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Goals / Background / Strategic Fit / Requirements

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• Kill Switch flipped (?)
• AFE Under/Over volt
  • Disconnect relay

Block Diagram 

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Revised Block Diagram

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Design Notes

• Main initializes killswitch, current_sense, battery_heartbeat, cell_sense, and fan_control. 
• Killswitch, current_sense, and cell_sense need direct access to battery_heartbeat in order to quickly raise or clear faults.

Detailed Design / Modules

Main

• Initializes other modules, initializes CAN and other modules
• Stores most updated measurements
• Current
• Cell voltages
• Cell temps
• Relay state
• Fan speed
• 
  Killswitch

• Initializes a debounced GPIO pin to handle killswitch presses
• Exposes init

• Battery_heartbeat

• Periodically transmits battery status and receives acks
• Exposes ability to raise and clear faults based on a bitset, and init
• Opens relays in case of fault and updates relay state

• Relay_control

• Statically sets relay state, updates stored state, and returns whether the relay state set was successful.
• Exposes set_relay_state

• Current_sense

• Registers an interrupt to update the stored current value based on ADC reading
• If the updated current value is above a threshold, raise overcurrent fault
• If the overcurrent fault bit is set and the updated current value is below the threshold, drop the fault bit
• Exposes init

• Ads_1259

• Driver for the ADS1259 24 bit ADC
• Exposes ltc_adc_register_callback

• Cell_sense

• To be ported from MSXII firmware.
• Raises / lowers faults similar to current_sense, including overcharge, over temperature, over current, under charge

• Fan_control

• Periodically updates the fan speed based on the temperature
• Uses an offset linear fan control curve based on the desired operating temperature of the battery (refer to datasheet)
• Exposes init

Meeting Notes

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

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LTC6811 (Battery Monitor) Datasheet - https://www.analog.com/media/en/technical-documentation/data-sheets/68111fb.pdf

Car's Power States

Old Block Diagram 

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This block diagram is highly inspired by MSXII's Plutus. Some minor adjustments were made to make it slightly more easy to understand.

Reasons to revise:

• Relay_control doesn’t need to be under fault_handler since it’ll also receive messages from center console
• Event driven architecture
• System_init is not necessary since startup logic is handled by center console
• Fault handling is also moved to center console