This page documents all of car's power states.

Power States

On: Car is on and main battery's driving the power.
Off: Car is turned off, only parts of the car are on to facilitate the startup. It's powered off of Aux battery.
AUX: Car is turned on without holding the brakes, this will put the car in a mode where some parts: driver display, centre console, etc. are powered.
Emergency: Car was previously on, but some fault happened and therefore parts are disconnected.

Power On (Aux):

Description

User presses the power button and the car goes on the Aux power state.

Note: won't need to check DC-DC here.
Todo: do the sequencing here too...

Possible Outcomes

Condition	Outcome
Aux BMS indicates a fault.	Car won't turn on, all of the boards other than AUX BMS will be off.

Power On (Main):

Happy Path:

Requirements:

AUX Batteries are powering the boards AND have enough charge to close the relays.

User presses the power button while holding the brakes and the car will eventually need to get in the state where the main batteries are connected, and all the boards are being powered from the main battery. Steps are as follows:

User holds the brakes down.
Pedal Board sends a message to the Centre Console.
Centre Console receives the message and now knows that brakes are pressed.
User presses the power button.
Centre Console receives power button press, and will begin the power-up process.
Centre Console sends a message to Front Power Distribution to turn on Driver Display.
Centre Console sends a message to Aux BMS/Power Distribution to ensure we have enough voltage to close the relays.
Aux BMS/Power Distribution says that there IS ENOUGH CHARGE.
Centre Console sends a message to Rear Power Distribution to turn on BMS Carrier
Rear Power Distribution turns ON BMS Carrier, checks if there's no faults.
BMS Carrier tells Centre Console that it's UP.
Centre Console asks BMS Carrier for the state of the batteries and relays.
BMS Carrier checks the state of main battery (includes making sure battery relays are open), state is OK.
BMS Carrier responds to Centre Console.
Centre Console sends a message to Rear Power Distribution to turn on Motor Controller Interface/Pre-Charge.
Rear Power Distribution turns ON Motor Controller Interface/Pre-Charge, checks if there's no faults.
Motor Controller Interface/Pre-Charge tells Centre Console that it's UP.
Centre Console tells Motor Controller Interface/Pre-Charge to check the status of cable connections.
Motor Controller Interface/Pre-Charge tells Centre Console that cable connections are okay.
Centre Console asks Motor Controller Interface/Pre-Charge for the state of the motor relays.
Motor Controller Interface/Pre-Charge responds to Centre Console, state is OK.
Centre Console sends a message to BMS Carrier to close the battery relays.
Centre Console asks BMS Carrier if the battery relays got closed.
Centre Console sends a message to Motor Controller Interface/Pre-Charge to start the pre-charge process.
Motor Controller Interface/Pre-Charge WILL KNOW that pre-charge is done, will let Centre Console know that pre-charge is done.
Centre Console asks Rear Power Distribution if DC-DC has connected, therefore it's getting its power from Main Battery. (Note: other boards are not powered yet!)
Centre Console should ask both Rear Power Distribution and Front Power Distribution to close all of their switches.
Both Rear Power Distribution and Front Power Distribution check if there's no fault at the switches, and lets Centre Console know that we're good.
Centre Console sends a message to Motor Controller Interface/Pre-Charge to close its relays.
Motor Controller Interface/Pre-Charge lets Centre Console know that relays are closed FOR REALZ.
Driver Display will ask Centre Console for status: all the status are fine, and will indicate that WE CAN DRIVE!

Concerns:

Question	Answer
What happens if the user releases the pedal, but the CAN message gets dropped, therefore centre console won't know if the pedal was released.
By default, Centre Console, Front Power Distribution, Pedal Board, will be on. Will this require too much power? Can we save by putting boards into sleep mode? How long until this drains the Aux Battery to a state where it cannot power the boards?
Heartbeat from BMS Carrier? Who needs to hear this heartbeat? What to do if it's missed?
CAN's not isolated, what happens if one of CAN lines acts as the ground? need to make sure that doesn't happen!!!!	Look at the data-sheet for the CAN transceiver. That may have info.
LET'S PUT A SELF-TEST!!! WHOOHOOO	meetup coming soon...

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