2019-09-27 HW & FW Meeting

Owned by Arshan Khanifar
Last updated: Sept 30, 2019

Goal

  • To come up with firmware requirements for each board. 

All boards that need firmware: 

  • BMS Current Sense
  • BMS Carrier
  • Front Power Distribution
  • Rear Power Distribution
  • Precharge/Motor Controller Interface
  • GPS/Telemetry/Centre Display
  • Solar Sense
  • Pedal
  • Steering
  • Mech Sensor
  • Centre Console



BMS Current Sense

  • measures the current of a battery pack
  • iso-spi to bms carrier


BMS Carrier:

  • logs all 
    • voltage, 
    • temp, 
    • current info
    • relay states
  • used for state of the charge model: 
    • state of the charge status of battery how much eneergy
    • we need fast logging for a good soc model
  • controls the relay
  • if AFE undervoltage, we disconnect the entire relay
  • you can also disconnect from car power button so that comes from can
  • other conditions: 
    • overcharge
    • over temperature
    • over current
    • undercharge
    • power distribution tells u something’s wrong
      • dc dc failed
    • precharge board: 
      • precharge failed 
  • controls fans based on the temp
  • car turn on: checks battery pack status, then connects relays
  • turns on the current sense board: firmware doesn't need to care 
  • PI will be SOC algorithm
    • connetion between pi's havne't made decision

How it works: 

  • three AFE's 
  • gpio's control the mux
  • adc: for reading measurements
  • we talk to this bish using iso-spi
  • LTC6811 is the chiB

Front Power Distribution

Things that it powers:

  • driver display
  • driver control: steering, centre, pedal
  • front lights
  • dashboard indicator
  • horn
  • driver fans 

When we're powering off of aux:

  • the only thing we're driver display and driver controls: pedal, steering

Rear Power Distribution

Things that it powers:

  • BMS
  • rear lights
  • strobe light
  • motor controller interface
  • solar sense

When on aux:

  • BMS
  • Rear lights

How it works:

  • GPIO
  • I2C

Motor Controller Interface/Precharge:

  • separate can network to tell motor controllers to drive
  • Precharge completed happens through hardware, we need to know that only from CAN 
  • when capacitors are charged, it’ll send “precharge completed” message 
  • motor controller status logging
  • nice: motor controller restarting in firmware 
  • nice: limiting motor controller’s current sink by controlling it via firmware
  • nice: log motor stuff: all errors, and temperature over can 
  • nice: motor current access. 

Pedal & Steering:

  • whole lotta ADCs

Centre Console:

  • gpio