Marling firmware using an Anycubic Chiron upgraded with an SKR 2 motherboard

HUGE THANKS TO EvilGremlin WHICH DID MOST OF THE WORK 💖

SRK MCU

This firmware build is for the newer SKR 2.0 board, they mount the STM32F429 MCU, if you use the STM32F407 you will have to edit the line in platformio.ini (you will have to check to right code to use):

default_envs = BIGTREE_SKR_2_F429 

FIRMWARE

We are currently working on the bugfix Marlin version since in the latest release the STM32F407 MCU has not been implemented yet.

SENSORLESS HOMING

You will need the TMC2209 stepper drivers, and a BLTOUCH, you will need to make additional changes in case if:

• You have a different hotend mount (you will need to change the probe offset)
• You don't have the TMC2209, you will have to turn off the sensorless homing feature
• You don't have a BLTOUCH, you might still be able to use sensorless homing for the Y and X axis, but you will need to leave the stock z axis end stops.

Z DOUBLE STEPPER MOTORS

The chiron has 2 Z motors, to move each motor indipendently it's important to use the E1 slot in the motherboard to connect one of the Z stepper motor. If you use the Z1 slot you will have both motors moving not indipendently.

TFT

The stock LCD was giving too much problems, the SKR 2.0 doesn't have a beeper pin in the TFT slot meaning the LCD would need a review and additional work which is not worth.
This firmware version works with a BTT TFT35 E3 V3.0 LCD.

HOTEND/EXTRUDER

This firmware is tuned to work with an Hemera.
Here's the thingiverse mount file:
Thingiverse file
BLTcouch offset with this mount:

#define NOZZLE_TO_PROBE_OFFSET { -38, 3, -2.66 }

FANS

The SKR 2 has 3 fans slots, I use the:
FAN 2 to cool down the TMC2209 *
FAN 1 is used to cool the hotend
FAN 0 is used for part cooling

In case you want to edit the pins:

#define CONTROLLER_FAN_PIN FAN2_PIN //FAN2_PIN is FAN 2 which I use for the TMC and MCU cooling

#define E0_AUTO_FAN_PIN FAN1_PIN //FAN1_PIN is FAN 1 which I use for the hotend

//FAN_PIN is by default the cooling part fan

Pins are declered in pins_BTT_SKR_V2_0_common.h file

• I used a conversion part to replace the Trigorilla to a SRK 2. Thingiverse file
  

IMPORTANT:
Currently the PWM fans don't work!
We need to wait for marlin to work on the SKR 2 and fix this issue.
You can just plug the the TMC2209/MCU cooling and the hotend fun to the 24V sockets.
FAN 0 can still be used for cooling part (it works).
FAN 3 & FAN 4 are the one you need to use for the TMC2209/MCU cooling and for the hotend cooling.

BLTouch

I'm currently having problems to understand what's wrong, so work in progress here as well.

PINS TUNING

In case you have problems with this firmware version make sure that you are using the right pins: PINS MAP

Work in progess, wait for a stable version.