Critique my design: CubeSat reaction wheel demo

[Cormac_McCarthy]

Hello all,

I am new here, is this still an active community? I wanted to use parts listed on this site for my project but many of them are no longer sold.

Anyway, I would like to share what I am doing and get some critiques because I honestly have no idea what I am doing.

So here’s the project:

I am designing a demo of 3-axis satellite pointing using reaction wheels.

Parts list:

MC: Adafruit MetroM4 Airlift Lite
IMU: Adafruit BNO055
Motors: 3x RCTimer 90KV Gimbal Motors
Motor Drivers: 3x SimpleFOC Minis
Encoders: AS5048A Magnetic Encoders
Power: 3S LiPo Battery, 5V step-down regulator (for MC power)
Various 3D printed components

The attached schematic is mostly to help me visualize and I’m certain I violated a thousand conventions in it but if you can look past that I would appreciate critique if you see any glaring issues with the setup. Also if you think there will be any compatibility issues with the components I am using; most of them have not arrived yet.

Thanks for reading!

[iso14000]

in green => ambiguity

in red => errors

no decoupling/reservoir cap, floating pins, floating gnd, lack pull up on I²C lines etcetc….

best regards

[Cormac_McCarthy]

Thanks for taking the time to respond. I have 1 decoupling cap in there but are you saying I should have one for each motor? Also the BNO055 is on the adafruit breakout board so no external pullup resistors are required.

[iso14000]

usually when a review is scheduled, it is necessary to give, at least , all datasheet (or links to)

please redraw your design, remove power lines from bus, gnd shoud be … bottow oriented and not hanging like a bat . Enable lines for drivers should be pull downed by resistance to gnd.

there is definitly lack of decoupling caps , and reservoir caps..

don’t know what is your regulator,

you should segregate the power for BLDC and power for digital ,

[Valentine]

@Cormac_McCarthy

is this still an active community

Yes.

Cheers,

Valentine