s and L2s, "little plane" was to be developed. It has not yet been decided what form that would take

  2. Biplane: Aaron brought this up as something he'd been working on but it was not discussed much. I don't know what form this takes

  3. Payplane. Still a thought experiment at this point but it also has the ability to fit into a smaller rocket as it will have to fit into a payload

  4. Power Module Passthrough: A double sided board that has brainsor mod on one side and power mod on the other. W/ or w/out a switch. We know powermod works and if we don't require a switch (for a test flight of brainsor mod, we don't necessarily need to record power telemetry), could be incredibly simple - just headers and a little but of routing

  5. Powered Plane: Put electronics to supply the power required by the backplane standard onto the board onto which brainsor mod mounts. Would basically be what the original design of Deployment Mod but on two boards to simplify brainsor mod. Wouldn't need a switch since theres no one to talk to.

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