Controls Lighting Board Requirements (●ˇ∀ˇ●)

Owner	Lucy Xie
Status	IN PROGRESS
Contributors	Madeleine Lee Zoe Gonzalez Diya Rajon
Approver	Diya Rajon
On this page	Lights Overview Camera Wiring Decision Combining Left/Right Lighting Boards Decision

Lights

We will have five peripheral boards for lights in total.

Location:

Front (headlights and turn signals)
Side left (exterior turn signals? *ask why the arrow is going into the peripheral SOM and how its different from front SOM)
Side right (exterior turn signals?)
Back (exterior brakelight?)
Canopy (brakelight?)

There will be 6 GPIO connectors on the board (4 needed, 2 for backup)

Camera Wiring Design Options (Canopy)

Controls must decide how we want to power the backup camera and 2 blind spot cameras, as well as how to send camera information to show on the display.

Goal is to stream video 20-20 fps

Three options:

Power through ethernet
Power through USB
~~Power through peripheral board~~ very unlikely option

Power through ethernet

Power through USB

(Akshay Gaitonde currently researching)

Power through peripheral SOM

How it works

Ethernet will allow us to send data and power the cameras at the same time
Information travels from camera(s) to a network switch, which connects to raspberry pi, which connects to display
Network switch is essentially a mux that can choose which camera’s stream information to send

Add power breakouts to peripheral board to supply power to cameras
Send information through CAN?

(scuffed) general diagram

Pros and cons

Simplicity

Keeps peripheral SOM simple

Possibly easier for wire harnessing

Long ethernet wires

New wiring requirements needed

Need to purchase/make(?) network switch

Possibly not that much more to be added to peripheral SOM

Running video information over CAN is probably a bad idea

Board may not be able to supply enough power

🤯Decision

No final decision yet.

Combining Left/Right Lighting boards

There are lights (internal and external) on the left and right side of the car, in both the front and the back. Controls must decide if we should have four boards for front left, front right, back left, and back right, or just two for front left/right and back left/right

	Four boards	Two boards
Overview	4 wires between left and right psoms CAN H/L Power/ground	4 wires going left/right from board Turn signal Head/tail lights
(scuffed) general diagram
Pros and cons	Not that much different power-wise (i think?) More boards = more expensive More difficult for wire harnessing	Less soldering Less wiring: Eliminates CAN and power wiring between boards Less boards to order and test Longer power wires More complex board: must supply power to both sides + logic to toggle left or right side

🤯Decision

Yes, we will combine them.

Justification:

Overall wire length is 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