RPI Interface Rev B
- Daniel Puratich
- Ryan Scomazzon
- Mihir Gupta
Background
Changes discussed here 2024-06-25 Comp 2025 Architecture Sync - Meetings - WARG (atlassian.net)
Who
@Daniel Puratich architecture, ideas, schem, and layout
@Ryan Scomazzon helping with note taking during meetings
@Mihir Gupta & @Andrew Shum for testing the previous revision
@Meghan Dang for assembling the previous revision
Where
What
New Features
Add a power supply
Then the pi doesn't need an external power supply
Will use one I already designed
XT30 power input because we have board space!
Add a pilot controlled way to disable rpi commands
Someone should check if this is possible in software before we do this hassle.
fet to toggle communications (ps/rx/tx)
Motivation: Switch to manual control if we are doing something silly
Could use a GPIO that’s on the pixhawk header that pilot can toggle
Could use CTS and RTS pins to keep it on the same harness
confirm with firmware we can make this work in ardupilot configuration here
requires changing the code (not a simple param) but should be doable?
Will leave options to do both keeping in mind I have plenty of board space here.
Add an LED to blink if data is being sent over UART.
The FTDI cable we use has an LED that blinks when its connected and data is being sent over. It is very nice for debugging since we can see data is being sent. Would be sick to have something similar for this board ← request from @Mihir Gupta
Adding CAN circuit
Ardu supports mavlink over CAN so this would be doable with our common CAN circuit described in CAN Integration 2025 .
not sure if we wanna do this bc
it’s a large effort for firmware
lots of added cost and complexity
basically no benefit as we are highly likely to mount the Pixhawk in close proximity with the RPi
because we have plenty of board space i will do it and then we can leave it depopulated until a later date.
Fixes from mistakes on previous revision
Soldermask opening fixed on JST-GH conn
JST connector type
Will do JST do footprints for horizontal and vertical so we can choose which one we wanna use.
Holes slightly wider on Rpi conn
Not included features
Add 1:1 camera input header
For an analog camera that takes 5V
Just in case autonomy wants to use it. Unlikely but maybe …
This isn’t called for by Big Quad 2025 and is kind of just a guess based on Autonomy Compute Integration 2025 . Header can be DNPed if it’s not desired.
Design to match which also has a connector in .
This is not done because it’s on a different header than the normal 40pin one so not really worth it for a feature we don’t really need.
Notes
Market Research
https://www.rpanion.com/product/pi-connect-lite-v2/ very similar idea with just the power supply and pixhawk connector!