droxeybot

@droxey's customized Ender 3 build featuring SKR Mini E3 V2.0 / Hemera / Filament Detection / BLTouch / UPS / Power Relay.

Component	Part	Repo
Motherboard	BTT SKR MINI E3 V2.0	BIGTREETECH-SKR-mini-E3
Extruder	Hemera Direct Drive	-
Power Supply	MeanWell LRS-350-24U	-
Filament Sensor	BTT Smart Filament Detection	smart-filament-detection-module
Relay	BTT Relay v1.2	BIGTREETECH-Relay-V1.2
UPS	BTT UPS 24V V1.0	BIGTREETECH-MINI-UPS-V2.0
Leveling / Z Endstop	BLTouch v3.1	-
Dual Z Axis	ExoSlide XZ Kit	-
Upgraded Y Axis	ExoSlide Y Bed Kit	-

Table of Contents

• Configure Firmware
• Connect Hardware & Add Features
  • Step Daemon
  • Jumpers
  • BLTouch
  • UPS
  • Relay
  • Smart Filament Detection Module
• Resources & Credits

Configure Firmware

$ git clone git@github.com:MarlinFirmware/Marlin.git
$ cd Marlin
$ git checkout bugfix-2.0.x
$ curl -o 1_UpdateFirmware.patch https://raw.githubusercontent.com/linsomniac/MarlinSKRMiniE3v2.0Files/master/essential_changes.patch
$ curl -o 2_BLTouch.patch https://raw.githubusercontent.com/linsomniac/MarlinSKRMiniE3v2.0Files/master/bltouch.patch
$ patch -p1 <1_UpdateFirmware.patch
$ patch -p1 <2_BLTouch.patch

Connect Hardware & Add Features

Step Daemon

Step Daemon (stepd) is an external planner for 3d printers that utilizes Marlin compatible firmware to allow direct step processing by an external computer and enables the use of complex pre-processing.

Set it up on your Raspberry Pi by following the instructions in the project's README.

Jumpers

1. Remove the jumper from Z_DIA3 to use the BLTouch as the Z endstop.
2. Remove the jumper above Z_PROBE to enable the onboard 5v power supply.

BLTouch

Connect the BLTouch to Z_PROBE on the motherboard.

UPS

Connect the UPS module to the PWR_DE pin on the motherboard.

Open Configuration_adv.h and modify the following settings to match the following snippet:

 #define POWER_LOSS_RECOVERY
 #if ENABLED(POWER_LOSS_RECOVERY)
   #define PLR_ENABLED_DEFAULT   false // Power Loss Recovery enabled by default. (Set with 'M413 Sn' & M500)
   #define BACKUP_POWER_SUPPLY       // Backup power / UPS to move the steppers on power loss
   #define POWER_LOSS_ZRAISE       10 // (mm) Z axis raise on resume (on power loss with UPS)
   #define POWER_LOSS_PIN         PC12 // Pin to detect power loss. Set to -1 to disable default pin on boards without module.
   #define POWER_LOSS_STATE       HIGH // State of pin indicating power loss
   #define POWER_LOSS_PULL           // Set pullup / pulldown as appropriate
   #define POWER_LOSS_PURGE_LEN   20 // (mm) Length of filament to purge on resume
   #define POWER_LOSS_RETRACT_LEN 10 // (mm) Length of filament to retract on fail. Requires backup power.

   // Without a POWER_LOSS_PIN the following option helps reduce wear on the SD card,
   // especially with "vase mode" printing. Set too high and vases cannot be continued.
   #define POWER_LOSS_MIN_Z_CHANGE 0.05 // (mm) Minimum Z change before saving power-loss data
 #endif

Relay

Connect the relay to your power supply according to the diagram. Connect the relay to the PS_ON pin on your motherboard.

Open Configuration.h and make the following modifications to the firmware:

/**
 * Power Supply Control
 *
 * Enable and connect the power supply to the PS_ON_PIN.
 * Specify whether the power supply is active HIGH or active LOW.
 */
#define PSU_CONTROL
#define PSU_NAME "Power Supply"

#if ENABLED(PSU_CONTROL)
  #define PSU_ACTIVE_HIGH true     // Set 'false' for ATX, 'true' for X-Box

  //#define PSU_DEFAULT_OFF         // Keep power off until enabled directly with M80
  //#define PSU_POWERUP_DELAY 100   // (ms) Delay for the PSU to warm up to full power

  // #define AUTO_POWER_CONTROL      // Enable automatic control of the PS_ON pin
  #if ENABLED(AUTO_POWER_CONTROL)
    #define AUTO_POWER_FANS         // Turn on PSU if fans need power
    #define AUTO_POWER_E_FANS
    #define AUTO_POWER_CONTROLLERFAN
    #define AUTO_POWER_CHAMBER_FAN
    //#define AUTO_POWER_E_TEMP        50 // (°C) Turn on PSU over this temperature
    //#define AUTO_POWER_CHAMBER_TEMP  30 // (°C) Turn on PSU over this temperature
    #define POWER_TIMEOUT 30
  #endif
#endif

Finally, in your slicing software, add M81 to the bottom of your end script.

Smart Filament Detection Module

1. To configure the Smart Filament Runout Sensor, open Configuration.h and uncomment #define FILAMENT_RUNOUT_SENSOR. Then, ensure your settings match the following:

   /**
    * Filament Runout Sensors
    * Mechanical or opto endstops are used to check for the presence of filament.
    *
    * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
    * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
    * By default the firmware assumes HIGH=FILAMENT PRESENT.
    */
   #define FILAMENT_RUNOUT_SENSOR
   #define FIL_RUNOUT_PIN PC15 // Filament detection pin for BTT SKR Mini E3 v2.0
   #if ENABLED(FILAMENT_RUNOUT_SENSOR)
       #define NUM_RUNOUT_SENSORS 1 // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
       #if ENABLED(INVERT_FS_LOGIC)
           #define FIL_RUNOUT_INVERTING true // Trigger's alternative as soon as invert filamentsensor logic is activated
       #else
           #define FIL_RUNOUT_INVERTING false // Logic inverting is automatically taken care in section 13
       #endif
       // Set to true to invert the logic of the sensor.
       #if ENABLED(INVERTL_PINPULLUP_LOGIC)
           #define FIL_RUNOUT_PULLDOWN // Use internal pulldown for filament runout pins.
       #else
           #define FIL_RUNOUT_PULLUP // Use internal pullup for filament runout pins.
       #endif
   
       // Set one or more commands to execute on filament runout.
       // (After 'M412 H' Marlin will ask the host to handle the process.)
       #define FILAMENT_RUNOUT_SCRIPT "M600"
   
       // After a runout is detected, continue printing this length of filament
       // before executing the runout script. Useful for a sensor at the end of
       // a feed tube. Requires 4 bytes SRAM per sensor, plus 4 bytes overhead.
       #define FILAMENT_RUNOUT_DISTANCE_MM 7
   
       #ifdef FILAMENT_RUNOUT_DISTANCE_MM
       // Enable this option to use an encoder disc that toggles the runout pin
       // as the filament moves. (Be sure to set FILAMENT_RUNOUT_DISTANCE_MM
       // large enough to avoid false positives.)
           #define FILAMENT_MOTION_SENSOR
       #endif
   #endif

2. In Configuration_adv.h, make the following changes:

   1. To enable runout detection on serial LCDs, uncomment #define M114_DETAIL. This allows runout detection to function in Marlin Mode.
   2. To add filament change support, uncomment #define ADVANCED_PAUSE_FEATURE. This feature also enables nozzle park when paused without further firmware modifications.

Resources & Credits

• Initial configuration based on u/qwewer1 post on Reddit, Marlin 2.0.x guide, SKR Mini E3 v2.0, Ender 3 on 06/14/2020.
• Shoutout to @linsomniac's repository, linsomniac/MarlinSKRMiniE3v2.0Files. These patches are used to augment vanilla Marlin to support the SKR Mini E3 v2.0 motherboard.
• Step Daemon for Marlin.