EVC Autonomous - Electrical

Autonomous Project electrical stack code

Autonomous Control/Distro Board

CAN messages

• ID = 0x100 - Control commands (RX)
  • Byte 0-1: throttle (uint16_t, little endian), 0-1000, where 1000 = full throttle
  • Byte 2-3: steering (uint16_t, little endian), 0-1000, where 500 = straight, 0 = full left, 1000 = full right
  • Byte 4-7: reserved / future use
• ID = 0x101 - Status update (TX)
  • Byte 0: state machine mode + rc mode
    • Bits0-3 = state machine mode (see logic.h::logic_mode_t)
    • Bit4 = RC mode (0 = rc mode, 1 = autonomous mode)
    • Bits5-7 = reserved
  • Byte 1-2: throttle PWM (uint16_t, little endian), the actual PWM value being sent to the ESC for throttle (1000-2000)
  • Byte 3-4: steering PWM (uint16_t, little endian), the actual PWM value being sent to the servo for steering (1000-2000)
  • Byte 5-7: reserved / future use

RC configuration

• Throttle
  • Channel: 2 (index 1)
  • At idle (center position): 1500 microseconds pulse width
  • At full throttle forward: 2000 microseconds pulse width
  • Pushing the throttle stick back still sends 1500
• Steering
  • Channel: 4 (index 3)
  • At center position: 1500 microseconds pulse width
  • At full right: 2000 microseconds pulse width
  • At full left: 1000 microseconds pulse width
• Mode switch
  • Channel: 5 (index 4)
  • In RC mode: 1000 microseconds pulse width (not activated posistion)
  • In autonomous mode: 2000 microseconds pulse width (activated position)
• E-Stop switch
  • Channel: 6 (index 5)
  • Not pressed: 1000 microseconds pulse width (not activated position)
  • Pressed: 2000 microseconds pulse width (activated position)

Pin Definitions

• CAN Bus (CAN2):

  • RX: PB5
  • TX: PB6
  • CAN_S (Silent): PB7
    • LOW to enable transmitter
    • HIGH to disable transmitter

• VESC COMMS (UART5):

  • RX: PD2
  • TX: PC12

• RC Reciever (USART3)

  • RX: PB11
  • TX: PB10

• USB (Bootloader):

  • DM: PA11
  • DP: PA12

• STEERING OUT (PWM):

  • TIM1 (CH1/CH1N): PE9

• THROTTLE OUT (PWM):

  • TIM11 (CH1): PB9

• GPIOs:

  • CAN_S: PB7
  • Main Coil EN: PE5
  • Precharge EN: PE6
  • LED OUT: PE8

• System / Debug:

  • SWDIO: PA13
  • SWCLK: PA14
  • OSC_IN/OUT: PH0 / PH1 (8MHz HSE)

State Machine

Autonomous Nucleo

Pin Definitions

• Rubik Pi 3 <-> nucleo-f446re: SPI2
  • SCK: PB10
  • NSS: PB12
  • MOSI: PC1
  • MISO: PC2
• Motor controller control: TIM2
  • Output: PA15
  • 1000-2000 microseconds pulse width (stop - full forward)
• Steering servo control: TIM3
  • Output: PA6
  • 1000-2000 microseconds pulse width (left - right)
• RC contactor/e-stop PWM input: TIM5
  • Input: PA0
  • >=1800 microseconds pulse width to close contactor
• GPIOs:
  • LD2: PA5
    • Output
    • On nucleo green LED
  • B1: PC13
    • Input: external interrupt mode on falling edge
    • On nucleuo button
  • CONTACTOR: PB8
    • Output: pull down
    • Set high to close contactor