...
...
...
...
...
...
...
...
...
...
Table of Contents
| Table of Contents | ||
|---|---|---|
|
All Requirements
2024 Regs (need to comply with 2026, which are not released) https://www.americansolarchallenge.org/ASC/wp-content/uploads/2023/11/ASC2024-Regs-EXTERNAL-RELEASE-C.pdf
Leader Board
MCU
2x CAN chips and in/out connector pairs
Controls CAN
Car CAN
Receive main power/ground
Receive isolated power/ground
Supply 1x power/ground for peripheral SOM
Peripheral Board - Pedals
1x: Front-ish middle
Step down & supply power to (3.3V?)
Accelerator pedal
Brake buttonpedal
Read position of accelerator pedal (potentiometer)
Read if brake pedal is pressed (buttonpotentiometer/brake line)
Sense if pedals are disconnected
Peripheral Board - Lights
5x: Front left, Front right, Side left, Side right, Back left, Back right, Canopy
Supply power to 2x 4x lights
Interface with 1x blindspot camera
Send camera output to display [board] (alternative: direct routing from camera to display)
[Backup GPIO for 2x lights?]
MOSFETs
Canopy psom
Current design:
Design Option—cameras
Powering the cameras using a peripheral board vs pi ethernet
Using Power Over Ethernet (POE)
if we use an ethernet connection, we wouldn’t need to connect the cameras to peripheral board at all—would be directly connected to the dashboard (or display?) ethernet cable (pi is connected to wherever the ethernet cable is connected to)
would only need the psom to power central brakelight
Using peripheral board
L4 chip (on peripheral board) does not have ethernet
if we connect the cameras to the pi, this is not a problem
ethernet kinda may not be super stable
just need to add power breakouts to lights board
Questions to answer:
can our psom power the cameras?
does the raspberry pi 0 connect to ethernet?
can attach a HAT to the pi or create an adapter
display will need either ethernet connection or some other protocol in order to display cam data
If we use POE, would we need two lines between each camera and the pi to power the cameras and also send data to the pi the to the display?
flow of data: camera sensors → pi 0 → display
Consider that we need a board for blindspot cameras
Convert ethernet → pi and from pi → HDMI for display
Peripheral Board - Contactor Board
does array need precharge - yes, but not our domain
Need to send ignition message to BPS - software
Design Decisions
Combining Left/Right Lighting boards for the front and back lights
Separate:
4 wires between left and right psoms
CAN H/L
Power/ground
Combined:
4 wires going left/right from board
Turn signal
Head/tail lights
Pros to combined:
One/two less boards
Less soldering
Less wiring: Eliminates CAN and power wiring between boards
Less boards to order and test
Cons to combined:
Longer power wires
More complex board
Supply both sides
Logic to toggle left or right (maybe not that difficult)
Justification
Overall wire length is the similar (Four wires- only difference is CAN vs GPIO)
GPIO would likely by 12V and therefore will not suffer a large voltage drop while crossing the width of the car
Added capabilities aren’t complex
More GPIO,
Powering cameras
Current decision: leaning towards using ethernet to power cameras
Pros to ethernet:
if we use an ethernet connection, we wouldn’t need to connect the cameras to peripheral board at all—would be directly connected to the dashboard (or display?) ethernet cable (pi is connected to wherever the ethernet cable is connected to)
would only need the psom to power central brakelight
can attach a HAT to the pi 0 or use usb to ethernet an adapter
cable can both power camera and send data ( ? )
Cons to ethernet:
More work to figure out how to do that (maybe not that hard? idk)
ethernet stability concerns?
new wiring requirements
will need a network switch (can buy or make ourselves)
Relevant Regulations (FSGP/ASC 2024)
...