Firmware Specifications

Board Requirements

• Distribute power to the ODRIVE’s, 5V system and Nvidia Jetson (17V)

• Monitor the loads going to these devices

• Shutdown the outputs of the loads become dangerously high

• Monitor the voltage rails for any anomalies

• Indicate board level/PDB status through onboard RGB LED

• Drive the LED matrix via PWM signals

• Listen for and send data to the Jetson

Basic Operating Principle

• Faults will be handled by the STM on the PDB

• Fault conditions should be cleared by the Jeston or power cycle

• Jetson determines the PWM outputs

• PDB sends state information to the Jetson

• The Jetson just clears faults and updates the PWM levels

Flow Chart

Comments:

• Things to consider

  • CAN TX + RX(ISR) SET 1 & 2 [PA11&12 CAN A] [PB12&13 CAN B]

    • To-do: define interface between jetson and PDB

    • Setup ISR for handling CAN message

  • Monitoring:

    • 48v rail:

      • 48v VBAT IN monitoring:

        • voltage divide 50/16 =3.125

        • determine what will the threshold voltage be

        • PC4 (VBAT ADC Input)

      • 2 48v to odrive, 2.5A each

        • read MPQ8112GJ-AEC1-Z datasheet

        • measure current on PC0 (Odrive 1); PC2 (Odrive 2)

        • Update enable state variable for input on PC1(Odrive1 EN); PC3 (Odrive 2 EN)

    • 24v rail:

      • 48v → 24v buck, 15A each

        • read MPQ8112GJ-AEC1-Z datasheet

        • measure current on PA7 (Vbat Buck Current); PA5 (Odrive3)

        • Update enable state variable for input on PC5(Vbat Buck EN); PA6 (Odrive 3 EN)

reference:
OUT = 50(RG1 - RG2)
OUT: (0-3V)
CURRENT: (0-30A)
RSENSE = 0.002Ohm

OUT MAX = (0.002ohm)(30A)(50) = 3V
MAX_POWER = (0.002ohm)(30A)^2 = 1.8W

TO-DO: Still need spec for 17v and 5v and other important setup for PDB Mock up testing

need to setup a testing procedure document for testing the mock up system