Bigtreetech Octopus

Wiring for the Octopus boards is very straight forward with all pins directly available on the EXP2 header.

../../_images/OCTOPUS-pro-pin.png

OCTOPUS PRO

../../_images/OCTOPUS-v1-pin.png

OCTOPUS v1.1

Firmware and Config

The Octopus has several different versions. Currently, the only supported versions are based on the STM32F446 and STM32F429 microcontrollers. Hardware wise they are mostly the same, but they require diferent firmware. Note which board version you have and choose the matching firmware.

  • Note : The MbedOS5 version of the 446 firmware overwrites the bootloader. A working version could not be realised at the time of writing, so firmware updates afterwards need to be done with STLINK or the DFU boot via USB-c. The original bootloader is avaiable on the BTT github page.

  • Note : The MbedOS6 version of the 446 firmware has bootloader support.

  • Firmware for the STM32F429 version is STM32F429/BTT_429

  • Firmware for the STM32F446 version is STM32F446/BTT_446

  • Firmware for other versions are unavailable or untested

In your .hal file, you will need to configure the Remora chip_type to “STM”

loadrt remora chip_type=STM

The config file for the Octopus will be the same for both versions.

Hardware Pins

Remora firmware has some features available only on specific hardware pins. These pins can vary between STM32 boards.

Available PWM Hardware pins:

  • PA_1 PA_2 PA_3 PA_5 PA_6 PA_7 PA_8 PA_9 PA_10 PA_11 PA_15

  • PB_0 PB_1 PB_3 PB_4 PB_5 PB_6 PB_7 PB_8 PB_9 PB_10 PB_11 PB_13 PB_14 PB_15

  • PC_6 PC_7 PC_8 PC_9

  • PE_5 PE_6 PE_8 PE_9 PE_10 PE_11

Available QEI Encoder Hardware pins:

  • PE_9

  • PE_11

  • PE_13 is used as index

Wiring

The wiring for both versions are the same, except UART is in a different location. Wiring requires the following components:

  • 100mm Female-Female Dupont ribbon jumper

  • 10 way (2x5) Dupont connector

  • 8 way (2x4) Dupont connector

The pinout for the BTT Octopus is standard for both versions and keeps the footprint of the SKR v1.4 and SKR v2.

PIN

COLOR

FUNCTION

RPI PIN

PA_7

RED

SPI_MOSI

RPI_PIN_19

PA_6

ORANGE

SPI_MISO

RPI_PIN_21

PA_5

GREEN

SPI_SCK

RPI_PIN_23

PA_4

YELLOW

SPI_SSEL

RPI_PIN_24

PC_15

BROWN

PRU Reset

RPI_PIN_22

PA_9

PURPLE

MCU TX to RPI RXD

RPI_PIN_10

PA_10

GREY

MCU RX to RPI TXD

RPI_PIN_8
../../_images/Octopus-pro-wiring-diag1.png

OCTOPUS PRO

../../_images/Octopus-v1-wiring-diag1.png

OCTOPUS v1.1

To UART from the Raspberry Pi to the Octopus the follwoing components are requried:

  • 150mm or 200mm Female-Female Dupont ribbon jumper

  • 5 way (1x5) Dupont connector

  • 5 way (1x5) Dupont connector

../../_images/Octopus-pro-wiring-diag2.png

OCTOPUS PRO

../../_images/Octopus-v1-wiring-diag2.png

OCTOPUS v1.1

The diagram above includes the optional serial debug interface. Note that TX <-> RXD and RX <-> TXD.