BMS Carrier Firmware

Goals

Detail the behaviour of the BMS carrier board and how firmware should enable/control it

Background and strategic fit

Overview of Board Behaviour (Firmware)

Inputs 

Outputs 

Possible Events (Internal / Synchronous) 

Possible Events (External / Out of our control / Asynchronous)  

Requirements

Meeting Notes

• logs all 
  • Voltage, 
  • Temp, 
  • Current
  • Relay States
• Controls
  • Relays

• 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
  • overcharge
  • over temperature
  • over current
  • undercharge
  • power distribution tells u something’s wrong
    
    • dc dc failed
  • precharge board: 
    • precharge failed 
• controls the relays
• if AFE undervoltage, we disconnect the relays
• you can also disconnect from car power button so that comes from can
• other conditions: 
• 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 it's literally a line that goes to it.
• PI will be SOC algorithm
  
  • connetion between pi's havne't made decision

How it works: 

• Three AFEs 
• Temperatures measured via thermistors (AFEs)
• gpio's control the mux (for AFE)
• adc: for reading measurements
• we talk to this bish using iso-spi
• LTC6811 is the chiB
  • https://www.analog.com/media/en/technical-documentation/data-sheets/68111fb.pdf

Questions